Fortress Biotech (FBIO) 10-K/A 9 Apr 21 2020 FY Annual report (amended) Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 18, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K/A
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Entity File Number	001-35366
Entity Registrant Name	Fortress Biotech, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5157386
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Address, Address Line One	2 Gansevoort Street
Entity Address, Address Line Two	9th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10014
City Area Code	781
Local Phone Number	652-4500
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 173,878,853
Entity Central Index Key	0001429260
Document Fiscal Year Focus	2020
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	FY
Common Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	Common Stock
Trading Symbol	FBIO
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		94,907,448
9.375% Series A Cumulative Redeemable Perpetual Preferred Stock [Member]
Document Information [Line Items]
Title of 12(b) Security	9.375% Series A Cumulative Redeemable Perpetual Preferred Stock
Trading Symbol	FBIOP
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		3,427,138

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 233,351	$ 136,858
Accounts receivable, net	19,349	13,539
Inventory	1,404	857
Other receivables - related party	744	865
Prepaid expenses and other current assets	6,723	4,133
Total current assets	261,571	156,252
Property and equipment, net	11,923	12,433
Operating lease right-of-use asset, net	20,487	21,480
Restricted cash	1,645	16,574
Long-term investment, at fair value	17,566	11,148
Intangible asset, net	14,629	7,377
Other assets	1,013	1,158
Total assets	328,834	226,422
Current liabilities
Accounts payable and accrued expenses	40,674	35,451
Interest payable	0	1,042
Interest payable - related party	0	92
Notes payable, short-term	0	7,220
Income taxes payable	136	0
Operating lease liabilities - short-term	1,849	1,784
Derivative warrant liability	0	27
Other current liabilities	5,300	0
Total current liabilities	47,959	45,616
Notes payable, long-term (net of debt discount of $8,323 and $5,086 at December 31, 2020 and December 31, 2019, respectively)	51,677	77,436
Operating lease liabilities, long-term	22,891	23,712
Partner company note payable, long-term	7,359	4,990
Other long-term liabilities	1,949	2,136
Total liabilities	131,835	153,890
Commitments and contingencies
Stockholders' equity
Cumulative redeemable perpetual preferred stock, $.001 par value, 15,000,000 authorized, 5,000,000 designated Series A shares, 3,427,138 and 1,341,167 shares issued and outstanding as of December 31, 2020 and December 31, 2019, respectively; liquidation value of $25.00 per share	3	1
Common stock, $.001 par value, 150,000,000 and 100,000,000 shares authorized, 94,877,492 and 74,027,425 shares issued and outstanding as of December 31, 2020 and December 31, 2019, respectively	95	74
Common stock issuable, 0 and 251,337 shares as of December 31, 2020 and December 31, 2019, respectively	0	500
Additional paid-in-capital	583,000	461,874
Accumulated deficit	(482,760)	(436,234)
Total stockholders' equity attributed to the Company	100,338	26,215
Non-controlling interests	96,661	46,317
Total stockholders' equity	196,999	72,532
Total liabilities and stockholders' equity	$ 328,834	$ 226,422

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Condensed Consolidated Balance Sheets
Debt instrument, unamortized discount	$ 8,323	$ 5,086
Preferred Stock, par value	$ 0.001	$ 0.001
Preferred Stock, shares authorized	15,000,000	15,000,000
Preferred Stock Shares Designated	5,000,000	5,000,000
Preferred Stock, shares issued	3,427,138	1,341,167
Preferred Stock, shares outstanding	3,427,138	1,341,167
Preferred Stock, liquidation preference per share	$ 25	$ 25
Common Stock, par value	$ 0.001	$ 0.001
Common Stock, shares authorized	150,000,000	100,000,000
Common Stock, shares issued	94,877,492	74,027,425
Common Stock, shares outstanding	94,877,492	74,027,425
Common Stock, Shares Subscribed but Unissued	0	251,337

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue
Product revenue, net	$ 44,531,000	$ 34,921,000
Revenue - related party	1,068,000	1,708,000
Net revenue	45,599,000	36,629,000
Operating expenses
Cost of goods sold - product revenue	14,594,000	10,532,000
Research and development	61,275,000	75,236,000
Research and development - licenses acquired	2,834,000	6,090,000
Selling, general and administrative	61,166,000	55,590,000
Total operating expenses	139,869,000	147,448,000
Income (loss) from operations	(94,270,000)	(110,819,000)
Other income (expense)
Interest income	1,518,000	2,559,000
Interest expense and financing fee	(15,326,000)	(11,849,000)
Change in fair value of derivative liability	(1,189,000)	(27,000)
Change in fair value of investments	6,418,000	0
Gain on deconsolidation of Caelum	0	18,476,000
Total other income (expense)	(8,579,000)	9,159,000
Loss before income tax expense	(102,849,000)	(101,660,000)
Income tax expense	136,000	0
Net loss	(102,985,000)	(101,660,000)
Less: net loss attributable to non-controlling interests	56,459,000	61,700,000
Net loss attributable to common stockholders	$ (46,526,000)	$ (39,960,000)
Net loss per common share - basic and diluted	$ (1.43)	$ (1.86)
Net loss per common share attributable to non - controlling interests - basic and diluted	(0.78)	(1.13)
Net loss per common share attributable to common stockholders - basic and diluted	$ (0.65)	$ (0.73)
Weighted average common shares outstanding - basic and diluted	72,005,181	54,711,838

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Thousands	Series A Preferred Stock [Member]	Common Stock [Member]	Shares Issuable [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Non-Controlling Interests [Member]	Total
Balance at Dec. 31, 2018	$ 1	$ 58	$ 659		$ 397,408	$ (396,274)	$ 17,891	$ 19,743
Balance (in shares) at Dec. 31, 2018	1,000,000	57,845,447
Stock-based compensation expense					13,188			13,188
Settlement of restricted stock units into common stock		$ 2			(2)
Settlement of restricted stock units into common stock (in shares)		1,905,367
Issuance of common stock under ESPP					123			123
Issuance of common stock under ESPP (in shares)		98,007
Issuance of common stock for at-the-market offering, net		$ 12			20,235			20,247
Issuance of common stock for at-the-market offering, net (in shares)		11,798,468
Preferred A dividends declared and paid					(2,559)			(2,559)
Issuance of Series A preferred stock for cash, net					5,307			5,307
Issuance of Series A preferred stock for cash, net (in shares)	301,875
Partner company's offering, net					78,607			78,607
Partner company's at-the-market offering, net					29,785			29,785
Issuance of partner company's common shares for license expenses			(164)		164
Issuance of partner company's common shares for research and development expenses					90			90
Issuance of Series A preferred stock for at-the-market offering, net					788			788
Issuance of Series A preferred stock for at-the-market offering, net (in shares)	39,292
Issuance of partner company warrants in conjunction with Horizon Notes					888			888
Common shares issuable for 2017 Subordinated Note Financing interest expense			500					500
Common shares issued for 2017 Subordinated Note Financing interest expense		$ 2	(495)		1,967			1,474
Common shares issued for 2017 Subordinated Note Financing interest expense (in shares)		1,637,936
Common shares issuable for Opus interest expense			281					281
Common shares issued for Opus interest expense			(281)		662			381
Common shares issued for Opus interest expense (in shares)		345,375
Common shares issued for Opus debt					500			500
Common shares issued for Opus debt (in shares)		396,825
Non-controlling interest in subsidiaries					(85,277)		85,277
Deconsolidation of Caelum non-controlling interest							4,849	4,849
Net loss attributable to non-controlling interest							(61,700)	(61,700)
Net loss attributable to common stockholders						(39,960)		(39,960)
Balance at Dec. 31, 2019	$ 1	$ 74	500		461,874	(436,234)	46,317	72,532
Balance (in shares) at Dec. 31, 2019	1,341,167	74,027,425
Stock-based compensation expense					13,451			13,451
Issuance of common stock related to equity plans		$ 2			16			18
Issuance of common stock related to equity plans (in shares)		2,335,808
Issuance of common stock under ESPP					253			253
Issuance of common stock under ESPP (in shares)		122,786
Issuance of common stock for at-the-market offering, net		$ 18			45,809			45,827
Issuance of common stock for at-the-market offering, net (in shares)		17,409,257
Preferred A dividends declared and paid					(6,515)			(6,515)
Repurchase of Series A preferred stock, net				$ (70)	(2)			(72)
Repurchase of Series A preferred stock (in shares)	(5,000)
Retirement of Series A preferred stock				$ 70	(70)
Issuance of Series A preferred stock for cash, net	$ 2				35,541			35,543
Issuance of Series A preferred stock for cash, net (in shares)	2,090,971
Partner company's offering, net					53,749			53,749
Partner company's at-the-market offering, net					70,988			70,988
Partner company's preferred stock offering, net					7,074			7,074
Issuance of common stock under partner company's ESPP					349			349
Partner company's dividends declared and paid					(237)			(237)
Issuance of partner company's common shares for research and development expenses					46			46
Partner company's exercise of warrants for cash					13			13
Partner company's exercise of options for cash					13			13
Reclass partner company's warrants from liability to equity					1,216			1,216
Issuance of partner company warrants in conjunction with Horizon Notes								0
Common shares issuable for 2017 Subordinated Note Financing interest expense		$ 1	$ (500)		1,816			1,317
Common shares issued for 2017 Subordinated Note Financing interest expense (in shares)		982,216
Issuance of warrants in conjunction with Oaktree Note					4,419			4,419
Non-controlling interest in subsidiaries					(106,803)		106,803
Net loss attributable to non-controlling interest							(56,459)	(56,459)
Net loss attributable to common stockholders						(46,526)		(46,526)
Balance at Dec. 31, 2020	$ 3	$ 95			$ 583,000	$ (482,760)	$ 96,661	$ 196,999
Balance (in shares) at Dec. 31, 2020	3,427,138	94,877,492

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities:
Net loss	$ (102,985)	$ (101,660)
Reconciliation of net loss to net cash used in operating activities:
Depreciation expense	2,280	1,922
Bad debt expense	49	100
Amortization of debt discount	5,622	3,321
Non-cash interest	697	0
Amortization of product revenue license fee	1,420	1,174
Amortization of operating lease right-of-use assets	1,625	1,558
Stock-based compensation expense	13,451	13,188
Issuance of common stock for service	18	0
Issuance of partner company's common shares for research and development expenses	46	90
Common shares issuable for 2017 Subordinated Note Financing interest expense	0	500
Common shares issued for 2017 Subordinated Note Financing interest expense	1,317	1,474
Common shares issuable for 2019 Notes interest expense	0	281
Common shares issued for 2019 Notes interest expense	0	381
Change in fair value of derivative liability	1,189	27
Change in fair value of investment	(6,418)	0
Gain on deconsolidation of Caelum	0	(18,476)
Research and development-licenses acquired, expense	2,788	6,000
Increase (decrease) in cash and cash equivalents resulting from changes in operating assets and liabilities:
Accounts receivable	(5,859)	(8,141)
Inventory	(547)	(179)
Other receivables - related party	121	1,230
Prepaid expenses and other current assets	(2,590)	1,798
Other assets	145	(882)
Accounts payable and accrued expenses	6,522	2,095
Accounts payable and accrued expenses - related party	0	(149)
Interest payable	(1,042)	8
Interest payable - related party	(92)	(5)
Income taxes payable	136	0
Lease liabilities	(1,388)	(1,365)
Other long-term liabilities	(187)	749
Net cash used in operating activities	(83,682)	(94,961)
Cash Flows from Investing Activities:
Purchase of research and development licenses	(4,038)	(4,650)
Purchase of property and equipment	(1,926)	(2,345)
Purchase of intangible asset	(1,200)	(2,400)
Purchase of short-term investment (certificates of deposit)	0	(5,000)
Redemption of short-term investment (certificates of deposit)	0	22,604
Deconsolidation of Caelum	0	(1,201)
Net cash provided by (used in) continuing investing activities	(7,164)	7,008
Net cash provided by discontinued investing activities	0	13,089
Net cash provided by (used in) investing activities	(7,164)	20,097
Cash Flows from Financing Activities:
Payment of Series A preferred stock dividends	(6,515)	(2,559)
Purchase of treasury stock	(70)	0
Payment of costs related to purchase of treasury stock	(2)	0
Proceeds from issuance of preferred stock	39,075	6,038
Payment of costs related to issuance of Series A preferred stock	(3,535)	(578)
Proceeds from issuance of common stock	47,509	20,680
Payment of costs related to issuance of common stock	(1,658)	(427)
Proceeds from issuance of Series A preferred stock for at-the-market offering	0	812
Payment of cost related to issuance of Series A preferred stock for at-the-market offering	0	(24)
Proceeds from issuance of common stock under ESPP	253	123
Proceeds from partner companies' ESPP	349	0
Partner company's dividends declared and paid	(237)	0
Proceeds from partner companies' sale of stock	57,729	86,180
Payment of costs related to partner companies' sale of stock	(4,049)	(6,671)
Proceeds from partner companies' at-the-market offering	72,570	30,526
Payment of costs related to partner companies' at-the-market offering	(1,498)	(741)
Proceeds from partner company's preferred stock offering	8,000	0
Payment of costs related to partner company's preferred stock offering	(913)	0
Proceeds from exercise of partner company's warrants	13	0
Proceeds from exercise of partner company's options	13	0
Installment payment related to intangible asset	(500)	0
Net cash provided by financing activities	172,410	146,714
Net increase in cash and cash equivalents and restricted cash	81,564	71,850
Cash and cash equivalents and restricted cash at beginning of period	153,432	81,582
Cash and cash equivalents and restricted cash at end of period	234,996	153,432
Supplemental disclosure of cash flow information:
Cash paid for interest	8,204	5,444
Cash paid for interest - related party	617	456
Supplemental disclosure of non-cash financing and investing activities:
Settlement of restricted stock units into common stock	2	2
Common shares issuable for license acquired	0	164
Issuance of partner company warrants in conjunction with Horizon Notes	0	888
Issuance of warrants in conjunction with Oaktree debt	4,419	0
Common shares issued from 2017 Subordinated Note Financing interest expense	500	0
Common shares issued for 2019 Notes	0	500
Unpaid fixed assets	31	187
Partner company's unpaid intangible assets	7,472	4,734
Partner company's previous paid offering cost	0	833
Reclass partner company's warrants from liability to equity	1,216	0
Unpaid partner company's offering cost	0	69
Unpaid partner company's at-the-market offering cost	84	0
Unpaid partner company's preferred stock offering cost	13	0
Unpaid debt offering cost	13	26
Unpaid at-the-market offering cost	30	6
Unpaid Series A preferred stock offering cost	0	153
Unpaid research and development licenses acquired	0	1,350
Retirement of Series A preferred stock	70	0
2017 Subordinated Note Financing [Member]
Cash Flows from Financing Activities:
Payment of debt issuance costs	(93)	(118)
Repayments of debt	(28,356)	0
Oaktree Note [Member]
Cash Flows from Financing Activities:
Proceeds from issuance of notes	60,000	0
Payment of debt issuance costs	(4,302)	0
2018 Venture Notes [Member]
Cash Flows from Financing Activities:
Payment of debt issuance costs	(58)	(134)
Repayments of debt	(21,707)	0
Opus Credit Facility (2019 Notes) [Member]
Cash Flows from Financing Activities:
Repayments of debt	(9,000)	0
Mustang Horizon Notes [Member]
Cash Flows from Financing Activities:
Proceeds from issuance of notes	0	15,000
Payment of debt issuance costs	0	(1,393)
Repayments of debt	(15,750)	0
IDB Note Payable [Member]
Cash Flows from Financing Activities:
Repayments of debt	$ (14,858)	$ 0

Organization and Description of

Organization and Description of Business	12 Months Ended
	Dec. 31, 2020
Organization and Description of Business
Organization and Description of Business	1. Organization and Description of Business Fortress Biotech, Inc. (“Fortress” or the “Company”) is a biopharmaceutical company dedicated to acquiring, developing and commercializing pharmaceutical and biotechnology products and product candidates, which the Company does at the Fortress level, at its majority-owned and majority-controlled subsidiaries and joint ventures, and at entities the Company founded and in which it maintains significant minority ownership positions. Fortress has a talented and experienced business development team, comprising scientists, doctors and finance professionals, who identify and evaluate promising products and product candidates for potential acquisition by new or existing partner companies. Fortress through its partner companies has executed such arrangements in partnership with some of the world’s foremost universities, research institutes and pharmaceutical companies, including City of Hope National Medical Center, Fred Hutchinson Cancer Research Center, St. Jude Children’s Research Hospital, Dana-Farber Cancer Institute, Nationwide Children's Hospital, Cincinnati Children's Hospital Medical Center, Columbia University, the University of Pennsylvania, and AstraZeneca plc. Following the exclusive license or other acquisition of the intellectual property underpinning a product or product candidate, Fortress leverages its business, scientific, regulatory, legal and finance expertise to help the partners achieve their goals. Partner companies then assess a broad range of strategic arrangements to accelerate and provide additional funding to support research and development, including joint ventures, partnerships, out-licensings, and public and private financings; to date, three partner companies are publicly-traded, and two have consummated strategic partnerships with industry leaders Alexion Pharmaceuticals, Inc. and InvaGen Pharmaceuticals, Inc. (a subsidiary of Cipla Limited). Several of our partner companies possess licenses to product candidate intellectual property, including Aevitas Therapeutics, Inc. (“Aevitas”), Avenue Therapeutics, Inc. (“Avenue”), Baergic Bio, Inc. (“Baergic”), Caelum Biosciences, Inc. (“Caelum”), Cellvation, Inc. (“Cellvation”), Checkpoint Therapeutics, Inc. (“Checkpoint”), Cyprium Therapeutics, Inc. (“Cyprium”), Helocyte, Inc. (“Helocyte”), Journey Medical Corporation (“Journey” or “JMC”), Mustang Bio, Inc. (“Mustang”) and Oncogenuity, Inc. ("Oncogenuity"). Liquidity and Capital Resources Since inception, the Company’s operations have been financed primarily through the sale of equity and debt securities, from the sale of partner companies, the proceeds from the exercise of warrants and stock options. The Company has incurred losses from operations and negative cash flows from operating activities since inception and expects to continue to incur substantial losses for the next several years as it continues to fully develop and prepare regulatory filings and obtain regulatory approvals for its existing and new product candidates. The Company’s current cash and cash equivalents are sufficient to fund operations for at least the next 12 months. However, the Company will need to raise additional funding through strategic relationships, public or private equity or debt financings, sale of a partner company, grants or other arrangements to fully develop and prepare regulatory filings and obtain regulatory approvals for the existing and new product candidates, fund operating losses, and, if deemed appropriate, establish or secure through third parties manufacturing for the potential products, sales and marketing capabilities. If such funding is not available or not available on terms acceptable to the Company, the Company’s current development plan and plans for expansion of its selling, general and administrative infrastructure will be curtailed. The Company also has the ability, subject to limitations imposed by Rule 144 of the Securities Act of 1933 and other applicable laws and regulations, to raise money from the sale of common stock of the public companies in which it has ownership positions. In addition to the foregoing, the Company does not expect any material impact on its development timelines, revenue levels and its liquidity due to the worldwide spread of COVID-19 (except as may be implicated by the Material Adverse Effect claimed by InvaGen in connection with their agreement with Avenue). However, the Company is continuing to assess the impact the spread of COVID-19 may have on its operations. Avenue will also continue to assess the alleged Material Adverse Effect claimed by InvaGen.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The Company’s consolidated financial statements include the accounts of the Company and the accounts of the Company’s subsidiaries, listed above. All intercompany balances and transactions have been eliminated. The accompanying consolidated financial statements include the accounts of the Company’s subsidiaries. For consolidated entities where the Company owns less than 100% of the subsidiary, the Company records net loss attributable to non-controlling interests in its consolidated statements of operations equal to the percentage of the economic or ownership interest retained in such entities by the respective non-controlling parties. The Company also consolidates subsidiaries in which it owns less than 50% of the subsidiary but maintains voting control. The Company continually assesses whether changes to existing relationships or future transactions may result in the consolidation or deconsolidation of partner companies. Use of Estimates The Company’s consolidated financial statements include certain amounts that are based on management’s best estimates and judgments. The Company’s significant estimates include, but are not limited to, useful lives assigned to long-lived assets, fair value of stock options and warrants, stock-based compensation, common stock issued to acquire licenses, investments, accrued expenses, provisions for income taxes and contingencies. Due to the uncertainty inherent in such estimates, actual results may differ from these estimates. Revenue Recognition The Company recognizes revenue under Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers Step 1: Identify the contract with the customer Step 2: Identify the performance obligations in the contract Step 3: Determine the transaction price Step 4: Allocate the transaction price to the performance obligations in the contract Step 5: Recognize revenue when the company satisfies a performance obligation In order to identify the performance obligations in a contract with a customer, a company must assess the promised goods or services in the contract and identify each promised good or service that is distinct. A performance obligation meets ASC 606’s definition of a “distinct” good or service (or bundle of goods or services) if both of the following criteria are met: The customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct). The entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract). If a good or service is not distinct, the good or service is combined with other promised goods or services until a bundle of goods or services is identified that is distinct. The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The transaction price is allocated to each performance obligation on a relative standalone selling price basis. The transaction price allocated to each performance obligation is recognized when that performance obligation is satisfied, at a point in time or over time as appropriate. The Company recognizes product revenue from sales of Ximino®, Targadox®, Exelderm®, Luxamend® and Ceracade®. The Company’s performance obligation to deliver products is satisfied at the point in time that the goods are delivered to the customer, which is when the customer obtains title to and has the risks and rewards of ownership of the products. The Company has variable consideration in the form of rights of return, coupons, and price protection to customers. The Company uses an expected value method to estimate variable consideration and whether the transaction price is constrained. Payment is due within months of when the customer is invoiced, with discounts for prompt payment. The Company recorded expense related to returns reserve of $1.3 million and $2.9 million for the years ended December 31, 2020 and December 31, 2019, respectively. Because the Company’s agreements for sales of product to its distributors can be cancelled early, prior to the termination date, they are deemed to have an expected duration of one year or less, and as such, the Company has elected the practical expedient in ASC 606-10-50-14(a) to not disclose information about its remaining performance obligations. Discontinued Operations Pursuant to the discontinued operations criteria set forth in ASC Subtopic 205-20-45, Presentation of Financial Statements Fair Value Measurement The Company follows accounting guidance on fair value measurements for financial assets and liabilities measured at fair value on a recurring basis. Under the accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance requires fair value measurements be classified and disclosed in one of the following three categories: Level 1 Level 2 Level 3 : Unobservable inputs which are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. Certain of the Company’s financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as accounts payable, accrued expenses and other current liabilities. Segment Reporting The Company operates in two operating and reportable Cash and Cash Equivalents The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash and cash equivalents at December 31, 2020 and at December 31, 2019 consisted of cash and certificates of deposit in institutions in the United States. Balances at certain institutions have exceeded Federal Deposit Insurance Corporation insured limits and U.S. government agency securities. Short-term Investments The Company classifies its certificates of deposit as cash and cash equivalents or held to maturity in accordance with ASC 320, Investments - Debt and Equity Securities At December 31, 2020, the Company had approximately $76.8 million and $15.0 million, respectively, in certificates of deposit, which the Company classified as cash and cash equivalents. There were no short term investments classified as held-to-maturity as of December 31, 2020. Property and Equipment Computer equipment, furniture & fixtures and machinery & equipment are recorded at cost and depreciated using the straight-line method over the estimated useful life of each asset. Leasehold improvements are amortized over the shorter of the estimated useful lives or the term of the respective leases. In connection with Mustang’s cell processing facility, Mustang incurred costs for the design and construction of the facility and the purchase of equipment; $0.5 million and $1.2 million are recorded in fixed assets – construction in process on the balance sheet at December 31, 2020 and 2019, respectively. Upon completion of the facility’s construction, all costs associated with the buildout will be recorded as leasehold improvements and amortized over the shorter of the estimated useful lives or the term of the respective leases, upon the improvement being placed in service. Restricted Cash The Company records cash held in trust or pledged to secure certain debt obligations as restricted cash. As of December 31, 2020, the Company had $1.6 million of restricted cash representing pledges to secure letters of credit in connection with certain office leases. As of December 31, 2019, the Company had $16.6 million of restricted cash collateralizing a note payable of $15.0 million and $1.6 million in certain pledges to secure letters of credit in connection with certain office leases. The following table provides a reconciliation of cash, cash equivalents, and restricted cash from the consolidated balance sheets to the consolidated statements of cash flows for the years ended 2020, and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ($ in thousands) ​ 2020 ​ 2019 Cash and cash equivalents $ 233,351 $ 136,858 Restricted cash ​ 1,645 ​ 16,574 Total cash and cash equivalents and restricted cash ​ $ 234,996 ​ $ 153,432 ​ Inventories Inventories comprise finished goods, which are valued at the lower of cost and net realizable value, on a first-in, first-out basis. The Company evaluates the carrying value of inventories on a regular basis, taking into account anticipated future sales compared with quantities on hand, and the remaining shelf life of goods on hand. Accounts Receivable, net Accounts receivable consists of amounts due to the Company for product sales of JMC. The Company’s accounts receivable reflects discounts for estimated early payment and for product estimated returns. Accounts receivable are stated at amounts due from customers, net of an allowance for doubtful accounts that are outstanding longer than the contractual payment terms are considered past due. The Company determines its allowance for doubtful accounts by considering a number of factors, including the length of time trade accounts receivable are past due and the customer’s current ability to pay its obligation to the Company. The Company writes off accounts receivable when they become uncollectible. For the years ended December 31, 2020 and 2019 the allowance for doubtful accounts was approximately $0.1 million and $0.1 million, respectively. The allowance for product estimated returns were $4.6 million and $5.4 million at December 31, 2020 and 2019, respectively, representing constrained revenue. Investments at Fair Value The Company elects the fair value option for its long-term investments at fair value (see Note 6). The decision to elect the fair value option, which is irrevocable once elected, is determined on an instrument by instrument basis and applied to an entire instrument. The net gains or losses, if any, on an investment for which the fair value option has been elected are recognized as a change in fair value of investments on the Consolidated Statements of Operations. The Company has various processes and controls in place to ensure that fair value is reasonably estimated. While the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date. Accounting for Warrants at Fair Value The Company classifies as liabilities any contracts that (i) require net-cash settlement (including a requirement to net-cash settle the contract if an event occurs and if that event is outside the control of the Company) or (ii) give the counterparty a choice of net-cash settlement or settlement in shares (physical settlement or net-share settlement). The accounting treatment of derivative financial instruments requires that the Company record the warrants at their fair values as of the inception date of the agreement and at fair value as of each subsequent balance sheet date. Any change in fair value is recorded as non-operating, non-cash income or expense for each reporting period at each balance sheet date. The Company reassesses the classification of its derivative instruments at each balance sheet date. If the classification changes as a result of events during the period, the contract is reclassified as of the date of the event that caused the reclassification. The Company assessed the classification of warrants issuable in connection with 2018 Venture Notes and determined that the Cyprium Contingently Issuable Warrants met the criteria for liability classification. Accordingly, the Company classified the Cyprium Contingently Issuable Warrants as a liability at their fair value and adjusted the instruments to fair value at each balance sheet date until the warrants were issued. Any change in the fair value of the Cyprium Contingently Issuable Warrants is recognized as “change in the fair value of derivative liabilities” in the Consolidated Statements of Operations. During the year ended December 31, 2020, Cyprium raised approximately $8.0 million in Cumulative Redeemable Perpetual Preferred Shares (“Cyprium Offering,” see Note 14). The Cyprium Offering coupled with the repayment of the 2018 Venture Debt (see Note 10), triggered the issuance of the Cyprium Warrant, in that a price per share could be established. As such these events resulted in Cyprium recording the Cyprium Warrant as issued rather than contingently issuable. Opus Credit Facility, with Detachable Warrants The Company accounted for the Opus Credit Facility (see Note 10) with detachable warrants in accordance with ASC 470, Debt The Company recorded the related issue costs and value ascribed to the warrants as a debt discount of the Opus Credit Facility. The discount was amortized utilizing the effective interest method over the term of the Opus Credit Facility. The unamortized discount, if any, upon repayment of the Opus Credit Facility would be expensed to interest expense. In accordance with ASC Subtopic 470-20, the Company determined the weighted average effective interest rate of the debt was approximately 16% at December 31, 2019. The Company also evaluated the Opus Credit Facility and warrants in accordance with the provisions of ASC 815, Derivatives and Hedging As of December 31, 2019, Opus dissolved and distributed its assets among its Limited Partners. The dissolution did not impact any of the terms under the Opus Credit Facility. During the year ended December 31, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $9.0 million balance previously outstanding under the Opus Credit Facility/2019 Notes (see Note 10). Issuance of Debt and Equity The Company issues complex financial instruments which include both equity and debt features. The Company analyzes each instrument under ASC 480, Distinguishing Liabilities from Equity, Derivatives and Hedging Debt The Company accounted for the Oaktree Note with detachable warrants in accordance with ASC 470, Debt The Company recorded the related issue costs and value ascribed to the warrants as a debt discount of the Oaktree Note. The discount was amortized utilizing the effective interest method over the term of the Oaktree Note. The unamortized discount, if any, upon repayment of the Oaktree Note would be expensed to interest expense. In accordance with ASC Subtopic 470-20, the Company determined the weighted average effective interest rate of the debt was approximately 15.13% at December 31, 2020. The Company also evaluated the Oaktree Note and warrants in accordance with the provisions of ASC 815, Derivatives and Hedging Long-Lived Assets Long-lived assets, primarily fixed assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets might not be recoverable. The Company will perform a periodic assessment of assets for impairment in the absence of such information or indicators. Conditions that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or a significant adverse change that would indicate that the carrying amount of an asset or group of assets is not recoverable. For long-lived assets to be held and used, the Company would recognize an impairment loss only if its carrying amount is not recoverable through its undiscounted cash flows and measures the impairment loss based on the difference between the carrying amount and estimated fair value. As of December 31, 2020 and 2019 there were no indicators of impairment. Research and Development Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Upfront and milestone payments due to third parties that perform research and development services on the Company’s behalf will be expensed as services are rendered or when the milestone is achieved. Research and development costs primarily consist of personnel related expenses, including salaries, benefits, travel, and other related expenses, stock-based compensation, payments made to third parties for license and milestone costs related to in-licensed products and technology, payments made to third party contract research organizations for preclinical and clinical studies, investigative sites for clinical trials, consultants, the cost of acquiring and manufacturing clinical trial materials, and costs associated with regulatory filings, laboratory costs and other supplies. In accordance with ASC 730-10-25-1, Research and Development Contingencies The Company records accruals for contingencies and legal proceedings expected to be incurred in connection with a loss contingency when it is probable that a liability has been incurred and the amount can be reasonably estimated. If a loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, would be disclosed. Leases Effective January 1, 2019, the Company accounts for its leases under ASC 842, Leases In calculating the right-of-use asset and lease liability, the Company elects to combine lease and non-lease components. The Company continues to account for leases in the prior period consolidated financial statements under ASC Topic 840, Leases Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees over the requisite service period based on the estimated grant-date fair value of the awards and forfeitures, which are recorded upon occurence. For stock-based compensation awards to non-employees, prior to the adoption of ASU 2018-07 on January 1, 2019, the Company remeasured the fair value of the non-employee awards at each reporting period prior to vesting and finally at the vesting date of the award. Changes in the estimated fair value of these non-employee awards were recognized as compensation expense in the period of change. Subsequent to the adoption of ASU 2018-07, the Company recognizes non-employees compensation costs over the requisite service period based on a measurement of fair value for each stock award at the time the award is granted. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. Income Taxes The Company accounts for income taxes under ASC 740, Income Taxes ASC 740 also clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements and prescribes a recognition threshold and measurement process for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more-likely-than-not to be sustained upon examination by taxing authorities. ASC 740 also provides guidance on de-recognition, classification, interest and penalties, accounting in interim period, disclosure and transition. Based on the Company’s evaluation, it has been concluded that there are no significant uncertain tax positions requiring recognition in the Company’s financial statements. The 2017 through 2019 tax years are the only periods subject to examination upon filing of appropriate tax returns. The Company believes that its income tax positions and deductions would be sustained on audit and does not anticipate any adjustments that would result in a material change to its financial position. The Company’s policy for recording interest and penalties associated with audits is to record such expense as a component of income tax expense. There were no amounts accrued for penalties or interest as of or during the years ended December 31, 2020 and 2019. Management is currently unaware of any issues under review that could result in significant payments, accruals or material deviations from its position. Non-Controlling Interests Non-controlling interests in consolidated entities represent the component of equity in consolidated entities held by third parties. Any change in ownership of a subsidiary while the controlling financial interest is retained is accounted for as an equity transaction between the controlling and non-controlling interests. Comprehensive Loss The Company’s comprehensive loss is equal to its net loss for all periods presented. Recently Adopted Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820), - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement In June 2018, the FASB issued ASU 2018-07, “Improvements to Nonemployee Share-Based Payment Accounting” In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480) and Derivatives and Hedging (Topic 815): I. Accounting for Certain Financial Instruments with Down Round Features; II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements Recent Accounting Pronouncements “Financial Instruments – Credit Losses” In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. The Company adopted the new guidance in the first quarter of 2021 and the adoption of this guidance did not to have a material impact on the financial statements. ​

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2020
Discontinued Operations
Discontinued Operations	3. Discontinued Operations On November 14, 2018, the Company announced that it had reached an agreement with NHC Holdings, LLC (“NHC”) to sell all of its shares of National Holdings Corporation, a diversified independent brokerage company (together with its subsidiaries, herein referred to as “NHLD” or “National”) for total consideration of $22.9 million. Pursuant to the terms of the agreement with NHC the sale of the shares was subject to two closings. The first closing occurred on November 14, 2018 in which the Company sold approximately 3.0 million of its shares in NHLD and received $9.8 million in proceeds. The second closing occurred on February 11, 2019 upon the receipt of FINRA approval of the sale in which the Company received $13.1 million in proceeds for the sale of its remaining 4.0 million shares of NHLD to NHC and two other minority holders. At December 31, 2019, the Company had no ownership interest in National. The table below depicts the cash flows from the transaction for the year ended December 31, 2019: ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ($ in thousands) 2019 Investing activities ​ Proceeds from sale of National ​ $ 13,089 Total cash provided by discontinued investing activities ​ $ 13,089 ​

Collaboration and Stock Purchas

Collaboration and Stock Purchase Agreements	12 Months Ended
	Dec. 31, 2020
Collaboration and Stock Purchase Agreements
Collaboration and Stock Purchase Agreements	4. Collaboration and Stock Purchase Agreements Caelum Agreement with Alexion In January 2019, Caelum, a subsidiary of the Company at that time, entered into a Development, Option and Stock Purchase Agreement (the "DOSPA") and related documents by and among Caelum, Alexion Therapeutics, Inc. ("Alexion"), the Company and Caelum security holders parties thereto (including Fortress, the "Sellers"). Under the terms of the agreement, Alexion purchased a 19.9% minority equity interest in Caelum for $30 million. Additionally, Alexion has agreed to make potential payments to Caelum upon the achievement of certain developmental milestones, in exchange for which Alexion obtained a contingent exclusive option to acquire the remaining equity in Caelum. The agreement also provides for potential additional payments, in the event Alexion exercises the purchase option, for up to $500 million, which includes an upfront option exercise payment and potential regulatory and commercial milestone payments. Alexion’s 19.9% ownership does not participate in the potential additional payments. The Company deconsolidated its holdings in Caelum immediately prior to the execution of the DOSPA. Following the DOSPA execution, the Company owns approximately 40% of the issued and outstanding capital stock of Caelum. The following table provides a summary of the assets and liabilities of Caelum impacted by the deconsolidation: ​ ​ ​ ​ ​ ​ ​ January ($ in thousands) 2019 ASSETS ​ Current assets ​ Cash and cash equivalents ​ $ 1,201 Prepaid expenses and other current assets ​ 6 Total current assets ​ $ 1,207 ​ ​ ​ ​ LIABILITIES ​ Current liabilities ​ Accounts payable and accrued expenses ​ $ 2,246 Interest payable ​ 198 Interest payable - related party ​ 106 Note payable - related party ​ 929 Note payable ​ 9,914 Warrant liability ​ 991 Total current liabilities ​ 14,384 Net liability impacted by deconsolidation ​ $ 13,177 ​ In connection with this transaction the Company recorded a gain resulting from the deconsolidation of Caelum on its consolidated financial statements for the year ended December 31, 2019: ​ ​ ​ ​ ​ ​ ​ Gain on ​ ​ deconsolidation of ($ in thousands) Caelum Fair value of Caelum ​ $ 11,148 Net liabilities deconsolidated ​ 13,177 Non-controlling interest share ​ (4,849) Write off of MSA fees due Fortress ​ (1,000) Gain on deconsolidation of Caelum ​ $ 18,476 ​ In December 2019, following FDA feedback which resulted in the redesign and expansion of Caelum’s planned clinical development program for CAEL-101, Caelum entered into an Amended and Restated DOSPA (“A&R DOSPA”), which amended the terms of the existing agreement with Alexion. The amendment modified the terms of Alexion’s option to acquire the remaining equity in Caelum based on data from the expanded Phase II/III trials. The amendment also modified the development-related milestone events associated with the initial $30.0 million in contingent payments, provided for an additional $20.0 million in upfront funding, as well as funding of $60.0 million in exchange for an additional equity interest in Caelum at fair value upon achievement of a specific development-related milestone event. On December 12, 2020, AstraZeneca (“AZ”) announced its intention to acquire Alexion, with the acquisition expected to close by the third quarter of 2021, as the acquisition is subject to approval by both AZ and Alexion shareholders, as well as certain regulatory approvals, share listing approvals, and other customary closing conditions. The acquisition of Alexion by AZ triggers the Change of Control clause in the A&R DOSPA, such that Alexion’s purchase option expires on the date that is six months after the closing of any Change of Control. Avenue Agreement with InvaGen On November 12, 2018, Avenue entered into a Stock Purchase and Merger Agreement (the “Avenue SPMA”) with InvaGen Pharmaceuticals Inc. (“InvaGen”), and Madison Pharmaceuticals Inc. (the “Merger Sub”), under which Avenue would be sold to InvaGen in a two-stage transaction. The first stage of the strategic transaction between InvaGen and Avenue closed in February 2019. InvaGen acquired approximately 5.8 million shares of Avenue’s common stock at $6.00 per share for total gross consideration of $35.0 million, representing a 33.3% stake in Avenue’s capital stock on a fully diluted basis. At the second stage closing, InvaGen would acquire the remaining shares of Avenue’s common stock, pursuant to a reverse triangular merger with Avenue remaining as the surviving entity. The second stage closing is subject to the satisfaction of certain closing conditions, including conditions pertaining to the FDA approval, labeling, scheduling and the absence of any Risk Evaluation and Mitigation Strategy or similar restrictions in effect with respect to IV Tramadol, as well as the expiration of any waiting period applicable to the acquisition under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (“HSR”). In October 2020, InvaGen communicated to Avenue that it believes a Material Adverse Effect (as defined in the Avenue SPMA) has occurred due to the impact of the COVID-19 pandemic on potential commercialization and projected sales of IV Tramadol, which means it is possible InvaGen could attempt to avoid its obligation to consummate the second stage closing under the Avenue SPMA, terminate the Avenue SPMA, and/or pursue monetary claims against Avenue and/or Fortress. Avenue disagrees with InvaGen’s assertion that a Material Adverse Effect has occurred and has advised InvaGen of this position. In February 2020, the U.S. Food and Drug Administration (“FDA”) accepted the submission of Avenue’s’ New Drug Application (“NDA”) for IV Tramadol for review and assigned a Prescription Drug User Fee Act (“PDUFA”) date of October 10, 2020. In October 2020, Avenue announced that it had received a Complete Response Letter (“CRL”) from the FDA regarding Avenue’s NDA for IV Tramadol. The FDA held a Type A meeting with Avenue in November 2020 to discuss the issues outlined in the CRL. On February 12, 2021 Avenue resubmitted its NDA to the FDA for IV Tramadol. The NDA resubmission followed the receipt of the official minutes from Avenue’s Type A meeting with the FDA. The NDA resubmission included revised language relating to the proposed product label and a report relating to terminal sterilization validation. On February 26, 2021, Avenue received an acknowledgement letter from the FDA that Avenue’s resubmission of its NDA is a complete, class 1 response to the CRL, and a PDUFA goal date was set for April 12, 2021. In connection with the resubmission of Avenue’s NDA, InvaGen communicated to Avenue that it believes the proposed label for IV Tramadol under certain circumstances would constitute a Material Adverse Effect on the purported basis that the proposed label for IV Tramadol would make the product commercially unviable, and in addition that the indiciation that the FDA approves may fail to satisfy a condition precedent to InvaGen’s obligation to consummate the second stage closing of the Avenue SPMA. Avenue has notified InvaGen that it disagrees with InvaGen’s assertions. Nevertheless, InvaGen may seek to avoid its obligation to consummate the second stage closing under the Avenue SPMA, terminate the Avenue SPMA, and/or pursue monetary claims against Avenue and/or Fortress. Over the past several months, Avenue has communicated with InvaGen relating to InvaGen’s assertions. Nevertheless, InvaGen has communicated to Avenue its desire to consider all options on the proposed merger, including the option to not consummate the merger. This indicates that InvaGen may attempt to avoid its obligations under the Avenue SPMA to consummate the merger, terminate the Avenue SPMA, and/or pursue monetary claims against Avenue and/or Fortress. As a result, the possible timing and likelihood of the completion of the merger are uncertain, and, accordingly, there can be no assurance that such transaction will be completed on the expected terms, anticipated schedule, or at all. During the pendency of any dispute regarding these matters, Avenue may be, and so long as the Avenue SPMA remains in place Avenue will be, prohibited from engaging in a change-of-control transaction, selling its rights to IV Tramadol or effecting an equity or debt financing, in each case without the prior written consent of InvaGen. ​ Subject to the terms and conditions described in the Avenue SPMA, InvaGen may also provide interim financing to Avenue in an amount of up to $7.0 million during the time period between February 8, 2019 and the Merger Transaction. Any amounts drawn on the interim financing will be deducted from the aggregate consideration payable to Company stockholders by virtue of the Merger Transaction. There have been no amounts drawn upon this interim financing as of December 31, 2020. Prior to the closing of the Merger Transaction, Avenue will enter into a Contingent Value Rights Agreement (the “CVR Agreement”) with a trust company as rights agent, pursuant to which holders of common shares of Avenue, other than InvaGen (each, a “Holder”), will be entitled to receive on Contingent Value Right (“CVR”) for each share held immediately prior to the Merger Transaction. Each CVR represents the right of its holder to receive a contingent cash payment pursuant to the CVR Agreement upon the achievement of certain milestones. If, during the period commencing on the day following the closing of the Merger Transaction until December 31, 2028, IV Tramadol generates at least $325 million or more in Net Sales (as defined in the CVR Agreement) in a calendar year, each Holder shall be entitled to receive their pro rata share of (i) if the product generated less than $400 million in Net Sales during such calendar year, 10% of Gross Profit (as defined in the CVR Agreement), (ii) if the product generated between $400 million and $500 million in Net Sales during such calendar year, 12.5% of Gross Profit, or (iii) if the product generated more than $500 million in Net Sales during such calendar year, 15% of Gross Profit. Additionally, at any time beginning on January 1, 2029 that IV Tramadol has generated at least $1.5 billion in aggregate Net Sales, then with respect to each calendar year in which IV Tramadol generates $100 million or more in Net Sales, each Holder shall be entitled to receive their pro rata share of an amount equal to 20% of the Gross Profit generated by IV Tramadol. These additional payments will terminate on the earlier of December 31, 2036 and the date (which may be extended by up to 6 months) that any person has received approval from the FDA for an Abbreviated New Drug Application or an FDA AP-rated 505(b)(2) NDA using IV Tramadol.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2020
Property and Equipment
Property and Equipment	5. Property and Equipment Fortress’ property and equipment consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Useful Life December 31, December 31, ($ in thousands) ​ (Years) ​ 2020 ​ 2019 Computer equipment ​ 3 ​ $ 663 ​ $ 648 Furniture and fixtures ​ 5 ​ 1,199 ​ 1,162 Machinery & equipment ​ 5 ​ 5,748 ​ 4,594 Leasehold improvements ​ 2-15 ​ 10,580 ​ 9,358 Construction in progress 1 ​ N/A ​ 499 ​ 1,157 Total property and equipment ​ ​ ​ ​ 18,689 ​ 16,919 Less: Accumulated depreciation ​ ​ ​ ​ (6,766) ​ (4,486) Property and equipment, net ​ ​ ​ ​ $ 11,923 ​ $ 12,433 ​ Note 1: Relates to the Mustang cell processing facility. Depreciation expenses of Fortress’ property and equipment for the years ended December 31, 2020 and 2019 was $2.3 million and $1.9 million, respectively, and was recorded in research and development, and selling, general and administrative expense in the Consolidated Statements of Operations.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Measurements
Fair Value Measurements	6. Fair Value Measurements Certain of the Company’s financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as accounts payable, accrued expenses and other current liabilities. Fair Value of Caelum The Company values its investment in Caelum in accordance with ASC Topic 820, Fair Value Measurements and Disclosures As of December 31, 2019, the estimated fair value of the Company’s investment in Caelum was $11.1 million based on a per share value of $1.54. As of December 31, 2019, the following inputs were utilized to derive the value: risk free rate of return of 1.6%, volatility of 70% and a discount for lack of marketability of 28.7%. Caelum Warrant Liability The fair value of Caelum's warrant liability, which was issued in connection with Caelum’s convertible note, was written up to the full value of the liability prior to the conversion of the notes in January 2019 (see Note 10). The fair value was measured using a Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Caelum’s warrant liabilities that are categorized within Level 3 of the fair value hierarchy as of January 2019 was as follows: ​ ​ ​ ​ ​ ​ January ​ 2019 Risk-free interest rate 2.905% - 2.909 % Expected dividend yield — % Expected term in years 3.84 - 3.96 ​ Expected volatility 70 % ​ In connection with the DOSPA Caelum's convertible notes automatically converted into common shares of Caelum and the warrant liability payable to the placement agent in connection with the placement of the convertible notes was also issued (see Note 10). ​ ​ ​ ​ ​ ​ ​ Fair Value of ​ ​ Derivative ​ ​ Warrant ($ in thousands) Liability Beginning balance at January 1, 2019 ​ $ 991 Issuance of warrant due to conversion of note ​ (991) Ending balance at December 31, 2019 ​ $ — ​ Caelum Convertible Notes Caelum’s convertible debt was measured at fair value using the Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Caelum’s convertible debt that is categorized within Level 3. As of December 31, 2018, conversion of the Caelum Convertible Notes was probable and as such the fair value approximated cost. The Caelum Convertible Notes were converted during 2019. As of January 2019 the following inputs were utilized to derive the notes’ fair value: ​ ​ ​ ​ ​ ​ ​ January ​ 2019 Risk-free interest rate 2.302 % Expected dividend yield — % Expected term in years 0.32 ​ Expected volatility 67 % ​ ​ ​ ​ ​ ​ Caelum ​ ​ Convertible ​ ​ Notes, at fair ($ in thousands) ​ value Beginning balance at January 1, 2019 ​ $ 9,914 Change in fair value of convertible notes ​ (9,914) Ending balance at December 31, 2019 ​ $ — ​ Cyprium Warrant Liability The fair value of the Cyprium Contingently Issuable Warrants in connection with the 2018 Venture Debt was determined by applying management’s estimate of the probability of issuance of the Contingently Issuable Warrants together with an option-pricing model, with the following key assumptions: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Risk-free interest rate 0.69 % 1.92 % Expected dividend yield — — ​ Expected term in years 10.0 10 ​ Expected volatility 85 % 93 % Probability of issuance of the warrant 100 % 5 % ​ ​ ​ ​ ​ ​ ​ Cyprium ​ ​ Contingently ​ ​ Issuable Warrant ($ in thousands) ​ Liability Beginning balance at January 1, 2019 ​ $ — Change in fair value ​ ​ 27 Ending balance at December 31, 2019 ​ $ 27 Change in fair value ​ ​ 1,189 Reclass partner company's warrants from liability to equity ​ ​ (1,216) Ending balance at December 31, 2020 ​ $ — ​ The following tables classify into the fair value hierarchy of Fortress’ financial instruments, measured at fair value on a recurring basis on the Consolidated Balance Sheets as of December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement as of December 31, 2020 ($ in thousands) Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ Fair value of investment in Caelum ​ $ — ​ $ — ​ $ 17,566 ​ $ 17,566 Total ​ $ — ​ $ — ​ $ 17,566 ​ $ 17,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement as of December 31, 2019 ($ in thousands) Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ Fair value of investment in Caelum $ — $ — $ 11,148 $ 11,148 Total $ — $ — $ 11,148 $ 11,148 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement as of December 31, 2019 ($ in thousands) Level 1 Level 2 Level 3 Total Liabilities ​ ​ ​ ​ Warrant liabilities $ — $ — $ 27 $ 27 Total $ — $ — $ 27 $ 27 ​ The table below provides a roll forward of the changes in fair value of Level 3 financial instruments for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment in ​ ​ Warrant ​ ​ ​ ($ in thousands) Caelum Liabilities Total Balance at December 31, 2019 ​ $ 11,148 ​ $ 27 ​ $ 11,175 Change in fair value ​ ​ — ​ ​ 1,189 ​ ​ 1,189 Reclass partner company's warrants from liability to equity ​ ​ — ​ ​ (1,216) ​ ​ (1,216) Change in fair value of investments ​ ​ 6,418 ​ ​ — ​ ​ 6,418 Balance at December 31, 2020 ​ $ 17,566 ​ $ — ​ $ 17,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment ​ Caelum Convertible Warrants ​ ​ ($ in thousands) in Caelum ​ ​ Notes ​ liabilities Total Balance at December 31, 2018 ​ $ — ​ $ 9,914 ​ $ 991 ​ $ 10,905 Conversion of convertible notes ​ — ​ (9,914) ​ — ​ (9,914) Issuance of warrant ​ — ​ — ​ (991) ​ (991) Fair value of investment ​ 11,148 ​ — ​ — ​ 11,148 Change in fair value of derivative liability ​ — ​ — ​ 27 ​ 27 Balance at December 31, 2019 ​ $ 11,148 ​ $ — ​ $ 27 ​ $ 11,175 ​

Licenses Acquired

Licenses Acquired	12 Months Ended
	Dec. 31, 2020
Licenses Acquired
Licenses Acquired	7. Licenses Acquired In accordance with ASC 730-10-25-1, Research and Development For the years ended December 31, 2020 and 2019, the Company’s research and development-licenses acquired are comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ ​ December 31, ($ in thousands) 2020 2019 Partner companies: ​ ​ Avenue ​ $ — ​ $ 1,000 Aevitas ​ ​ 62 ​ ​ — Baergic ​ 11 ​ 3,290 Cellvation ​ 1 ​ — Helocyte ​ ​ — ​ ​ 450 Mustang ​ ​ 2,489 ​ ​ 1,350 Oncogenuity ​ ​ 271 ​ ​ — Total ​ $ 2,834 ​ $ 6,090 ​ Aevitas License Agreement with University of Massachusetts On December 17, 2020, Aevitas entered into an exclusive license agreement (the “UMass license”) with the University of Massachusetts to obtain an exclusive license to the University’s intellectual property rights which relate to gene therapy for Factor H deficiency. For the year ended December 31, 2020, Aevitas recorded $0.1 million in connection with the execution of the UMass License. Development milestone payments totaling approximately $1.0 million in the aggregate are due upon achievement of each milestone. Four net sales milestones totaling $4.0 million are due on licensed products as are high single digit royalties due on aggregate, annual, worldwide net sales of licensed products. Avenue License Agreement with Revogenex Ireland Ltd In 2015, the Company purchased an exclusive license to IV Tramadol for the U.S. market from Revogenex, a privately held company in Dublin, Ireland, for an upfront fee of $3.0 million. The Company then assigned all of its right, title and interest to the exclusive license to Avenue. Under the terms of the license agreement assumed by Avenue, Revogenex is eligible to receive additional milestone payments upon the achievement of certain development milestones. As of December 31, 2020, one remaining development milestone of $3.0 million for approval of IV Tramadol by the FDA has not been achieved. In addition, royalty payments ranging from high single digit to low double digits are due on net sales of the approved product. No expense was recorded in connection with this agreement in 2020. For the year ended December 31, 2019, Avenue recorded $1.0 million in connection with the filing of its NDA for IV Tramadol. Baergic AstraZeneca AB License Agreement On December 17, 2019, Baergic entered into two license agreements: (i) a License Agreement (the “AZ License”) with AstraZeneca AB (“AZ”) to acquire an exclusive license to patent and related intellectual property rights pertaining to their proprietary compound Gamma-aminobutyric acid receptor A alpha 2 & 3 (GABAA α2,3) positive allosteric modulators (collectively, the “AZ IP”); and (ii) an Exclusive License Agreement (the “Cincinnati License”) with Cincinnati Children’s Hospital Medical Center (“Cincinnati”) to acquire patent and related intellectual property rights pertaining to a GABA inhibitor program for neurological disorders (the “Cincinnati IP”). Pursuant to the terms of the AZ License, Baergic paid an upfront fee of $3.0 million and issued 2,492,192 common shares equal to 19.95% of Baergic to AZ as consideration for AZ License. In connection with the issuance of the shares, Baergic also provided AZ with anti-dilution protection up to $75 million. Baergic valued the stock grant to AZ utilizing a discounted cash flow model to determine the weighted market value of invested capital, discounted by a lack of marketability of 44.6%, weighted average cost of capital of 20.5%, and net of debt utilized, resulting in a value of $0.029 per share or $0.1 million on December 31, 2019. Development milestone payments totaling approximately $75 million in the aggregate are due upon achievement of each milestone. Three net sales milestones totaling $130 million are due on licensed products as are high single digit royalties due on aggregate, annual, worldwide net sales of licensed products. For the years ended December 31, 2020 and 2019, Baergic recorded expense of approximately $9,000 and nil, respectively, in connection with its licenses with AZ. Cincinnati Children’s License Agreement Pursuant to the terms of the Cincinnati License, Baergic paid an upfront fee of $0.2 million as well as $30,000 for reimbursement of past patent expenses and issued 624,922 common shares equal to 5% of Baergic to Cincinnati as consideration for the license. In connection with the issuance of the shares, Baergic also provided Cincinnati with anti-dilution protection up to $15.0 million. Baergic valued the stock grant to Cincinnati utilizing a discounted cash flow model to determine the weighted market value of invested capital, discounted by a lack of marketability of 44.6%, weighted average cost of capital of 20.5%, and net of debt utilized, resulting in a value of $0.029 per share or $0.1 million on December 31, 2019. Two development milestone payments of approximately $6.5 million are payable upon milestone achievements. Four net sales milestones totaling $21.0 million are due on licensed products as are low single digit royalties due on aggregate, annual, worldwide net sales of licensed products. For the years ended December 31, 2020 and 2019, Baergic recorded expense of approximately $2,000 and nil, respectively, in connection with its Cincinnati License. Cellvation University of Texas Health Science Center at Houston License Agreement In October 2016, Cellvation entered into a license agreement with the University of Texas Health Science Center at Houston (“University of Texas”) for the treatment of traumatic brain injury using Autologous Bone Marrow Mononuclear Cells (the “Initial TBI License”) for an upfront cash fee of approximately $0.3 million and the issuance of 500,000 common shares representing 5% of the outstanding shares of Cellvation. An additional 9 development milestones approximating $6.2 million are due in connection with the development of adult indications, and an additional 8 development milestones approximating $6.0 million are due in connection with the development of pediatric indications, as well as single digit royalty net sales and royalty milestones are due for the term of the contract. An additional minimum annual royalty ranging from $50,000 to $0.2 million is due, depending on the age of the license. In addition, Cellvation entered into a secondary license with the University of Texas for a method and apparatus for conditioning cell populations for cell therapies (the “Second TBI License”). Cellvation paid an upfront fee of $50,000 in connection with the Second TBI License, and a minimum annual royalty of $0.1 million is payable beginning in the year after first commercial sale occurs (which minimum annual royalty is creditable against actual royalties paid under the Second TBI License). Additional payments of $0.3 million are due for the completion of certain development milestones and single digit royalties upon the achievement of net sales. In connection with the two University of Texas licenses, Cellvation granted each of two University of Texas researchers acting as consultants to Cellvation 500,000 shares of Cellvation common stock. For the years ended December 31, 2020 and 2019, Cellvation recorded expense of approximately $1,000 and nil, respectively, in connection with its licenses with the University of Texas. Checkpoint Dana-Farber Cancer Institute License Agreement In March 2015, Checkpoint entered into an exclusive license agreement with Dana-Farber Cancer Institute (“Dana-Farber”) to develop a portfolio of fully human immuno-oncology targeted antibodies. The portfolio of antibodies licensed from Dana-Farber include antibodies targeting PD-L1, GITR and CAIX. Under the terms of the agreement, Checkpoint paid Dana-Farber an up-front licensing fee of $1.0 million in 2015 and, on May 11, 2015, granted Dana-Farber 500,000 shares of Checkpoint common stock, valued at $32,500 or $0.065 per share. The agreement included an anti-dilution clause that maintained Dana-Farber’s ownership at 5% until such time that Checkpoint raised $10.0 million in cash in exchange for common shares. Pursuant to this provision, on September 30, 2015, Checkpoint granted to Dana-Farber an additional 136,830 shares of common stock valued at approximately $0.6 million and the anti-dilution clause thereafter expired. Dana-Farber is eligible to receive payments of up to an aggregate of approximately $21.5 million for each licensed product upon Checkpoint’s successful achievement of certain clinical development, regulatory and first commercial sale milestones. In addition, Dana-Farber is eligible to receive up to an aggregate of $60.0 million upon Checkpoint’s successful achievement of certain sales milestones based on aggregate net sales, in addition to royalty payments based on a tiered low to mid-single digit percentage of net sales. Dana-Farber receives an annual license maintenance fee of $50,000, which is creditable against future milestone payments or royalties. The portfolio of antibodies licensed from Dana-Farber include antibodies targeting PD-L1, GITR and CAIX. In connection with the license agreement with Dana-Farber, Checkpoint entered into a collaboration agreement with TGTX, which was amended and restated in June 2019, to develop and commercialize the anti-PD-L1 and anti-GITR antibody research programs in the field of hematological malignancies, while Checkpoint retains the right to develop and commercialize these antibodies in the field of solid tumors. Michael Weiss, Chairman of the Board of Directors of Checkpoint is also the Executive Chairman, President and Chief Executive Officer and a stockholder of TGTX. Under the terms of the original agreement, TGTX paid Checkpoint $0.5 million, representing an upfront licensing fee. Upon the signing of the amended and restated collaboration agreement in June 2019, TGTX paid Checkpoint an additional $1.0 million upfront licensing fee. Checkpoint is eligible to receive substantive potential milestone payments for the anti-PD-L1 program of up to an aggregate of approximately $27.6 million upon TGTX’s successful achievement of certain clinical development, regulatory and first commercial sale milestones. This is comprised of up to approximately $8.4 million upon TGTX's successful completion of clinical development milestones, and up to approximately $19.2 million upon regulatory filings and first commercial sales in specified territories. Checkpoint is also eligible to receive substantive potential milestone payments for the anti-GITR antibody program of up to an aggregate of approximately $21.5 million upon TGTX's successful achievement of certain clinical development, regulatory and first commercial sale milestones. This is comprised of up to approximately $7.0 million upon TGTX’s successful completion of clinical development milestones, and up to approximately $14.5 million upon first commercial sales in specified territories. In addition, Checkpoint is eligible to receive up to an aggregate of $60.0 million upon TGTX’s successful achievement of certain sales milestones based on aggregate net sales for both programs, in addition to royalty payments based on a tiered low double-digit percentage of net sales. Checkpoint also receives an annual license maintenance fee, which is creditable against future milestone payments or royalties. TGTX also pays Checkpoint for its out-of-pocket costs of material used by TGTX for their development activities. For the years ended December 31, 2020 and 2019, Checkpoint recognized approximately $1.0 million and $1.6 million, respectively, in revenue related to the collaboration agreement in the Consolidated Statements of Operations. The revenue for the year ended December 31, 2020 included a milestone of $925,000 upon the 12 th patient dosed in a phase 1 clinical trial for the anti-PD-L1 antibody cosibelimab during March 2020. ​ Adimab, LLC Collaboration Agreement In October 2015, Fortress entered into a collaboration agreement with Adimab to discover and optimize antibodies using their proprietary core technology platform. Under this agreement, Adimab optimized cosibelimab, Checkpoint's anti-PD-L1 antibody which it originally licensed from Dana-Farber. In January 2019, Fortress transferred the rights to the optimized antibody to Checkpoint, and Checkpoint entered into a collaboration agreement directly with Adimab on the same day. Under the terms of the agreement, Adimab is eligible to receive payments up to an aggregate of approximately $7.1 million upon the Checkpoint's successful achievement of certain clinical development and regulatory milestones, of which $4.8 million are due upon various filings for regulatory approvals to commercialize the product. In addition, Adimab is eligible to receive royalty payments based on a tiered low single digit percentage of net sales. NeuPharma, Inc. License Agreement In March 2015, the Company entered into an exclusive license agreement with NeuPharma, Inc. (“NeuPharma”) to develop and commercialize novel irreversible, 3rd generation epidermal growth factor receptor (“EGFR”) inhibitors including CK-101, on a worldwide basis (other than certain Asian countries). On the same date, the Company assigned all of its right and interest in the EGFR inhibitors to Checkpoint. Under the terms of the agreement, Checkpoint paid NeuPharma an up-front licensing fee of $1.0 million in 2015, and NeuPharma is eligible to receive payments of up to an aggregate of approximately $40.0 million upon Checkpoint’s successful achievement of certain clinical development and regulatory milestones in up to three indications, of which $22.5 million are due upon various regulatory approvals to commercialize the products. In addition, NeuPharma is eligible to receive payments of up to an aggregate of $40 million upon Checkpoint’s successful achievement of certain sales milestones based on aggregate net sales, in addition to royalty payments based on a tiered mid to high-single digit percentage of net sales. Jubilant Biosys Limited License Agreement In May 2016, Checkpoint entered into a license agreement with Jubilant Biosys Limited (“Jubilant”), whereby Checkpoint obtained an exclusive, worldwide license (the “Jubilant License”) to Jubilant’s family of patents covering compounds that inhibit BRD4, a member of the BET domain for cancer treatment, including CK-103. Under the terms of the Jubilant License, Checkpoint paid Jubilant an up-front licensing fee of $2.0 million, and Jubilant is eligible to receive payments up to an aggregate of approximately $89.0 million upon Checkpoint’s successful achievement of certain preclinical, clinical development, and regulatory milestones, of which $59.5 million are due upon various regulatory approvals to commercialize the products. In addition, Jubilant is eligible to receive payments up to an aggregate of $89.0 million upon Checkpoint’s successful achievement of certain sales milestones based on aggregate net sales, in addition to royalty payments based on a tiered low to mid-single digit percentage of net sales. In connection with the Jubilant License, Checkpoint entered into a sublicense agreement with TGTX (the “Sublicense Agreement”), a related party, to develop and commercialize the compounds licensed in the field of hematological malignancies, with Checkpoint retaining the right to develop and commercialize these compounds in the field of solid tumors. Under the terms of the Sublicense Agreement, TGTX paid Checkpoint $1.0 million, representing an upfront licensing fee, recorded as collaboration revenue – related party and Checkpoint is eligible to receive substantive potential milestone payments up to an aggregate of approximately $87.2 million upon TGTX’s successful achievement of clinical development and regulatory milestones. Such potential milestone payments may approximate $25.5 million upon TGTX’s successful completion of three clinical development milestones for two licensed products, and up to approximately $61.7 million upon the achievement of five regulatory approvals and first commercial sales in specified territories for two licensed products. In addition, Checkpoint is eligible to receive potential milestone payments up to an aggregate of $89.0 million upon TGTX’s successful achievement of three sales milestones based on aggregate net sales by TGTX, for two licensed products, in addition to royalty payments based on a mid-single digit percentage of net sales by TGTX. TGTX also pays Checkpoint for 50% of IND enabling costs and patent expenses. Checkpoint recognized $0.1 million and $0.1 million in revenue related to this arrangement during the year ended December 31, 2020 and 2019, respectively. ​ The collaborations with TGTX each contain single material performance obligations under Topic 606, which is the granting of a license that is functional intellectual property. Checkpoint's performance obligation was satisfied at the point in time when TGTX had the ability to use and benefit from the right to use the intellectual property. The performance obligations of the original agreements were satisfied prior to the adoption of Topic 606. The performance obligation of the amendment to the collaboration agreement was satisfied in June 2019. The milestone payments are based on successful achievement of clinical development, regulatory, and sales milestones. Because these payments are contingent on the occurrence of a future event, they represent variable consideration and are constrained and included in the transaction price only when it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The sales-based royalty payments are recognized as revenue when the subsequent sales occur. Checkpoint also receives variable consideration for certain research and development, out-of-pocket material costs and patent maintenance related activities that are dependent upon the Company's actual expenditures under the collaborations and are constrained and included in the transaction price only when it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. Revenue is recognized approximately when the amounts become due because it relates to an already satisfied performance obligation. For the year ended December 31, 2020, Checkpoint recognized the achievement of a clinical development milestone under its collaboration agreement with TGTX based upon their dosing of a 12th patient in a phase 1 clinical trial of cosibelimab. For the year ended December 31, 2019, Checkpoint did not receive any milestone or royalty payments. Cyprium License Agreement with the Eunice Kennedy Shriver National Institute of Child Health and Human Development In March 2017, Cyprium and the Eunice Kennedy Shriver . Helocyte License Agreement with the City of Hope Helocyte entered into the original license agreement with City of Hope National Medical Center (“COH”) on March 31, 2015, to secure: (i) an exclusive worldwide license for two immunotherapies for Cytomegalovirus (“CMV”) control in the post-transplant setting (known as Triplex and PepVax). In consideration for the license and option, Helocyte made an upfront payment of $0.2 million. In March 2016, Helocyte entered into amended and restated license agreements for each of its PepVax and Triplex immunotherapies programs with its licensor COH. The amended and restated licenses expand the intellectual property and other rights granted to Helocyte by COH in the original license agreement without modifying the financial terms. In 2018, Helocyte discontinued the development of PepVax and terminated the related license and clinical trial agreements with COH. ​ If Helocyte successfully develops and commercializes Triplex, COH is eligible to receive up to $3.7 million related to three financial milestones, $7.5 million in development milestones for the remaining two development milestones and up to $26.0 million in three milestones related to net sales for each licensed product. To date Helocyte has completed a Phase 2 clinical trial program for Triplex. In April 2015, Helocyte secured the exclusive worldwide rights to an immunotherapy for the prevention of congenital CMV: ConVax (formerly Pentamer) from COH for an upfront payment of $45,000. If Helocyte successfully develops and commercializes Pentamer, COH could receive up to $5.5 million for the achievement of four development milestones, $26.0 million for three sales milestones, single digit royalties based on net sales reduced by certain factors and a minimum annual royalty of $0.75 million per year following a first marketing approval. For the year ended December 31, 2020 and 2019, Helocyte recorded nil and nil respectively in research and development - licenses acquired on the Consolidated Statement of Operations in connection with this license. License with the National Institute of Allergy and Infectious Disease (NIAD) In December 2019, Helocyte entered into a non-exclusive license agreement with the National Institute of Allergy and Infectious Disease (a division of the National Institutes of Health (“NIAID”)) for the use of certain material pertaining to one of its product candidates. Helocyte agreed to pay an upfront fee of $0.5 million, which is payable in three separate installments, as well as a minimum annual royalty of $55,000. Additional payments of up to $1,050,000 in the aggregate are due upon the achievement of four developmental milestones, and royalties in the low single digits are due on net sales of licensed products. For the year ended December 31, 2020 and 2019, Helocyte recorded nil and $0.5 million, respectively, in research and development - licenses acquired on the Consolidated Statement of Operations in connection with this license. Mustang For the years ended December 31, 2020 and 2019 Mustang recorded the following expense in research and development – licenses acquired: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 City of Hope National Medical Center ​ ​ ​ ​ ​ ​ CD123 (MB-102) 3 ​ $ 334 ​ $ 250 IL13Rα2 (MB-101) 3 ​ ​ 334 ​ ​ — HER2 (MB-103) 1 ​ ​ 500 ​ ​ — CS1 (MB-104) ​ ​ 200 ​ ​ 200 PSCA (MB-105) 3 ​ 200 ​ 200 Spacer ​ ​ 334 ​ ​ — Fred Hutch - CD20 (MB-106) 2 ​ ​ 300 ​ ​ — Nationwide Children’s Hospital - C134 (MB-108) ​ ​ — ​ ​ 200 CSL Behring (Calimmune) ​ ​ 170 ​ ​ 200 UCLA ​ ​ — ​ ​ 300 SIRION LentiBOOST TM ​ ​ 117 ​ ​ — Total ​ $ 2,489 ​ $ 1,350 ​ License Agreement with City of Hope In March 2015, Mustang entered into an exclusive license agreement with COH to acquire intellectual property rights pertaining to chimeric antigen receptor (“CAR”) engineered T cell (“CAR T”) technologies (the “COH License”). Pursuant to the COH License, Mustang paid COH an upfront fee of $2.0 million in April 2015 (included in research and development-licenses acquired expenses In February 2017, the Company and COH amended and restated the COH License by entering into three separate amended and restated exclusive license agreements, one relating to CD123 (MB-102), one relating to IL13Rα2 (MB-101) and one relating to the Spacer technology, that amended the COH License in certain other respects, and collectively replace the COH License in its entirety. The total potential consideration payable to COH by the Company, in equity or cash, did not, in the aggregate, change materially from the COH License. CD123 License with City of Hope (MB-102) Pursuant to the CD123 License, Mustang and COH acknowledge that an upfront fee was paid under the COH License. In addition, an annual maintenance fee will continue to apply. COH is eligible to receive up to approximately $14.5 million in milestone payments upon and subject to the achievement of certain milestones. Royalty payments in the mid-single digits are due on net sales of licensed products. Mustang is obligated to pay COH a percentage of certain revenues received in connection with a sublicense in the mid-teens to mid-thirties, depending on the timing of the sublicense in the development of any product. In addition, equity grants made under the COH License were acknowledged, and the anti-dilution provisions of the COH License were carried forward. For the year ended December 31, 2020, Mustang expensed a non-refundable milestone payment of $0.3 million in connection with their public underwritten offerings. For the year ended December 31, 2019, Mustang expensed a non-refundable milestone payment of $0.3 million upon the twelfth patient dosed in a Phase 1 clinical study of CD123. Nationwide Children’s Hospital License Agreement (MB-108) In February 2019, Mustang announced that it partnered and entered into an exclusive worldwide license agreement with Nationwide Children’s Hospital (“Nationwide”) to develop their C134 oncolytic virus (MB-108) for the treatment of glioblastoma multiforme (“GBM”). Mustang intends to combine MB-108 with MB-101 (IL13Rα2-specific CAR T) to potentially enhance efficacy in treating GBM. There were no expenses recorded in 2020 in connection with this license. For the year ended December 31, 2019, Mustang paid $0.2 million in consideration for the license to exclusive, worldwide rights to develop and commercialize products that incorporate data, know-how and/or patents related to MB-108 that were developed at Nationwide. Additional payments are due to Nationwide upon achievement of development and commercialization milestones totaling $152.8 million. Royalty payments in the low-single digits are due on net sales of licensed products. CS1 License with City of Hope (MB-104) On May 31, 2017, Mustang entered into an exclusive license agreement with the COH for the use of CS1-specific CAR T technology to be directed against multiple myeloma. Pursuant to the agreement, Mustang paid an upfront fee of $0.6 million on July 3, 2017, and owes an annual maintenance fee of $50,000, which began in 2019. Additional payments of up to $14.9 million are due upon and subject to the achievement of ten development milestones, and royalty payments in the mid-single digits are due on net sales of licensed products. During the year ended December 31, 2020, Mustang expensed a non-refundable milestone payment of $0.2 million in connection with this license for the issuance of the first patent related to the CS1 technology. During the year ended December 31, 2019, Mustang expensed a non-refundable milestone payment of $0.2 million upon the first patient dosed in a Phase 1 clinical study of the CS1 CAR T. PSCA License with City of Hope (MB-105) On May 31, 2017, Mustang entered into an exclusive license agreement with the COH for the use of prostate stem cell antigen (“PSCA”) CAR T technology to be used in the treatment of prostate cancer. Pursuant to the agreement, Mustang paid an upfront fee of $0.3 million on July 3, 2017, and owes an annual maintenance fee of $50,000, which began in 2019. Additional payments of up to $14.9 million are due upon and subject to the achievement of ten development milestones, and royalty payments in the mid-single digits are due on net sales of licensed products. During the years ended December 31, 2020 and 2019, Mustang recorded an expense of $0.2 million and nil, respectively, in connection with the acquisition of this license. CSL Behring (Calimmune) License (MB-107) On August 23, 2019, Mustang entered into a non-exclusive license agreement with CSL Behring (Calimmune, Inc.) (“Calimmune License”) for the Cytegrity TM University of California License On March 17, 2017, Mustang entered into an exclusive license agreement with the Regents of the University of California (“UCLA License”) to acquire intellectual property rights in patent applications related to the engineered anti-prostate stem cell antigen antibodies for cancer targeting and detection. Pursuant to the UCLA License, Mustang paid UCLA an upfront fee of $0.2 million on April 25, 2017. Annual maintenance fees also apply; additional payments are due upon achievement of certain development milestones totaling $14.3 million, and royalty payments in the mid-single digits are due on net sales of licensed products. In September 2019, COH commenced its Phase 1 clinical trial resulting in the achievement of a development milestone, and as a result Mustang recorded an expense of $0.3 million. There were no expenses recorded in 2020 in connection with this license. HER2 License with City of Hope (MB-103) On May 31, 2017, Mustang entered into an exclusive license agreement with the COH for the use of human epidermal growth factor receptor 2 (“HER2”) CAR T technology (“HER2 Technology”), which will be applied in the treatment of glioblastoma multiforme. Pursuant to the agreement, Mustang paid an upfront fee of $0.6 million and owes an annual maintenance fee of $50,000, which began in 2019. Additional payments of up to $14.9 million are due upon and subject to the achievement of ten development milestones, and royalty payments in the mid-single digits are due on net sales of licensed products. During the year ended December 31, 2020, Mustang recorded a non-refundable milestone payment of $0.5 million in connection with the twelfth patient treated in the Phase 1 clinical study of HER2 CAR T technology at COH. For the year ended December 31, 2019, Mustang expensed a non-refundable milestone payment of $0.2 million upon the first patient dosed in the Phase 1 clinical study of HER2. St. Jude Children’s Research Hospital License (MB-107 and MB-207) On August 2, 2018, Mustang entered into an exclusive worldwide license agreement with St. Jude for the development of a first-in-class ex vivo Manufacturing License with City of Hope On January 3, 2018, Mustang entered into a non-exclusive license agreement with COH to acquire patent and licensed know-how rights related to developing, manufacturing, and commercializing licensed products. The Company paid $0.1 million in consideration for the licenses to the patent rights and the licensed know-how in addition to an annual maintenance fee. Royalty payments in the low-single digits are due on net sales of licensed products. During the years ended December 31, 2020 and 2019, respectively, Mustang recorded no expense in connection with the COH license. IL13Rα2 License with City of Hope (MB-101) Pursuant to the IL13Rα2 License, Mustang and COH acknowledge that an upfront fee was paid under the Original License. In addition, an annual maintenance fee will continue to apply. COH is eligible to receive up to approximately $14.5 million in milestone payments upon and subject to the achievement of certain milestones. Royalty payments in the mid-single digits are due on net sales of licensed products. Mustang is obligated to pay COH a percentage of certain revenues received in connection with a sublicense in the mid-teens to mid-thirties, depending on the timing of the sublicense in the development of any product. In addition, equity grants made under the Original License were acknowledged, and the anti-dilution provisions of the Original License were carried forward. For the year ended, December 31, 2020, Mustang expensed a non-refundable milestone payment of $0.3 million in connection with their public underwritten offerings. There was no expense recorded for the year ended December 31, 2019. Spacer License with City of Hope Pursuant to the Spacer License, Mustang and COH acknowledge that an upfront fee was paid under the Original License. In addition, an annual maintenance fee will continue to apply. No royalties are due if the Spacer technology is used in conjunction with a CD123 CAR or an IL13Rα2 CAR, and royalty payments in the low single digits are due on net sales of licensed products if the Spacer technology is used in conjunction with other intellectual property. Mustang is obligated to pay COH a percentage (in the mid-thirties) of certain revenues received in connection with a sublicense. In addition, equity grants made under the Original License were acknowledged, and the anti-dilution provisions of the Original License were carried forward. For the year ended December 31, 2020, Mustang expensed a non-refundable milestone payment of $0.3 million in connection with their public underwritten offerings. There was no expense recorded for the year ended December 31, 2019. IV/ICV Agreement with City of Hope On February 17, 2017, Mustang entered into an exclusive license agreement (the “IV/ICV Agreement”) with COH to acquire intellectual property rights in patent applications related to the intraventricular and intracerebroventricular methods of delivering T cells that express CARs. Pursuant to the IV/ICV Agreement, Mustang paid COH an upfront fee of $0.1 million in March 2017. COH is eligible to recei

Sponsored Research and Clinical

Sponsored Research and Clinical Trial Agreements	12 Months Ended
	Dec. 31, 2020
Sponsored Research and Clinical Trial Agreements
Sponsored Research and Clinical Trial Agreements	8. Sponsored Research and Clinical Trial Agreements Aevitas ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 UMass - adeno-associated virus ("AAV") ​ $ 381 ​ $ — UPenn - AAV ​ ​ 567 ​ ​ 1,067 Duke - AAV ​ ​ — ​ ​ 66 Total ​ $ 948 ​ $ 1,133 ​ On January 25, 2018, Aevitas entered into a Sponsored Research Agreement with the University of Massachusetts (“UMass SRA”) for certain continued research and development activities related to the development of adeno-associated virus (“AAV”) gene therapies in complement-mediated diseases. The total amount to be funded by Aevitas under the UMass SRA is $0.8 million. Pursuant to the terms of the UMass SRA, Aevitas paid $0.8 million which was due upon execution. On May 31, 2020, a First Amendment to the UMass SRA was signed and the total amount to be funded was $0.7 million, including $0.4 million due within 30 days of execution. For the years ended December 31, 2020 and 2019, Aevitas recorded expense of approximately $0.4 million and nil, respectively, in connection with the UMass SRA. The expense was recorded in research and development expenses in the Company’s Consolidated Statement of Operations. On July 24, 2018, Aevitas entered into a Sponsored Research Agreement with the Trustees of the University of Pennsylvania (“UPenn SRA”) for certain continued research and development activities related to the development of AAV gene therapies in complement-mediated diseases. The total amount to be funded by Aevitas under the UPenn SRA is $2.0 million. Pursuant to the terms of the UPenn SRA, Aevitas paid $0.3 million which was due upon execution. For the years ended December 31, 2020 and 2019, Aevitas recorded expense of approximately $0.6 million and $1.1 million, respectively, in connection with the UPenn SRA. The expense was recorded in research and development expenses in the Company’s Consolidated Statement of Operations. On September 1, 2019, Aevitas entered into a Sponsored Research Arrangement (“SRA”) with Duke University School of Medicine (“Duke”). For the years ended December 31, 2020 and 2019, Aevitas recorded approximately nil and $0.1 million, respectively, for the purpose of conducting a study to identify a dose range for AAV8 vectors in Dry Age-related Macular Degeneration (“Dry AMD”) in research and development expense on the Consolidated Statement of Operations. Cellvation In October 2016, Cellvation entered research funding agreement with the University of Texas in connection with the license for a method and apparatus for conditioning cell populations for cell therapies. In connection with this agreement Cellvation agreed to fund $0.8 million of research quarterly through March 31, 2018. The agreement was revised effective May 1, 2017, with quarterly payments extended through December 31, 2018. For the years ended December 31, 2020 and 2019, Cellvation recorded an expense of nil and $0.1 million, respectively, representing amounts due under this arrangement. Mustang For the years ended December 31, 2020 and 2019 Mustang recorded the following expense in research and development for sponsored research and clinical trial agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 City of Hope National Medical Center ​ $ 500 ​ $ 2,000 CD123 (MB-102) ​ 433 ​ 1,202 IL13Rα2 (MB-101) ​ 530 ​ 876 Manufacturing ​ — ​ 457 CS1 (MB-104) ​ ​ 885 ​ ​ — HER2 (MB-103) ​ ​ 1,519 ​ ​ — PSCA (MB-105) ​ ​ 204 ​ ​ — Beth Israel Deaconess Medical Center - CRISPR ​ ​ — ​ ​ 69 St. Jude Children's Research Hospital - XSCID (MB-107) ​ ​ 1,842 ​ ​ 777 Fred Hutchinson Cancer Research Center - CD20 (MB-106) ​ ​ 1,804 ​ ​ 762 Total ​ $ 7,717 ​ $ 6,143 ​ City of Hope Sponsored Research Agreement In March 2015, in connection with Mustang’s license with COH for the development of CAR T, Mustang entered into a Sponsored Research Agreement in which Mustang will fund continued research in the amount of $2.0 million per year, payable in four equal annual installments, until 2020. The research covered under this arrangement is for IL13Rα2 (MB-101), CD123 (MB-102) and the Spacer technology. For the years ended December 31, 2020 and 2019, Mustang incurred expense of $0.5 million and $2.0 million, respectively and recorded as research and development expense in the Company’s Consolidated Statement of Operations. CD123 (MB-102) Clinical Research Support Agreement On February 17, 2017, Mustang entered into a Clinical Research Support Agreement for CD123. Pursuant to the terms of this agreement, Mustang made an upfront payment of approximately $20,000 and will contribute an additional $0.1 million per patient in connection with the on-going investigator-initiated study. Further, Mustang agreed to fund approximately $0.2 million over three years pertaining to the clinical development of CD123. For the years ended December 31, 2020 and 2019, Mustang recorded approximately $0.4 million and $1.2 million, respectively, in research and development expenses in the Company’s Consolidated Statements of Operations. CS1(MB-104) Clinical Research Support Agreement In June 2020, Mustang entered into a clinical research and support agreement with COH in connection with an Investigator-sponsored study conducted under an Institutional Review Board-approved, investigator-initiated protocol entitled: "Phase I Study to Evaluate Cellular Immunotherapy Using Memory-Enriched T Cells Lentivirally Transduced to Express a CS1-Targeting, Hinge-Optimized, 41BB-Costimulatory Chimeric Antigen Receptor and a Truncated EGFR Following Lymphodepleting Chemotherapy in Adult Patients with CS1+ Multiple Myeloma." The CAR T being studied under this protocol has been designated by Mustang as MB-104. Under the terms of the agreement Mustang will reimburse COH for costs associated with this trial not to exceed $2.4 million. The agreement will expire upon the delivery of the final study report or earlier. During the year ended December 31, 2020, Mustang recorded approximately $0.9 million in research and development expenses in the Company’s Consolidated Statement of Operations pursuant to this agreement. IL13Rα2 (MB-101) Clinical Research Support Agreements On February 17, 2017, Mustang entered into a Clinical Research Support Agreement for IL13Rα2 (the “IL13Rα2 GBM CRA”). Pursuant to the terms of this agreement Mustang made an upfront payment of approximately $9,300 and will contribute an additional $0.1 million per patient in connection with the on-going investigator-initiated study. Further, Mustang agreed to fund approximately $0.2 million over three years pertaining to the clinical development of IL13Rα2. In October 2020, Mustang entered into a Clinical Research Support Agreement for the IL13Rα2 directed CAR T program for adult patients with Leptomeningeal Glioblastoma, Ependymoma or Medulloblastoma (the “IL13Rα2 Leptomeningeal CRA”). Pursuant to the terms of the IL13Rα2 Leptomeningeal CRA, Mustang made an upfront payment of $29,375 and will contribute an additional $0.1 million per patient in connection with the on-going investigator-initiated study. Further, the Company agreed to fund approximately $0.2 million annually pertaining to the clinical development of IL13Rα2. For the years ended December 31, 2020 and 2019, Mustang recorded approximately $0.5 million and $0.9 million, respectively, in research and development expenses under the IL13Rα2 CRAs in the Company’s Consolidated Statement of Operations. HER2 (MB-103) Clinical Research Support Agreement In September 2020, Mustang entered into a clinical research support agreement with COH in connection with an Investigator-sponsored study conducted under an Institutional Review Board-approved, investigator-initiated protocol entitled: “Phase I Study of Cellular Immunotherapy using Memory-Enriched T Cells Lentivirally Transduced to Express a HER2-Specific, Hinge-Optimized, 41BB-Costimulatory Chimeric Receptor and a Truncated CD19 for Patients with Recurrent/Refractory Malignant Glioma.” The CAR T being studied under this protocol has been designated as MB-103. Under the terms of the agreement Mustang will pay COH $29,375 upon execution and will reimburse COH for costs associated with this trial not to exceed $3.0 million. The agreement will expire upon the delivery of a final study report or earlier. For the year ended December 31, 2020, Mustang recorded $1.5 million in research and development expenses in the Company’s Consolidated Statement of Operations pursuant to this agreement. PSCA (MB-105) Clinical Research Support Agreement In October 2020, Mustang entered into a clinical research support agreement with COH in connection with an Investigator-sponsored study conducted under an Institutional Review Board-approved, investigator-initiated protocol entitled: “A Phase 1b study to evaluate PSCA-specific chimeric antigen receptor (CAR)-T cells for patients with metastatic castration resistant prostate cancer.” The CAR T being studied under this protocol has been designated as MB-105. Under the terms of the agreement Mustang will pay COH $33,000 upon execution and will reimburse COH for costs associated with this trial not to exceed $2.3 million. The agreement will expire upon the delivery of a final study report or earlier. For the year ended December 31, 2020, Mustang recorded $0.2 million in research and development expenses in the Company’s Consolidated Statement of Operations pursuant to this agreement. City of Hope Sponsored Research Agreement - Manufacturing On January 3, 2018, Mustang entered into a Sponsored Research Agreement (“SRA”) with COH to optimize and develop CAR T cell processing procedures. Pursuant to the SRA, Mustang funded continued research in the amount of $0.9 million for the program, with an initial term of two CRISPR Sponsored Research Agreement with Beth Israel Deaconess Medical Center, Inc. On November 28, 2017, Mustang entered into a Sponsored Research Agreement with Beth Israel Deaconess Medical Center Inc. (“BIDMC”) to perform research relating to gene editing, via the use of CRISPR/Cas9, to be used in enhancing the efficacy of CAR T cell therapies for solid tumor indications and to generate universal off the shelf CAR T cell therapies for both liquid and solid tumor indications. Mustang agreed to fund approximately $0.8 million over a three-year period. Mustang recorded nil and $0.1 million in 2020 and 2019, respectively, related to this agreement in research and development expenses in the Company’s Consolidated Statements of Operations. In January 2019, Mustang terminated the SRA with BIDMC due to the departure of key personnel from BIDMC. CD20 (MB-106) Clinical Trial Agreement with Fred Hutch On July 3, 2017, in conjunction with the CD20 Technology License from Fred Hutch, Mustang entered into an investigator-initiated clinical trial agreement (“CD20 CTA”) to provide partial funding for a Phase 1/2 clinical trial at Fred Hutch evaluating the safety and efficacy of the CD20 Technology in patients with relapsed or refractory B-cell non-Hodgkin lymphomas. In connection with the CD20 CTA, Mustang agreed to fund up to $5.3 million of costs associated with the clinical trial, which commenced during the fourth quarter of 2017. In November 2020, the CD20 CTA was amended to include additional funding of approximately $0.8 million for the treatment of five patients with chronic lymphocytic leukemia. For the years ended December 31, 2020 and 2019 Mustang recorded $1.8 million and $0.6 million of expense, respectively, related to this agreement in research and development expenses in the Company’s Consolidated Statements of Operations. CD20 (MB-106) Sponsored Research Agreement – Manufacturing with Fred Hutch On March 17, 2018, Mustang entered into a Sponsored Research Agreement (“SRA”) with Fred Hutch related to developing and optimizing processes and systems associated with CD20 cell processing. Pursuant to the SRA, Mustang funded research in the amount of $0.6 million during the term of the SRA, which expired in March 2019. For the years ended December 31, 2020 and 2019, Mustang recorded expense of nil and $0.2 million, respectively, in research and development expenses in the Statements of Operations pursuant to the terms of this agreement. XSCID (MB-107) Data Transfer Agreement with St. Jude In June 2020, Mustang entered into a Data Transfer Agreement with St. Jude under which Mustang will reimburse St. Jude for costs associated with St. Jude’s clinical trial for the treatment of infants with XSCID. Pursuant to the terms of this agreement and for the year ended December 31, 2020, Mustang paid an upfront fee of $1.1 million, which was recorded in research and development expenses in the Company’s Consolidated Statement of Operations. Mustang will continue to reimburse St. Jude for costs incurred in connection with this trial. MB-107 (XSCID) Non-Interventional Services Agreement with Children’s CGMP In December 2019, Mustang entered into a Non-Interventional Services Agreement with Children's CGMP, LLC ("Children’s"), an affiliate of St. Jude Children's Research Hospital, pursuant to which Children’s provides lentiviral vector for non-clinical XSCID research purposes, as well as related advisory services. Mustang agreed to fund approximately $0.8 million upon execution of the agreement, which was recorded in research and development expenses for the year ended December 31, 2019 in the Company's Consolidated Statement of Operations. Oncogenuity Columbia Sponsored Research Agreement Pursuant to the terms of the Columbia License, Oncogenuity will make semi-annual research payments to Columbia over a five year period ending in November 2024; such payments not to exceed $4.8 million. For the year ended December 31, 2020, Oncogenuity recorded expense of $0.5 million in research and development in the Company’s Consolidated Statements of Operations. No expense was recorded in 2019. University of Oxford Sponsorship Agreement On December 16, 2020 Oncogenuity entered into an agreement with The Chancellor Masters and Scholars of the University of Oxford (“Oxford”). Under the terms of the agreement Oxford will engage in preclinical development of antisense oligonulcleotides as a therapy in certain indications. In connection with the agreement Oncogenuity agreed to fund research for approximately 18 months for up to of $0.6 million (£0.4 million). Oncogenuity made an up-front payment of $0.1 million (£0.1 million) in January 2021. Tamid On November 30, 2017, in connection with its three separate license agreements with UNC, Tamid entered into a Sponsored Research Agreement with UNC (“UNC SRA”) for certain continued research and development activities related to Nanodysferlin for treatment of Dysferlinopathy, and AAV-HLA-G for corneal transplant rejection. Total amount to be funded by Tamid under the UNC SRA is $2.3 million over a term of three years. Pursuant to the terms of the UNC SRA, Tamid paid $0.8 million which was due upon execution. For the years ended December 31, 2020 and 2019, Tamid recorded expense of nil and nil respectively in connection with the UNC SRA. The expense was recorded in research and development expenses in the Company’s Consolidated Statements of Operations. Effective December 2019, Tamid returned the license to UNC and ceased to incur costs associated with the development of products under this license.

Intangibles, net

Intangibles, net	12 Months Ended
	Dec. 31, 2020
Intangibles, net
Intangibles, net	9. Intangibles On December 18, 2020, Journey entered an Asset Purchase Agreement with a third party (the “Anti-itch Product Agreement”) for a topical product that is indicated to treat scabies and skin itch conditions (“Anti-itch Product”). Pursuant to the terms and conditions of the Anti-itch Product Agreement, Journey agreed to pay $4.0 million, comprised of a non-refundable deposit of $0.2 million upon the execution of the term sheet, a cash upfront payment of $1.8 million on January 1, 2021 and additional future payments of $0.5 million on April 1, 2021, $0.5 million on July 1, 2021, and $1.0 million on January 1, 2022. There are no subsequent milestone payments or royalties beyond the aforementioned payments. Commercial launch of this product is expected in the third quarter of 2021. The Company, in accordance with ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business On July 29, 2020, Journey entered into a License and Supply Agreement with a third party to acquire intellectual property rights to an oral acne product that is indicated for the treatment of severe acne (the “Isotretinoin Agreement”). Pursuant to the terms and conditions of the Isotretinoin Agreement, Journey agreed to pay $5.0 million, comprised of an upfront payment of $1.0 million paid upon execution with remaining payments due as follows: $0.5 million upon achievement of a regulatory approval milestone and $0.5 million upon the delivery of the first order and $3.0 million due in $1.0 million installments, on the 18-month anniversary, the 24-month 36-month The Company, in accordance with ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business On July 22, 2019 Journey purchased Ximino®, a minocycline hydrochloride used to treat acne from a third party. Pursuant to the terms and conditions of the Asset Purchase Agreement (“APA”), total consideration for the APA is $9.4 million, comprised of an upfront payment of $2.4 million payable within 60 days after execution on September 22, 2019. The remaining four payments totaling $7.0 million are due in consecutive years commencing on the second anniversary of execution of the APA. In addition, Journey is obligated to pay royalties in the mid-single digits based on net sales of Ximino, subject to specified reductions. The Company, in accordance with ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business Contingencies, In accordance with the terms of the APA Journey will incur interest expense in the event of payment default. As such per ASC 835-30 Interest-Imputed Interest, On August 31, 2018, JMC entered into an agreement with a third party to acquire the exclusive rights to Exelderm®, a topical antifungal available in a cream and solution. This acquisition was recorded as an intangible asset and expense will be recognized over the expected life of Exelderm® of 3 years. JMC commenced the sale of Exelderm® in September 2018 and accordingly commenced the amortization of this cost. In January 2016, JMC entered into a licensing agreement with a third party to distribute its prescription wound cream Luxamend ® and paid an upfront fee of $50,000. Additionally, in January 2016, JMC entered into a licensing agreement with a third party to distribute its prescription emollient Ceracade ® for the treatment of various types of dermatitis and paid an upfront fee of $0.3 million. JMC commenced the sale of both of these products during the year ended December 31, 2016 and accordingly commenced the amortization of these costs over their respective three year estimated useful life. In March 2015, JMC entered into a license and supply agreement to acquire the rights to distribute Targadox® a dermatological product for the treatment of acne. JMC made an upfront payment of $1.3 million. Further payments will be made based on a revenue sharing arrangement. JMC received FDA approval for the manufacturing of this product in July 2016 and commenced sales of this product in October 2016. The table below provides a summary of intangible assets as of December 31, 2020 and 2019, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated Useful ​ ​ ​ ​ ($ in thousands) Lives (Years) December 31, 2020 December 31, 2019 Total Intangible assets – asset purchases ​ 3 to 7 ​ $ 18,606 ​ $ 9,934 Accumulated amortization ​ (3,977) ​ (2,557) Net intangible assets ​ $ 14,629 ​ $ 7,377 ​ The table below provides a summary for the years ended December 31, 2020 and 2019, of recognized expense related to product licenses, which was recorded in costs of goods sold on the Consolidated Statement of Operations (see Note 19): ​ ​ ​ ​ ​ ​ ​ Intangible ($ in thousands) Assets, Net Beginning balance at December 31, 2018 ​ $ 1,417 Additions: ​ ​ ​ Purchase of Ximino 1 ​ ​ 7,134 Amortization expense ​ ​ (1,174) Beginning balance at December 31, 2019 ​ ​ 7,377 Additions: ​ ​ ​ Isotretinoin Agreement 2 ​ ​ 4,727 Anti-itch product license acquisition 3 ​ ​ 3,945 Amortization expense ​ (1,420) Ending balance at December 31, 2020 ​ $ 14,629 ​ Note 1: Includes an upfront payment of $2.4 million and four payments totaling $7.0 million due in consecutive years commencing on the second anniversary of the execution of the APA. Such payments were discounted by $2.3 million as a result of the long-term nature of such payments. Note 2: Includes an upfront payment of $1.0 million and a milestone payment of $0.5 million in 2020 and three payments totaling $3.5 million due at various points between 2021 through 2023. Such payments were discounted by $0.3 million as a result of the long-term nature of such payments. As of December 31, 2020, this asset has not yet been placed in service, therefore no amortization expense was recognized on this asset for the year ended December 31, 2020. Journey expects the asset to be placed in service in the first half of 2021. Once the asset is placed in service Journey will amortize the asset over five years, which represents its expected useful life. Note 3: Includes an upfront payment of $0.2 million and three payments totaling $2.8 million in 2021 and $1.0 million in 2022. Such payments were discounted by $0.1 million as a result of the long-term nature of such payments. As of December 31, 2020, this asset has not yet been placed in service, therefore no amortization expense was recognized on this asset for the year ended December 31, 2020. The Company expects to launch this asset in Q3 2021. Once the asset is placed in service Journey will amortize the asset over three years, which represents its expected useful life. ​ The future amortization of these intangible assets is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ($ in thousands) Ximino® Exelderm® Amortization Year Ended December 31, 2021 ​ $ 1,019 ​ $ 267 ​ $ 1,286 Year Ended December 31, 2022 ​ 1,019 ​ — ​ 1,019 Year Ended December 31, 2023 ​ ​ 1,019 ​ ​ — ​ ​ 1,019 Year Ended December 31, 2024 ​ ​ 1,019 ​ ​ — ​ ​ 1,019 Year Ended December 31, 2025 ​ 1,019 ​ — ​ 1,019 Thereafter ​ ​ 595 ​ ​ — ​ ​ 595 Sub-total ​ ​ 5,690 ​ ​ 267 ​ ​ 5,957 Intangible assets not yet placed in service ​ ​ — ​ ​ — ​ ​ 8,672 Total ​ $ 5,690 ​ $ 267 ​ $ 14,629 ​

Debt and Interest

Debt and Interest	12 Months Ended
	Dec. 31, 2020
Debt and Interest
Debt and Interest	10. Debt and Interest Debt Total debt consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ($ in thousands) ​ 2020 ​ 2019 ​ Interest rate ​ Maturity IDB Note ​ $ — ​ $ 14,929 2.25 % Aug - 2021 2017 Subordinated Note Financing 3 ​ — ​ 3,254 8.00 % March - 2022 2017 Subordinated Note Financing 3 ​ — ​ 13,893 8.00 % May - 2022 2017 Subordinated Note Financing 3 ​ — ​ 1,820 8.00 % June - 2022 2017 Subordinated Note Financing 3 ​ — ​ 3,018 8.00 % August - 2022 2017 Subordinated Note Financing 3 ​ — ​ 6,371 8.00 % September - 2022 2018 Venture Notes 4 ​ — ​ 6,517 8.00 % August - 2021 2018 Venture Notes 4 ​ — ​ 15,190 8.00 % September - 2021 2019 Notes 1 ​ — ​ 9,000 12.00 % September - 2021 Mustang Horizon Notes 2 ​ — ​ 15,750 9.00 % October - 2022 Oaktree Note ​ ​ 60,000 ​ ​ — ​ 11.00 % August - 2025 Total notes payable ​ 60,000 ​ 89,742 Less: Discount on notes payable ​ 8,323 ​ 5,086 Total notes payable ​ $ 51,677 ​ $ 84,656 ​ Note 1: Formerly the Opus Credit Facility (see Note 17). Note 2: Interest rate is 9.0% plus one-month LIBOR Rate in excess of 2.5%; at December 31, 2019, $1.2 million is included in Notes payable, short-term on the Consolidated Balance Sheet. Note 3: As a result of a one year maturity date extension, the interest rate of 9.0% takes effect in year 4 of the note. Note 4: At December 31, 2019, $6.0 million is included in Notes payable, short-term on the Consolidated Balance Sheet. ​ Oaktree Note ​ On August 27, 2020 (the “Closing Date”), Fortress, as borrower, entered into a $60.0 million senior secured credit agreement (the “Oaktree Agreement”) with Oaktree. The Company borrowed the full $60.0 million in connection with the terms of the Oaktree Note on the Closing Date and used the bulk of the proceeds to repay its outstanding debt to other lenders (2017 Subordinated Notes, 2018 Venture Notes and 2019 Notes (previously the “Opus Credit Facility”)). ​ The Oaktree Note bears interest at a fixed annual rate of 11.0%, payable quarterly and maturing on the fifth anniversary of the Closing Date, August 27, 2025, the (“Maturity Date”). The Company is required to make quarterly interest-only payments until the Maturity Date, at which point the outstanding principal amount is due. The Company may voluntarily prepay the Oaktree Note at any time subject to a Prepayment Fee. The Company is also required to make mandatory prepayments of the Oaktree Note under various circumstances. No amounts paid or prepaid may be reborrowed without Oaktree consent. ​ The Oaktree Agreement contains customary representations and warranties and customary affirmative and negative covenants, including, among other things, restrictions on indebtedness, liens, affiliate transactions, investments, acquisitions, mergers, dispositions, prepayment of permitted indebtedness, and dividends and other distributions, subject to certain exceptions. These affirmative and negative covenants apply in different instances to Fortress itself, its private subsidiaries, its public subsidiaries, or certain combinations of the foregoing. The limitations on dividends and other distributions have the practical effect of preventing any further issuances by the Company or its private subsidiaries of equity securities with cash dividends or redemption features. ​ In addition, the Oaktree Agreement contains certain financial covenants, including, among other things, (i) maintenance of minimum liquidity and (ii) a minimum revenue test that requires Journey’s annual revenue to be equal to or to exceed annual revenue projections set forth in the agreement. Failure by the Company or Journey, as applicable, to comply with the financial covenants will result in an event of default, subject to certain cure rights of the Company. The Company was in compliance with all applicable covenants under the Oaktree Note as of December 31, 2020. ​ The Oaktree Agreement contains customary events of default, in certain circumstances subject to customary cure periods. These events of default apply in different instances to Fortress itself, its private subsidiaries, its public subsidiaries, or a certain combination of the foregoing. Following an event of default and any cure period, if applicable, the Agent will have the right upon notice to accelerate all amounts outstanding under the Oaktree Agreement, in addition to other remedies available to the lenders as secured creditors of the Company. ​ The Oaktree Agreement grants a security interest in favor of the Agent, for the benefit of the lenders, in substantially all of the Company’s assets (consisting principally of the Company’s shareholdings in, and in some cases debt owing from, its partner companies) as collateral securing the Company’s obligations under the Oaktree Agreement, except for: (i) certain interests in controlled foreign corporation subsidiaries of the Company; (ii) the Company’s holdings in Avenue; and (iii) those portions of the Company’s holdings in certain subsidiaries (plus Caelum) that are encumbered by pre-existing equity pledges to certain of the Company’s officers. None of Fortress’ subsidiaries or partner companies is a party to the Oaktree Agreement, and the collateral package does not include the asets of any such subsidiaries or partner companies. ​ Pursuant to the terms of the Oaktree Agreement, on the Closing Date the Company paid Oaktree an upfront commitment fee equal to 3% of the $60.0 million, or $1.8 million. In addition, the Company paid a $35,000 Agency fee to the Agent, which was due on the Closing Date and will be due annually, together with fees of $2.5 million directly to third parties involved in the transaction. ​ In connection with the Oaktree Note, the Company issued warrants to Oaktree and certain of its affiliates to purchase up to 1,749,450 shares of common stock of the Company (see Note 14) with a relative fair value of $4.4 million. ​ As of December 31, 2020, the Company recorded the fees totaling $8.7 million ($1.8 million to Oaktree, $2.5 million of expenses paid to third-parties and $4.4 million representing the relative fair value of the Oaktree Warrants) to debt discount. These costs will be amortized over the term of the Oaktree Note. IDB Note On February 13, 2014, the Company executed a promissory note in favor of IDB in the amount of $15.0 million (the “IDB Note”). The Company borrowed $14.0 million against this note and used it to repay its prior loan from Hercules Technology Growth Capital, Inc. The Company could request revolving advances under the IDB Note in a minimum amount of $0.1 million (or the remaining amount of the undrawn balance under the IDB Note if such amount were less than $0.1 million). All amounts advanced under the IDB Note were due in full at the earlier of: (i) August 1, 2020, as extended or (ii) on the IDB’s election following the occurrence and continuation of an event of default. The unpaid principal amount of each advance shall bear interest at a rate per annum equal to the rate payable on the Company’s money market account plus a margin of 150 basis points. The interest rate at December 31, 2019 was 2.25%. The IDB Note contains various representations and warranties customary for financings of this type. The obligations of the Company under the IDB Note were collateralized by a security interest in, a general lien upon, and a right of set-off against the Company’s money market account of $15.0 million, which was recorded as restricted cash in the Company's Consolidated Balance Sheets, pursuant to the Assignment and Pledge of Money Market Account, dated as of February 13, 2014 (the “Pledge Agreement”). Pursuant to the Pledge Agreement, the Bank may, after the occurrence and continuation of an event of default under the IDB Note, recover from the money market account all amounts outstanding under the IDB Note. The Pledge Agreement contained various representations, warranties, and covenants customary for pledge agreements of this type. The Company could default on the IDB Note if, among other things, it failed to pay outstanding principal or interest when due. Following the occurrence of an event of default under the IDB Note, the Bank may: (i) declare the entire outstanding principal balance of the IDB Note, together with all accrued interest and other sums due under the IDB Note, to be immediately due and payable; (ii) exercise its right of setoff against any money, funds, credits or other property of any nature in possession of, under control or custody of, or on deposit with IDB; (iii) terminate the commitments of IDB; and (iv) liquidate the money market account to reduce the Company’s obligations to IDB. On September 18, 2017, the maturity on the IDB Note was extended to August 1, 2020. In January 2020, the maturity on the IDB Note was extended to August 1, 2021. The Company applied the 10% cash flow test pursuant to ASC 470 to calculate the difference between the present value of the amended IDB Note’s cash flows and the present value of the original remaining cash flow and concluded that the results didn't exceed the 10% factor, the debt modification is not considered substantially different and therefore did not apply extinguishment accounting, rather it accounted for the modification on a prospective basis pursuant to ASC 470. The Company only paid interest on the IDB Note through maturity. During August 2020, the Company repaid the IDB Note utilizing the cash collateral securing the IDB Note, which was classified as restricted cash on the Company’s Consolidated Balance Sheet. At December 31, 2020 and 2019, the Company had approximately nil and $14.9 million, respectively, outstanding under its promissory note with IDB. 2019 Notes (formerly the Opus Credit Facility) On September 14, 2016, Fortress entered into a Credit Facility Agreement (the “Opus Credit Facility”) with Opus Point Healthcare Innovations Fund, LP (“OPHIF”). Since Fortress’s Chairman, President and Chief Executive Officer (Lindsay A. Rosenwald) and Fortress’s Executive Vice President, Strategic Development (Michael S. Weiss), are Co-Portfolio Managers and Partners of Opus Point Partners Management, LLC (“Opus”), an affiliate of OPHIF, all of the disinterested directors of Fortress’s board of directors approved the terms of the Credit Facility Agreement and accompanying Pledge and Security Agreement and forms of Note and Warrant (collectively, the “Financing Documents”). Pursuant to the Opus Credit Facility, Fortress was eligible to borrow up to a maximum aggregate amount of $25.0 million from OPHIF and any other lender that joins the Credit Facility Agreement from time to time (OPHIF and each subsequent lender, a “Lender”) under one or more convertible secured promissory notes (each a “Note”) from September 14, 2016 until September 1, 2017 (the “Commitment Period”). All amounts borrowed under the Credit Facility Agreement were required to be paid in full by September 14, 2018 (the “Maturity Date”), however Fortress had the right to prepay the Notes at any time without penalty. Pursuant to the Opus Credit Facility and form of Note, each Note will bear interest at 12% per annum and interest will be paid quarterly in arrears commencing on December 1, 2016 and on the first business day of each September, December, March and June thereafter until the Maturity Date. Upon the occurrence and continuance of an event of default (as specified in Credit Facility Agreement and form of Note), each Note will bear interest at 14% and be payable on demand. The Lenders may elect to convert the principal and interest of the Notes at any time into shares of Fortress’s common stock (“Common Stock”) at a conversion price of $10.00 per share. All Notes are secured by shares of capital stock currently held by Fortress in certain Fortress Companies as set forth in the Pledge and Security Agreement entered into between Fortress, its wholly owned subsidiary, FBIO Acquisition, Inc., and OPHIF (as collateral agent on behalf of all the Lenders) on September 14, 2016 (the “Pledge and Security Agreement”). Fortress may terminate the Opus Credit Facility upon notice to the Lenders and payment of all outstanding obligations under the Credit Facility Agreement. Notwithstanding any early termination of the Credit Facility Agreement, within 15 days after termination of the Commitment Period, Fortress will issue each Lender warrants (each a “Warrant”) pursuant to the terms of the Credit Facility Agreement and form of Warrant to purchase their pro rata share of (a) 1,500,000 shares of Common Stock; and (b) that number of shares of Common Stock equal to the product of (i) 1,000,000, times (ii) the principal amount of all Notes divided by 25,000,000. The Warrants will have a five-year term and will be exercisable at a price of $3.00 per share. On March 12, 2018, the Company and OPHIF amended and restated the Opus Credit Facility (the “A&R Opus Credit Facility”). The A&R Opus Credit Facility extended the maturity date of the notes issued under the Opus Credit Facility from September 14, 2018 by one year to September 14, 2019. In September 2019 the A&R Opus Credit Facility was amended to extend the maturity of the notes under the Opus Credit Facility from September 14, 2019 to September 14, 2021. The A&R Opus Credit Facility also permits the Company to make portions of interest and principal repayments in the form of shares of the Company’s common stock and/or in common stock of the Company’s publicly traded subsidiaries, subject to certain conditions. Fortress retains the ability to prepay the Notes at any time without penalty. The notes payable under the A&R Opus Credit Facility continue to bear interest at 12% per annum. The A&R Opus Credit Facility was accounted for as a debt modification for the year ended December 31, 2018. On July 18, 2019, Fortress issued 396,825 common shares of Fortress at $1.26 per share to Dr. Rosenwald. The shares were issued as a prepayment by Fortress of $500,000 of debt owed to Dr. Rosenwald that was held in the name of OPHIF. The prepayment was made in the form of Fortress common stock, measured at the closing price on July 18, 2019, under that certain A&R Opus Credit Facility. Effective December 31, 2019, OPHIF dissolved and distributed it assets among its limited partners. Following the distribution, the $9.0 million facility comprised of separate notes (collectively, the “2019 Notes”) held by DAK Capital Inc. ($3.8 million); Fortress’ Chairman, President and Chief Executive Officer Lindsay A. Rosenwald, M.D. ($0.3 million); Fortress's Executive Vice President, Strategic Development Michael S. Weiss ($2.0 million); and various entities and individuals affiliated with Dr. Rosenwald and Mr. Weiss ($2.9 million). The terms of the 2019 Notes did not change in connection with such reallocations. In August, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $9.0 million balance previously outstanding under the 2019 Notes. As of December 31, 2020 and 2019, nil and $9.0 million, respectively, was outstanding under the 2019 Notes. IDB Letters of Credit The Company has several letters of credit (“LOC”) with IDB securing rent deposits for lease facilities totaling approximately $1.6 million. The LOC’s are secured by cash, which is included in restricted cash on the Company’s Consolidated Balance Sheet 2017 Subordinated Note Financing On March 31, 2017, the Company entered into Note Purchase Agreements (the “Purchase Agreements”) with NAM Biotech Fund II, LLC I (“NAM Biotech Fund”) and NAM Special Situations Fund I QP, LLC (“NAM Special Situations Fund”), both of which are accredited investors, and sold subordinated promissory notes (the “Notes”) of the Company (the “2017 Subordinated Note Financing”) in the aggregate principal amount of $3.25 million. The Notes bear interest at the rate of 8% per annum; additionally, the Notes accrue paid-in-kind interest at the rate of 7% per annum, which will be paid quarterly in shares of the Company’s common stock and/or shares of common stock of one of the Company’s subsidiaries that are publicly traded, in accordance with the terms of the Notes. Each Note is due on the third anniversary of its issuance, provided that the Company may extend the maturity date for two one-year periods in its sole discretion. The 2017 Subordinated Note Financing is for a maximum of $40.0 million (which the Company may, in its sole discretion, increase to $50.0 million). National Securities Corporation (“NSC”), a subsidiary of National and a related party, (see Note 17), pursuant to a Placement Agency Agreement entered into between the Company, NAM Biotech Fund and NSC (the “NAM Placement Agency Agreement”) and a Placement Agency Agreement entered into between the Company, NAM Special Situations Fund and NSC (together with the NAM Placement Agency Agreement, the “Placement Agency Agreements”) acts as placement agent in the 2017 Subordinated Note Financing. Pursuant to the terms of the Placement Agency Agreements, NSC receives (in addition to reimbursement of certain expenses) an aggregate cash fee equal to 10% of the aggregate sales price of the Notes sold in the 2017 Subordinated Note Financing to NAM Biotech Fund and NAM Special Situations Fund. The Placement Agent also receives warrants equal to 10% of the aggregate principal amount of the Notes sold in the 2017 Subordinated Note Financing divided by the closing share price of the Company’s common stock on the date of closing (the “Placement Agent Warrants”). The Placement Agent Warrants are exercisable immediately at such closing share price for a period of five years. The Placement Agent will have a right of first offer for a period of 12 months for any proposed issuance of the Company’s capital stock in a private financing, subject to certain exceptions, and will also have the right to participate as an investor in subsequent financings. On March 31, 2017, the Company held its first closing of the 2017 Subordinated Note Financing and received gross proceeds of $3.2 million. NSC received a cash fee of approximately $0.3 million and warrant to purchase 87,946 shares of the Company’s common stock at an exercise price of per share $3.70. On May 1, 2017, the Company held a second closing of the 2017 Subordinated Note Financing and received gross proceeds of $8.6 million, before expenses. NSC received a placement agent fee of approximately $0.9 million in the second closing and warrants to purchase 234,438 shares of the Company’s common stock at an exercise price of $3.65 per share. On May 31, 2017, the Company held a third closing of the 2017 Subordinated Note Financing and received gross proceeds of $5.3 million, before expenses. NSC received a placement agent fee of approximately $0.5 million in the third closing and warrants to purchase 147,806 shares of the Company’s common stock at an exercise price of $3.61 per share. On June 30, 2017, the Company held a fourth closing of the 2017 Subordinated Note Financing and received gross proceeds of $1.8 million, before expenses. NSC received a placement agent fee of approximately $0.2 million in the fourth closing and warrants to purchase 38,315 shares of the Company’s common stock at an exercise price of $4.75 per share. On August 31, 2017, the Company held a fifth closing of the 2017 Subordinated Note Financing and received gross proceeds of $3.0 million, before expenses. NSC received a placement agent fee of approximately $0.3 million in the fifth closing and warrants to purchase 63,526 shares of the Company’s common stock at an exercise price of $4.75 per share. On September 30, 2017, the Company held a sixth closing of the 2017 Subordinated Note Financing and received gross proceeds of $6.4 million, before expenses. NSC received a placement agent fee of approximately $0.6 million in the sixth closing and warrants to purchase 144,149 shares of the Company’s common stock at an exercise price of $4.42 per share. In August, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $28.4 million balance previously outstanding under the 2017 Subordinated Note Financing. As of December 31, 2020 and 2019, nil and $28.4 million, respectively, was outstanding under the 2017 Subordinated Note Financing. 2018 Venture Notes During the year ended December 31, 2018, the Company closed a private placement of promissory notes for an aggregate of $21.7 million (the “2018 Venture Notes”) through NSC. The Company intends to use the proceeds from the 2018 Venture Notes to acquire and license medical technologies and products through existing or recently formed Company subsidiaries. The Company may also use the proceeds to finance its subsidiaries. The notes mature 36 months from issuance, provided that during the first 24 months the Company may extend the maturity date by six months. No principal amount will be due for the first 24 months (or the first 30 months if the maturity date is extended). Thereafter, the note will be repaid at the rate of 1/12 of the principal amount per month for a period of 12 months. Interest on the note is 8% payable quarterly during the first 24 months (or the first 30 months if the note is extended) and monthly during the last 12 months. NSC acted as the sole placement agent for the 2018 Venture Notes. The Company paid NSC a fee of $1.7 million during the three months ended March 31, 2018 in connection with its placement of the 2018 Venture Notes. The 2018 Venture Notes allows the Company to transfer a portion of the proceeds from the 2018 Venture Notes to a Fortress subsidiary upon the completion by such subsidiary of an initial public offering in which it raises sufficient equity capital so that it has cash equal to five times the amount of the portion of the proceeds of the 2018 Venture Notes so transferred (the “SubCo Funding Threshold”). Through December 31, 2019, the Company had transferred $3.8 million to Aevitas, $1.6 million to Tamid, $2.2 Million to Cyprium and $2.0 million to Cellvation. Notwithstanding such transfers, the Company continued to hold such debt balances as liabilities on its own balance sheet on a consolidated basis, until such time as the SubCo Funding Threshold is met with respect to a particular subsidiary. In connection with this transfer NSC received warrants to purchase each such subsidiary’s stock equal to 25% of that subsidiary’s proceeds of the 2018 Venture Notes divided by the lowest price at which the subsidiary sells its equity in its first third party equity financing. The warrants issued have a term of 10 years and an exercise price equal to the par value of the Fortress subsidiary’s common stock. As of December 31, 2019, the warrants were contingently issuable as neither an initial public offering nor a third-party financing had occurred at any such subsidiary. In August, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $21.7 million balance previously outstanding under the 2018 Venture Notes. As of December 31, 2020 and 2019, nil and $21.7 million, respectively, was outstanding under the 2018 Venture Notes. Mustang Horizon Notes On March 29, 2019 (the "Closing Date"), Mustang entered into a $20.0 million Loan Agreement with Horizon Technology Finance Corporation ("Horizon"), herein referred to as the "Mustang Horizon Notes". In accordance with the Loan Agreement, $15.0 million of the $20.0 million loan was funded on the Closing Date, with the remaining $5.0 million fundable upon Mustang achieving certain predetermined milestones. Each advance under the Mustang Horizon Notes will mature 42 months from the first day of the month following the funding of the advance. The first three advances will mature on October 1, 2022 (the "Loan Maturity Date"). Each advance accrues interest at a per annum rate of interest equal to 9.00% plus the amount by which the one-month LIBOR Rate, as reported in the Wall Street Journal, exceeds 2.50%. The Loan Agreement provides for interest-only payments commencing May 1, 2019, through and including October 1, 2020. The interest-only period may be extended to April 1, 2021, if the Company satisfies the Interest Only Extension Milestone (as defined in the Loan Agreement). Thereafter, commencing May 1, 2021, amortization payments will be payable monthly in eighteen installments of principal and interest. At its option, upon ten business days' prior written notice to Horizon, the Company may prepay all or any portion greater than or equal to $500,000 of each of the outstanding advances by paying the entire principal balance (or portion thereof) and all accrued and unpaid interest, subject to a prepayment charge of 4.0% of the then outstanding principal balance of each advance if such advance is prepaid on or before the Loan Amortization Date (as defined in the Loan Agreement), 3% if such advance is prepaid after the Loan Amortization Date applicable to such Loan, but on or prior to twelve months following the Loan Amortization Date, and 2% thereafter. In addition, a final payment equal to $250,000 for each advance (i.e., $750,000 in aggregate with respect to the initial $15.0 million) is due on the maturity date or other date of payment in full. Amounts outstanding during an event of default shall be payable on demand and shall accrue interest at an additional rate of 5.0% per annum of the past due amount outstanding. Each advance of the loan is secured by a lien on substantially all of the assets of Mustang, other than Intellectual Property and Excluded Collateral (in each case as defined in the Loan Agreement), and contains customary covenants and representations, including a liquidity covenant, financial reporting covenant and limitations on dividends, indebtedness, collateral, investments, distributions, transfers, mergers or acquisitions, taxes, corporate changes, deposit accounts, and subsidiaries. The events of default under the Loan Agreement include, among other things, without limitation, and subject to customary grace periods, (1) Mustang's failure to make any payments of principal or interest under the Loan Agreement, promissory notes or other loan documents, (2) the Mustang's breach or default in the performance of any covenant under the Loan Agreement, (3) the occurrence of a material adverse change, (4) Mustang making a false or misleading representation or warranty in any material respect, (5) the Mustang's insolvency or bankruptcy, (6) certain attachments or judgments on the Mustang's assets, (7) the occurrence of any material default under certain agreements or obligations of Mustang involving indebtedness in excess of $250,000, or (8) failing to maintain certain minimum monthly cash balances which range from approximately $8 to $13 million over the term of the loan ($13.0 million as of December 31, 2019). If an event of default occurs, Horizon is entitled to take enforcement action, including acceleration of amounts due under the Loan Agreement. The Loan Agreement also contains warrant coverage of 5% of the total amount funded. Four warrants (the "Warrants") were issued by Mustang to Horizon to purchase a combined 288,184 shares of Mustang's common stock with an exercise price of $3.47 and a fair value of $0.9 million. The Warrants are exercisable for ten years from the date of issuance. Horizon may exercise the Warrant either by (a) cash or check or (b) through a net issuance conversion. The shares of the Company's common stock will, upon request by Horizon, be registered and freely tradable following a period of six months after issuance. Mustang paid Horizon an initial commitment fee of $0.2 million and reimbursed Horizon for $30,000 of legal fees in connection with the Loan Agreement. Mustang incurred approximately $1.2 million of legal and other direct costs in connection with the Loan Agreement. All fees, warrants and costs paid to Horizon and all direct costs incurred by Mustang are recognized as a debt discount to the funded loans and are amortized to interest expense using the effective interest method over the term of the Loan Agreement. On September 30, 2020, Mustang repaid the amount outstanding under the Horizon Notes in full, which was comprised of $15.0 million face value of the outstanding notes, $0.1 million in accrued and unpaid interest, a $0.8 million final payment fee and prepayment penalties of $0.6 million. Interest Expense The following table shows the details of interest expense for all debt arrangements during the periods presented. Interest expense includes contractual interest and amortization of the debt discount and amortization of fees represents fees associated with loan transaction costs, amortized over the life of the loan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 ​ 2019 ($ in thousands) Interest Fees Total Interest Fees Total IDB Note ​ $ 246 ​ $ — ​ $ 246 ​ $ 356 ​ $ - ​ $ 356 2017 Subordinated Note Financing 1 ​ 2,870 ​ 1,890 ​ 4,760 ​ 4,220 ​ 1,381 ​ 5,601 2019 Notes ​ 710 ​ — ​ 710 ​ 1,113 ​ ​ 336 ​ 1,449 2018 Venture Notes 1 ​ 1,253 ​ 1,000 ​ 2,253 ​ 1,737 ​ 639 ​ 2,376 LOC Fees ​ 34 ​ — ​ 34 ​ 60 ​ — ​ 60 Mustang Horizon Notes 1,3 ​ 1,585 ​ 2,321 ​ 3,906 ​ 1,042 ​ 710 ​ 1,752 Oaktree Note 1 ​ ​ 2,311 ​ ​ 411 ​ ​ 2,722 ​ ​ — ​ ​ — ​ ​ — Note Payable 2 ​ ​ 697 ​ ​ — ​ ​ 697 ​ ​ — ​ ​ 255 ​ ​ 255 Other ​ (2) ​ — ​ (2) ​ — ​ ​ — ​ ​ — Total Interest Expense and Financing Fee ​ $ 9,704 ​ $ 5,622 ​ $ 15,326 ​ $ 8,528 ​ $ 3,321 ​ $ 11,849 ​ Note 1:For the year ended December 31, 2020, includes $1.2 million expense of unamortized debt discount fees for the 2017 Subordinated Note Financing, $0.3 million for the 2018 Venture Notes and $1.8 million for the Mustang Horizon Notes. Note 2: Imputed interest expense related to Ximino purchase (see Note 9). Note 3: Includes $0.6 million of prepayment penalties included in interest expense for the Mustang Horizon Notes.

Accrued Liabilities and other L

Accrued Liabilities and other Long-Term Liabilities	12 Months Ended
	Dec. 31, 2020
Accrued Liabilities and other Long-Term Liabilities
Accrued Liabilities and other Long-Term Liabilities	11. Accrued Liabilities and other Long-Term Liabilities Accrued expenses and other long-term liabilities consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ($ in thousands) 2020 2019 Accrued expenses: ​ ​ Professional fees ​ $ 1,236 ​ $ 1,153 Salaries, bonus and related benefits ​ 6,701 ​ 6,683 Research and development ​ 5,007 ​ 4,215 Research and development - manufacturing ​ 518 ​ 1,017 Research and development - license maintenance fees ​ 461 ​ 361 Research and development - milestones ​ 600 ​ — Accrued royalties payable ​ 2,682 ​ 2,320 Accrued coupon funding expense ​ 10,869 ​ 8,391 Other ​ 1,188 ​ 1,259 Total accrued expenses ​ $ 29,262 ​ $ 25,399 ​ ​ ​ ​ ​ ​ ​ Other long-term liabilities: ​ ​ Deferred rent and long-term lease abandonment charge 1 ​ $ 1,949 ​ $ 2,136 Partner company note payable, long-term ​ ​ ​ ​ ​ ​ Ximino agreement 2 ​ ​ 3,622 ​ ​ 4,990 Isotretinoin agreement 3 ​ ​ 2,792 ​ ​ — Anti-itch product agreement 4 ​ ​ 945 ​ ​ — Total other long-term liabilities and partner company note payable, long-term ​ $ 9,308 ​ $ 7,126 ​ Note 1: Balance consists of deferred charges related to build-out of the New York facility Note 2: As of December 31, 2019, Journey recorded a note payable, net of an imputed interest discount of $2.3 million, of $4.7 million in connection with its acquisition of Ximino, see Note 9. The imputed interest discount was calculating utilizing an 11.96% effective interest rate based upon a non-investment grade “CCC” rate over a five-year period. Amortization of interest discount was $0.6 million and $0.3 million for the years ended December 31, 2020 and 2019, respectively. At December 31, 2020, $2.0 million was classified as Partner company note payable, short-term on the Company’s Consolidated Balance Sheet. Note 3: As of December 31, 2020, Journey recorded a note payable, net of an imputed interest discount of $0.3 million, of $3.7 million in connection with its acquisition of the Isotretinoin agreement, see Note 9. The imputed interest discount was calculated utilizing a 4.00% effective rate, which represents the market rate for an asset-backed three year loan, secured by receivables. Amortization of interest discount was $0.1 million for the year ended December 31, 2020. At December 31, 2020, $0.5 million of note payable was classified as Partner company note payable, short-term on the Company’s Consolidated Balance Sheet. Note 4: As of December 31, 2020, Journey recorded a note payable, net of an imputed interest discount of $0.1 million, of $3.7 million in connection with its acquisition of an anti-itch product, see Note 9. The imputed interest discount was calculated utilizing a 4.25% effective rate, which represents the market rate for an asset-backed three year loan, secured by receivables. Amortization of interest discount was negligible for the year ended December 31, 2020. As of December 31, 2020, $2.8 million of note payable was classified as Partner company note payable, short-term on the Company’s Consolidated Balance Sheet. ​

Non-Controlling Interests

Non-Controlling Interests	12 Months Ended
	Dec. 31, 2020
Non-Controlling Interests
Non-Controlling Interests	12. Non-Controlling Interests Non-controlling interests in consolidated entities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ ​ ​ As of December 31, 2020 ​ December 31, 2020 ​ As of December 31, 2020 ​ ​ ​ ​ ​ ​ ​ Net loss attributable to ​ Non-controlling interests ​ Non-controlling ($ in thousands) NCI equity share ​ non-controlling interests ​ in consolidated entities ​ ownership Acquisition Corp VIII ​ $ (7) ​ $ (27) ​ $ (34) 10.0 % Aevitas ​ ​ (2,370) ​ (823) ​ (3,193) 39.0 % Avenue 2 ​ 5,800 ​ (3,974) ​ 1,826 77.4 % Baergic ​ (1,662) ​ (97) ​ (1,759) 39.5 % Cellvation ​ (1,089) ​ (182) ​ (1,271) 22.1 % Checkpoint 1 ​ 41,704 ​ (13,265) ​ 28,439 80.4 % Coronado SO ​ (290) ​ — ​ (290) 13.0 % Cyprium ​ 567 ​ (1,478) ​ (911) 30.5 % Helocyte ​ (4,986) ​ (259) ​ (5,245) 18.8 % JMC ​ 138 ​ 491 ​ 629 7.1 % Mustang 2 ​ 116,060 ​ (36,429) ​ 79,631 80.9 % Oncogenuity ​ ​ (82) ​ (376) ​ (458) 25.3 % Tamid ​ (663) ​ (40) ​ (703) 22.8 % Total ​ $ 153,120 ​ $ (56,459) ​ $ 96,661 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ ​ ​ ​ ​ As of December 31, 2019 ​ December 31, 2019 ​ As of December 31, 2019 ​ ​ ​ ​ ​ ​ ​ Net loss attributable to ​ Non-controlling interests ​ Non-controlling ($ in thousands) NCI equity share non-controlling interests in consolidated entities ownership Aevitas ​ $ (1,249) ​ $ (694) ​ $ (1,943) 35.8 % Avenue 2 ​ 24,269 ​ (19,011) ​ 5,258 77.3 % Baergic ​ 23 ​ (1,162) ​ (1,139) 33.0 % Cellvation ​ (732) ​ (158) ​ (890) 20.6 % Checkpoint 1 ​ 29,389 ​ (14,687) ​ 14,702 78.0 % Coronado SO ​ (290) ​ — ​ (290) 13.0 % Cyprium ​ (320) ​ (99) ​ (419) 10.6 % Helocyte ​ (4,322) ​ (402) ​ (4,724) 19.3 % JMC ​ (211) ​ 325 ​ 114 6.9 % Mustang 2 ​ 62,025 ​ (25,727) ​ 36,298 70.3 % Tamid ​ (565) ​ (85) ​ (650) 22.8 % Total ​ $ 108,017 ​ $ (61,700) ​ $ 46,317 ​ ​ ​ Note 1: Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights. Note 2: Avenue and Mustang are consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Preferred Class A Shares which provide super-majority voting rights.

Net Loss per Common Share

Net Loss per Common Share	12 Months Ended
	Dec. 31, 2020
Net Loss per Common Share
Net Loss per Common Share	13. Net Loss per Common Share Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of Common Stock outstanding during the period, without consideration for Common Stock equivalents. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of Common Stock and Common Stock equivalents outstanding for the period. The following shares of potentially dilutive securities, weighted during the years ended December 31, 2020 and 2019 have been excluded from the computations of diluted weighted average shares outstanding as the effect of including such securities would be antidilutive: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Warrants to purchase Common Stock 3,419,812 2,729,186 Options to purchase Common Stock 1,103,643 1,179,680 Convertible preferred stock — 1,038,251 Unvested Restricted Stock 14,302,004 12,625,144 Unvested Restricted Stock Units 391,336 721,478 Total 19,216,795 18,293,739 ​

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity
Stockholders' Equity	14. Stockholders’ Equity Common Stock At the Company’s 2020 Annual Meeting of Stockholders held on June 17, 2020, its stockholders approved an amendment to its certificate of incorporation to increase the number of authorized shares of common stock available to issue by 50,000,000 to 150,000,000 with a par value of $0.001 per share. The amendment was filed with the Secretary of State of the State of Delaware on June 18, 2020. The terms, rights, preference and privileges of the Common Stock are as follows: Voting Rights Each holder of Common Stock is entitled to one vote per share of Common Stock held on all matters submitted to a vote of the stockholders,f including the election of directors. The Company’s certificate of incorporation and bylaws do not provide for cumulative voting rights. Dividends Subject to preferences that may be applicable to any then outstanding preferred stock, the holders of the Company’s outstanding shares of Common Stock are entitled to receive dividends, if any, as may be declared from time to time by the Company’s Board of Directors out of legally available funds. Liquidation In the event of the Company’s liquidation, dissolution or winding up, holders of Common Stock will be entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of the Company’s debts and other liabilities, subject to the satisfaction of any liquidation preference granted to the holders of any outstanding shares of Preferred Stock. Rights and Preference Holders of the Company’s Common Stock have no preemptive, conversion or subscription rights, and there is no redemption or sinking fund provisions applicable to the Common Stock. The rights, preferences and privileges of the holders of Common Stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of the Company’s preferred stock that are or may be issued. Fully Paid and Nonassessable All of the Company’s outstanding shares of Common Stock are fully paid and nonassessable. Series A Preferred Stock On October 26, 2017, the Company designated 5,000,000 shares of $0.001 par value preferred stock as Series A Preferred Stock. As of December 31, 2020, and 2019, 3,427,138 and 1,341,167 shares, respectively, of Series A Preferred Stock were issued and outstanding. The terms, rights, preference and privileges of the Series A Preferred Stock are as follows: Voting Rights Except as may be otherwise required by law, the voting rights of the holders of the Series A Preferred Stock are limited to the affirmative vote or consent of the holders of at least two-thirds of the votes entitled to be cast by the holders of the Series A Preferred Stock outstanding at the time in connection with the: (1) authorization or creation, or increase in the authorized or issued amount of, any class or series of capital stock ranking senior to the Series A Preferred Stock with respect to payment of dividends or the distribution of assets upon liquidation, dissolution or winding up or reclassification of any of the Company’s authorized capital stock into such shares, or creation, authorization or issuance of any obligation or security convertible into or evidencing the right to purchase any such shares; or (2) amendment, alteration, repeal or replacement of the Company’s certificate of incorporation, including by way of a merger, consolidation or otherwise in which the Company may or may not be the surviving entity, so as to materially and adversely affect and deprive holders of Series A Preferred Stock of any right, preference, privilege or voting power of the Series A Preferred Stock. Dividends Dividends on Series A Preferred Stock accrue daily and will be cumulative from, and including, the date of original issue and shall be payable monthly at the rate of 9.375% per annum of its liquidation preference, which is equivalent to $2.34375 per annum per share. The first dividend on Series A Preferred Stock sold in the offering was payable on December 31, 2017 (in the amount of $0.299479 per share) to the holders of record of the Series A Preferred Stock at the close of business on December 15, 2017 and thereafter for each subsequent quarter in the amount of $0.5839375 per share. The Company recorded approximately $6.5 million and $2.6 million of dividends in Additional Paid in Capital on the Consolidated Balance Sheets as of December 31, 2020 and 2019, respectively. No Maturity Date or Mandatory Redemption The Series A Preferred Stock has no maturity date, and the Company is not required to redeem the Series A Preferred Stock. Accordingly, the Series A Preferred Stock will remain outstanding indefinitely unless the Company decides to redeem it pursuant to its optional redemption right or its special optional redemption right in connection with a Change of Control (as defined below), or under the circumstances set forth below under “Limited Conversion Rights Upon a Change of Control” and elect to convert such Series A Preferred Stock. The Company is not required to set aside funds to redeem the Series A Preferred Stock. Optional Redemption The Series A Preferred Stock may be redeemed in whole or in part (at the Company’s option) any time on or after December 15, 2022, upon not less than 30 days nor more than 60 days’ written notice by mail prior to the date fixed for redemption thereof, for cash at a redemption price equal to $25.00 per share, plus any accumulated and unpaid dividends to, but not including, the redemption date. Special Optional Redemption Upon the occurrence a Change of Control (as defined below), the Company may redeem the shares of Series A Preferred Stock, at its option, in whole or in part, within one hundred twenty (120) days of any such Change of Control, for cash at $25.00 per share, plus accumulated and unpaid dividends (whether or not declared) to, but excluding, the redemption date. If, prior to the Change of Control conversion date, the Company has provided notice of its election to redeem some or all of the shares of Series A Preferred Stock (whether pursuant to the Company’s optional redemption right described above under “Optional Redemption” or this special optional redemption right), the holders of shares of Series A Preferred Stock will not have the Change of Control conversion right with respect to the shares of Series A Preferred Stock called for redemption. If the Company elects to redeem any shares of the Series A Preferred Stock as described in this paragraph, the Company may use any available cash to pay the redemption price. A “Change of Control” is deemed to occur when, after the original issuance of the Series A Preferred Stock, the following have occurred and are continuing: ● the acquisition by any person, including any syndicate or group deemed to be a “person” under Section 13(d)(3) of the Exchange Act of beneficial ownership, directly or indirectly, through a purchase, merger or other acquisition transaction or series of purchases, mergers or other acquisition transactions of the Company’s stock entitling that person to exercise more than 50% of the total voting power of all the Company’s stock entitled to vote generally in the election of the Company’s directors (except that such person will be deemed to have beneficial ownership of all securities that such person has the right to acquire, whether such right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition); and ● following the closing of any transaction referred to in the bullet point above, neither the Company nor the acquiring or surviving entity has a class of common equity securities (or American Depositary Receipts representing such securities) listed on the NYSE, the NYSE American LLC or the Nasdaq Stock Market, or listed or quoted on an exchange or quotation system that is a successor to the NYSE, the NYSE American LLC or the Nasdaq Stock Market. Conversion, Exchange and Preemptive Rights Except as described below under “Limited Conversion Rights upon a Change of Control,” the Series A Preferred Stock is not subject to preemptive rights or convertible into or exchangeable for any other securities or property at the option of the holder. Limited Conversion Rights upon a Change of Control Upon the occurrence of a Change of Control, each holder of shares of Series A Preferred Stock will have the right (unless, prior to the Change of Control Conversion Date, the Company has provided or provides irrevocable notice of its election to redeem the Series A Preferred Stock as described above under “Optional Redemption,” or “Special Optional Redemption”) to convert some or all of the shares of Series A Preferred Stock held by such holder on the Change of Control Conversion Date, into the Common Stock Conversion Consideration, which is equal to the lesser of: ● the quotient obtained by dividing (i) the sum of the $25.00 liquidation preference per share of Series A Preferred Stock plus the amount of any accumulated and unpaid dividends (whether or not declared) to, but not including, the Change of Control Conversion Date (unless the Change of Control Conversion Date is after a record date for a Series A Preferred Stock dividend payment and prior to the corresponding Dividend Payment Date, in which case no additional amount for such accumulated and unpaid dividend will be included in this sum) by (ii) the Common Stock Price (such quotient, the “Conversion Rate”); and ● 13.05483 shares of common stock, subject to certain adjustments. In the case of a Change of Control pursuant to which the Company’s common stock will be converted into cash, securities or other property or assets, a holder of Series A Preferred Stock will receive upon conversion of such Series A Preferred Stock the kind and amount of Alternative Form Consideration which such holder would have owned or been entitled to receive upon the Change of Control had such holder held a number of shares of the Company’s common stock equal to the Common Stock Conversion Consideration immediately prior to the effective time of the Change of Control. Notwithstanding the foregoing, the holders of shares of Series A Preferred Stock will not have the Change of Control Conversion Right if the acquiror has shares listed or quoted on the NYSE, the NYSE American LLC or Nasdaq Stock Market or listed or quoted on an exchange or quotation system that is a successor to the NYSE, the NYSE American LLC or Nasdaq Stock Market, and the Series A Preferred Stock becomes convertible into or exchangeable for such acquiror’s listed shares upon a subsequent Change of Control of the acquiror. Liquidation Preference In the event the Company liquidates, dissolves or is wound up, holders of the Series A Preferred Stock will have the right to receive $25.00 per share, plus any accumulated and unpaid dividends to, but not including, the date of payment, before any payment is made to the holders of the Company’s common stock. Ranking The Series A Preferred Stock will rank, with respect to rights to the payment of dividends and the distribution of assets upon the Company’s liquidation, dissolution or winding up, (1) senior to all classes or series of the Company’s common stock and to all other equity securities issued by the Company other than equity securities referred to in clauses (2) and (3); (2) on a par with all equity securities issued by the Company with terms specifically providing that those equity securities rank on a par with the Series A Preferred Stock with respect to rights to the payment of dividends and the distribution of assets upon the Company’s liquidation, dissolution or winding up; (3) junior to all equity securities issued by the Company with terms specifically providing that those equity securities rank senior to the Series A Preferred Stock with respect to rights to the payment of dividends and the distribution of assets upon the Company liquidation, dissolution or winding up; and (4) junior to all of the Company’s existing and future indebtedness. Stock-Based Compensation As of December 31, 2020, the Company had four equity compensation plans: the Fortress Biotech, Inc. 2007 Stock Incentive Plan (the “2007 Plan”), the Fortress Biotech, Inc. 2013 Stock Incentive Plan, as amended (the “2013 Plan”), the Fortress Biotech, Inc. 2012 Employee Stock Purchase Plan (the “ESPP”) and the Fortress Biotech, Inc. Long Term Incentive Plan (“LTIP”). In 2007, the Company’s Board of Directors adopted and stockholders approved the 2007 Plan authorizing the Company to grant up to 6,000,000 shares of Common Stock to eligible employees, directors, and consultants in the form of restricted stock, stock options and other types of grants. In 2013, the Company’s Board of Directors adopted and stockholders approved the 2013 Plan authorizing the Company to grant up to 2,300,000 shares of Common Stock to eligible employees, directors, and consultants in the form of restricted stock, stock options and other types of grants. In 2015, the Company’s Board of Directors and stockholders approved an increase of 7,700,000 shares for the 2013 Plan and in 2020, the Company’s Board of Directors and stockholders approved an increase of 3,000,000 shares bringing the total number of shares approved under this plan to 13,000,000, with the aggregate total of authorized shares available for grants under the 2007 Plan and the 2013 Plan of up to 19,000,000 shares. An aggregate 14,721,911 shares were granted under both the Company’s 2007 and 2013 plans, net of cancellations, and 4,278,089 shares were available for issuance as of December 31, 2020. Certain partner companies have their own equity compensation plan under which shares are granted to eligible employees, directors and consultants in the form of restricted stock, stock options, and other types of grants of stock of the respective partner company’s common stock. The table below provides a summary of those plans as of December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ Partner ​ ​ ​ Shares ​ Shares available at Company Stock Plan Authorized December 31, 2020 Aevitas ​ Aevitas Therapeutics, Inc. 2018 Long Term Incentive Plan ​ 2,000,000 ​ 1,602,000 Avenue Avenue Therapeutics, Inc. 2015 Stock Plan 2,000,000 229,436 Baergic FBIO Acquisition Corp. III 2017 Incentive Plan 2,000,000 1,150,000 Cellvation Cellvation Inc. 2016 Incentive Plan 2,000,000 300,000 Checkpoint Checkpoint Therapeutics, Inc. Amended and Restated 2015 Stock Plan 9,000,000 4,288,465 Cyprium Cyprium Therapeutics, Inc. 2017 Stock Plan 2,000,000 575,000 Helocyte DiaVax Biosciences, Inc. 2015 Incentive Plan 2,000,000 341,667 Journey Journey Medical Corporation 2015 Stock Plan 3,642,857 34,000 Mustang Mustang Bio, Inc. 2016 Incentive Plan 5,000,000 1,180,085 Oncogenuity, Inc. ​ FBIO Acquisition Corp. VII 2017 Incentive Plan ​ 2,000,000 ​ 1,600,000 Tamid FBIO Acquisition Corp. V 2017 Incentive Plan 2,000,000 1,600,000 ​ The purpose of the Company’s and partner company’s equity compensation plans is to provide for equity awards as part of an overall compensation package of performance-based rewards to attract and retain qualified personnel. Such awards include, without limitation, options, stock appreciation rights, sales or bonuses of restricted stock, restricted stock units or dividend equivalent rights, and an award may consist of one such security or benefit, or two or more of them in any combination or alternative. Vesting of awards may be based upon the passage of time, the occurrence of one or more events, or the satisfaction of performance criteria or other conditions. Incentive and non-statutory stock options are granted pursuant to option agreements adopted by the plan administrator. Options generally have 10-year contractual terms and vest in three equal annual installments commencing on the grant date. The Company estimates the fair value of stock option grants using a Black-Scholes option pricing model. In applying this model, the Company uses the following assumptions: ● Risk-Free Interest Rate : The risk-free interest rate is based on the yields of United States Treasury securities with maturities similar to the expected term of the options for each option group. ● Volatility : The Company utilizes the trading history of its Common Stock to determine the expected stock price volatility for its Common Stock. ● Expected Term : Due to the limited exercise history of the Company’s stock options, the Company determined the expected term based on the Simplified Method under SAB 107 and the expected term for non-employees is the remaining contractual life for both options and warrants. ● Expected Dividend Rate : The Company has not paid and does not anticipate paying any cash dividends in the near future on its common stock. The fair value of each option award was estimated on the grant date using the Black-Scholes option-pricing model and expensed under the straight-line method. The following table summarizes the stock-based compensation expense from stock option, employee stock purchase programs and restricted Common Stock awards and warrants for the years ended December 31, 2020 and 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ($ in thousands) 2020 2019 Employee awards ​ $ 4,991 ​ $ 3,666 Executive awards of Fortress Companies' stock ​ 1,504 ​ 1,428 Non-employee awards ​ 159 ​ 121 Warrants ​ ​ 130 ​ ​ 97 Partner Companies: ​ ​ ​ ​ ​ ​ Avenue ​ 710 ​ 1,839 Checkpoint ​ 2,780 ​ 3,121 Mustang ​ 2,987 ​ 2,664 Other ​ 190 ​ 252 Total stock-based compensation expense ​ $ 13,451 ​ $ 13,188 ​ For the years ended 2020 and 2019, $3.2 million and $2.8 million was included in research and development expenses, and $10.3 million and $10.4 million was included in selling, general and administrative expenses, respectively. Options The following table summarizes Fortress stock option activities excluding activities related to partner companies: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average ​ ​ ​ ​ ​ ​ ​ Total ​ remaining ​ ​ ​ ​ Weighted average ​ weighted average ​ contractual life ​ Shares exercise price intrinsic value (years) Options vested and expected to vest at December 31, 2018 ​ 1,285,501 ​ $ 3.75 ​ $ — ​ 2.93 Granted ​ 125,000 ​ ​ 1.18 ​ ​ 173,750 ​ ​ Options vested and expected to vest at December 31, 2019 1,410,501 ​ $ 4.30 ​ $ 684,752 2.33 Exercised (100,000) ​ ​ 1.18 ​ — — Forfeited ​ (257,011) ​ ​ 2.57 ​ ​ — ​ — Options vested and expected to vest at December 31, 2020 1,053,490 ​ $ 5.02 ​ $ 647,482 2.63 ​ During the years ended December 31, 2020 and 2019, there were no exercises of stock options. As of December 31, 2020, the Company had no unrecognized stock-based compensation expense related to options. Restricted Stock Stock-based compensation expense from restricted stock awards and restricted stock units for the years ended December 31, 2020 and 2019 was $12.5 million and $11.5 million, respectively. During 2020, the Company granted 1.9 million restricted shares of its Common Stock to executives and directors of the Company and 0.6 million restricted stock units to employees and non-employees of the Company. The fair value of the restricted stock awards issued during 2020 of $4.8 million and the fair value of the restricted stock unit awards issued during 2020 of $2.4 million were estimated on the grant date using the Company’s stock price as of the grant date. The 2020 restricted stock awards and restricted stock unit awards vest upon both the passage of time as well as meeting certain performance criteria. Restricted stock awards and restricted stock unit awards are expensed under the straight-line method over the vesting period. Expense for awards with performance-based vesting criteria will be measured and recorded if and when it becomes probable that the milstone will be achieved. ​ During 2019, the Company granted 1.5 million restricted shares of its Common Stock to executives and directors of the Company and 0.3 million restricted stock units to employees and non-employees of the Company. The fair value of the restricted stock awards issued during 2019 of $1.4 million and the fair value of the restricted stock unit awards issued during 2019 of $0.4 million were estimated on the grant date using the Company’s stock price as of the grant date. The 2019 restricted stock awards and restricted stock unit awards vest upon both the passage of time as well as meeting certain performance criteria. Restricted stock awards and restricted stock unit awards are expensed under the straight-line method over the vesting period. Expense for awards with performance-based vesting criteria will be measured and recorded if and when it becomes probable that the milstone will be achieved. The following table summarizes Fortress restricted stock awards and restricted stock units activities, excluding activities related to Fortress subsidiaries: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ average grant ​ ​ Number of shares ​ price Unvested balance at December 31, 2018 12,645,982 ​ $ 2.72 Restricted stock granted 1,546,408 ​ 0.88 Restricted stock vested (220,000) ​ 3.16 Restricted stock units granted ​ 290,000 ​ ​ 1.49 Restricted stock units forfeited (135,416) ​ 3.91 Restricted stock units vested (358,960) ​ 3.61 Unvested balance at December 31, 2019 ​ 13,768,014 ​ $ 2.46 Restricted stock granted ​ 1,873,072 ​ ​ 2.57 Restricted stock vested ​ (230,000) ​ ​ 2.78 Restricted stock units granted ​ 630,126 ​ ​ 3.82 Restricted stock units forfeited ​ (148,750) ​ ​ 3.30 Restricted stock units vested ​ (384,958) ​ ​ 3.49 Unvested balance at December 31, 2020 ​ 15,507,504 ​ $ 2.49 ​ The total fair value of restricted stock units and awards that vested during the years ended December 31, 2020 and 2019 was $2.0 million and $2.0 million, respectively. As of December 31, 2020, the Company had unrecognized stock-based compensation expense related to all unvested restricted stock and restricted stock unit awards of $12.6 million and $3.1 million, respectively, which is expected to be recognized over the remaining weighted-average vesting period of 4.1 years and 2.8 years, respectively. This amount does not include 0.1 million restricted stock units as of December 31, 2020 which are performance-based and vest upon achievement of certain corporate milestones. Stock-based compensation for these awards will be measured and recorded if and when it is probable that the milestone will be achieved. Deferred Compensation Plan On March 12, 2015, the Company’s Compensation Committee approved the Deferred Compensation Plan allowing all non-employee directors the opportunity to defer all or a portion of their fees or compensation, including restricted stock and restricted stock units. During the year ended December 31, 2020 and 2019, certain non-employee directors elected to defer an aggregate of 230,000 and 230,000 restricted stock awards, respectively, under this plan. Employee Stock Purchase Plan Eligible employees can purchase the Company’s Common Stock at the end of a predetermined offering period at 85% of the lower of the fair market value at the beginning or end of the offering period. The ESPP is compensatory and results in stock-based compensation expense. As of December 31, 2020, 577,301 shares have been purchased and 422,699 shares are available for future sale under the Company’s ESPP. The Company recognized share-based compensation expense of $0.1 million and $0.1 million for the years ended December 31, 2020 and 2019, respectively. Warrants The following table summarizes Fortress warrant activities, excluding activities related to partner companies: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total weighted ​ Weighted average ​ ​ ​ ​ ​ ​ ​ average ​ remaining ​ ​ Number of ​ Weighted average ​ intrinsic ​ contractual life ​ shares exercise price value (years) Outstanding as of December 31, 2018 2,754,189 ​ $ 3.28 ​ $ — ​ 3.49 Granted ​ 60,000 ​ ​ 1.92 ​ ​ 39,000 ​ — Forfeited ​ (73,009) ​ 5.65 ​ — ​ — Outstanding as of December 31, 2019 2,741,180 ​ $ 3.19 ​ $ 111,000 2.73 Granted 1,849,450 ​ 3.14 ​ 101,000 — Forfeited (9) ​ 3.00 ​ 2 — Outstanding as of December 31, 2020 4,590,621 ​ $ 3.17 ​ $ 607,848 4.85 Exercisable as of December 31, 2020 4,430,621 ​ $ 3.21 ​ $ 452,848 4.80 ​ During 2020, in connection with the issuance of the Oaktree Note, the Company issued warrants to purchase 1,749,450 shares of common stock; in connection with a consulting agreement the Company issued warrants to purchase 100,000 shares of common stock. The relative fair value of the Oaktree warrants was recorded to debt discount and will be amortized over the term of the Oaktree Note (see Note 10). As of December 31, 2020, the Company had no unrecognized stock-based compensation expense related to warrants. Long-Term Incentive Program (“LTIP”) On July 15, 2015, the stockholders approved the LTIP for the Company’s Chairman, President and Chief Executive Officer, Dr. Rosenwald, and Executive Vice Chairman, Strategic Development, Mr. Weiss. The LTIP consists of a program to grant equity interests in the Company and in the Company’s subsidiaries, and a performance-based bonus program that is designed to result in performance-based compensation that is deductible without limit under Section 162(m) of the Internal Revenue Code of 1986, as amended. On January 1, 2020 and 2019, the Compensation Committee granted 801,536 and 648,204 shares each to Dr. Rosenwald and Mr. Weiss, respectively. These equity grants, made in accordance with the LTIP, represent 1% of total outstanding shares of the Company as of the dates of such grants and were granted in recognition of their performance in 2019 and 2018. The shares are subject to repurchase by the Company until both of the following conditions are met: (i) the Company’s market capitalization increases by a minimum of $100.0 million, and (ii) the employee is either in the service of the Company as an employee or as a Board member (or both) on the tenth anniversary of the LTIP, or the eligible employee has had an involuntary separation from service (as defined in the LTIP). The Company’s repurchase option on such shares will also lapse upon the occurrence of a corporate transaction (as defined in the LTIP) if the eligible employee is in service on the date of the corporate transaction. The fair value of each grant on the grant date was approximately $2.1 million for the 2020 grant and $0.6 million for the 2019 grant. For the year ended December 31, 2020 and 2019, the Company recorded stock compensation expense of approximately $2.5 million and $1.4 million, respectively related to the LTIP grants on the Consolidated Statements of Operations. ​ Capital Raise 2019 Common Stock At the Market Offering On June 28, 2019, the Company entered into an At Market Issuance Sales Agreement (“2019 Common ATM”), with Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., Jones Trading Institutional Services LLC and B. Riley, as selling agents, governing potential sales of the Company’s common stock. For the years ended December 31, 2020 and 2019, the Company issued approximately 17.4 million and 3.8 million shares of common stock, respectively, for gross proceeds of $47.5 million and $5.6 million, respectively, at an average selling price of $2.73 and $1.49, respectively. Under the 2019 Common ATM, the Company pays the agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of common stock, and in connection with these sales, with respect to the years ended December 31, 2020 and 2019, the Company paid aggregate fees of approximately $1.4 million and $0.2 million, respectively. Common Stock At the Market Offering On August 17, 2016, the Company entered into an Amended and Restated At Market Issuance Sales Agreement, or Sales Agreement, with MLV & Co. LLC, or MLV, and FBR Capital Markets & Co., or FBR (“ATM”). On August 18, 2016, the Company filed a Registration Statement on Form S-3, which became effective on December 1, 2016 and permits the Company to issue and sell shares of its common stock having an aggregate offering price of up to $53.0 million from time to time through MLV and FBR, as sales agents under the Sales Agreement. The Sales Agreement terminated on August 17, 2019. Pursuant to the terms of the ATM, for the year ended December 31, 2019, the Company issued approximately 8.0 million shares of common stock, respectively, at an average price of $1.88 per share for gross proceeds of $15.1 million. In connection with these sales, the Company paid aggregate fees of approximately $0.3 million, respectively. 2019 9.375% Series A Cumulative Redeemable Perpetual Preferred Stock Offering In November 2019, the Company completed an underwritten public offering of 262,500 shares of its 9.375% Series A Cumulative Redeemable Perpetual Preferred Stock, (Nasdaq: FBIOP) (the "Preferred Stock"), (plus a 45-day option to purchase up to an additional 39,375 shares, which was exercised in November, 2019) at a price of $20 per share for gross proceeds of approximately $6.0 million, before deducting underwriting discounts and commissions and offering expenses. On February 14, 2020, the Company announced the closing of an underwritten public offering, whereby it sold 625,000 shares of its Preferred Stock, (plus a 45-day option to purchase up to an additional 93,750 shares, which was exercised in February 2020) at a price of $20.00 per share for gross proceeds of approximately $14.4 million, before deducting underwriting discounts and commissions and offering expenses of approximately $1.3 million. On May 29, 2020, the Company closed on an underwritten public offering whereby it sold 555,556 shares of its Preferred Stock, (plus a 45-day option to purchase up to an additional 83,333 shares, which was exercised in May 2020) at a price of $18.00 per share for gross proceeds of approximately $11.5 million, before deducting underwriting discounts and commissions and offering expenses of approximately $1.1 million. On August 26, 2020, the Company closed on an underwritten public offering whereby it sold 666,666 shares of its Preferred Stock, (plus a 45-day option to purchase up to an additional 66,666 shares, which was exercised in August 2020) at a price of $18.00 per share for gross proceeds of approximately $13.2 million, before deducting underwriting discounts and commissions and offering expenses of approximately $1.1 million. ​ 2018 9.375% Series A Cumulative Redeemable Perpetual Preferred Stock At the Market Offering On April 5, 2018, the Company entered into an At Market Sales Agreement (the “2018 Preferred ATM”), with B. Riley, National Securities Corporation, LifeSci Capital LLC, Maxim Group LLC and Noble Capital Markets, Inc. as selling agents, governing the issuance of the Company’s 9.375% Series A Cumulative Redeemable Perpetual Preferred Stock (“Perpetual Preferred Stock”). For the year ended December 31, 2019, the Company issued 39,292 shares of Perpetual Preferred Stock for gross proceeds $0.8 million at an average selling price of $20.67. No shares of Perpetual Preferred Stock were issued in 2018. Under the 2018 Preferred ATM, the Company pays the agents a commission rate of up to 7.0% of the gross proceeds from the sale of any shares of Perpetual Preferred Stock, and in connection with these sales, with respect to the year ended December 31, 2019, the Company paid aggregate fees of approximately $24,000. The above-mentioned shares of Perpetual Preferred Stock were sold under the 2016 Shelf. The 2016 Shelf expired on December 1, 2019. 2019 Shelf The 2019 offerings of both common stock and preferred stock were sold under the Company’s shelf registration statement on Form S-3 originally filed on July 6, 2018 and declared effective July 23, 2019 (the “2019 Shelf”). The shares of common stock were sold under the Company’s shelf registration statement on Form S-3 originally filed on July 6, 2018 and declared effective July 23, 2019 (the “2019 Shelf”) through May 27, 2020. 2020 Shelf On May 18, 2020, the Company filed a new shelf registration statement on Form S-3, which was declared effective on May 26, 2020 (the "2020 Shelf"). In connection with the 2020 Shelf, the Company entered into an At Market Issuance Sales Agreement ("2020 Common ATM"), with Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., B. Riley and Dawson James Securities, Inc., as selling agents, governing potential sales of the Company's common stock. ATM sales commencing on June 1, 2020 were made under the 2020 Shelf as were Perpetual Preferred Offerings. Approximately $26.7 million of securities remain available for sale under the 2020 Shelf at Decembe

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies
Commitments and Contingencies	15. Commitments and Contingencies Leases On October 3, 2014, the Company entered into a 15-year lease for office space at 2 Gansevoort Street, New York, NY 10014, at an average annual rent of $2.5 million. The Company took possession of this space, which serves as its principal executive offices, in December 2015, and took occupancy in April 2016. Total rent expense, over the full term of the lease for this space will approximate $40.7 million. In conjunction with the lease, the Company entered into Desk Space Agreements with two related parties: OPPM and TGTX, to occupy 10% and 45%, respectively, of the office space that requires them to pay their share of the average annual rent of $0.3 million and $1.1 million, respectively. The total net rent expense will approximate $16.0 million over the lease term. These initial rent allocations will be adjusted periodically for each party based upon actual percentage of the office space occupied. Additionally, the Company has reserved the right to execute desk space agreements with other third parties and those arrangements will also affect the cost of the lease actually borne by us. In October 2015, the Company entered into a 5-year lease for approximately 6,100 square feet of office space in Waltham, MA at an average annual rent of approximately $0.2 million. The Company took occupancy of this space in January 2016. In December 2020, we amended our lease and entered into a new two-year extension of the same office space in Waltham, MA at an average annual rent of $0.2 million. The term of this amended lease commences on April 1, 2021 and will expire on March 31, 2023. Journey In June 2017, Journey extended its lease for 2,295 square feet of office space in Scottsdale, AZ by one year, at an average annual rent of approximately $55,000. Journey originally took occupancy of this space in November 2014. In August 2018, Journey amended their lease and entered into a new two-year extension for 3,681 square feet of office space in the same location in Scottsdale, AZ at an annual rate of approximately $94,000. The term of this amended lease commenced on December 1, 2018 and will expire on November 30, 2020. In August 2020, Journey amended their lease and entered into a new 25-month extension of the same office space in Scottsdale, AZ at an average annual rent of $0.1 million. The term of this amended lease commenced on December 1, 2020 and will expire on December 31, 2022. Mustang On October 27, 2017, Mustang entered into a lease agreement with WCS - 377 Plantation Street, Inc., a Massachusetts nonprofit corporation (“Landlord”). Pursuant to the terms of the lease agreement, Mustang agreed to lease 27,043 square feet from the Landlord, located at 377 Plantation Street in Worcester, MA (the “Facility”), through November 2026, subject to additional extensions at Mustang’s option. Base rent, net of abatements of $0.6 million over the lease term, totals approximately $3.6 million, on a triple-net basis. The terms of the lease also require that Mustang post an initial security deposit of $0.8 million, in the form of $0.5 million letter of credit and $0.3 million in cash, which increased to $1.3 million ($1.0 million letter of credit, $0.3 million in cash) on November 1, 2019. After the fifth lease year, the letter of credit obligation is subject to reduction. The Facility began operations for the production of personalized CAR T and gene therapies in 2018. The Company leases copiers under agreements classified as operating leases that expire on various dates through 2024. Most of the Company’s lease liabilities result from the lease of its New York City, NY office, which expires in 2031 2026 During the years ended December 31, 2020 and 2019, the Company recorded $3.2 million and $3.2 million, respectively, as lease expense to current period operations. ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ($ in thousands) ​ 2020 ​ 2019 Lease Cost ​ ​ ​ ​ ​ Operating lease cost ​ $ 3,246 ​ $ 3,199 Shared lease costs ​ (1,873) ​ ​ (1,876) Variable lease cost ​ 593 ​ ​ 801 Total lease expense ​ $ 1,966 ​ $ 2,124 ​ The following tables summarize quantitative information about the Company’s operating leases, under the adoption of ASC Topic 842 , Leases ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ($ in thousands) ​ 2020 ​ 2019 Operating cash flows from operating leases ​ $ (2,958) ​ $ (3,001) ​ Right-of-use assets exchanged for new operating lease liabilities ​ ​ 634 ​ ​ — ​ Weighted-average remaining lease term – operating leases (years) ​ 5.7 ​ 6.3 ​ Weighted-average discount rate – operating leases ​ 6.3 % 6.2 % ​ ​ ​ ​ ​ ​ Future Lease ($ in thousands) ​ Liability Year Ended December 31, 2021 ​ $ 3,353 Year Ended December 31, 2022 ​ 3,461 Year Ended December 31, 2023 ​ 3,233 Year Ended December 31, 2024 ​ 3,193 Year Ended December 31, 2025 ​ 3,244 Other ​ 17,028 Total operating lease liabilities ​ 33,512 Less: present value discount ​ (8,772) Net operating lease liabilities, short-term and long-term ​ $ 24,740 ​ The Company recognizes rent expense on a straight-line basis over the non-cancellable lease term. Rent expense for the years ended December 31, 2020 and 2019 was $2.0 million and $2.1 million, respectively. Indemnification In accordance with its certificate of incorporation, bylaws and indemnification agreements, the Company has indemnification obligations to its officers and directors for certain events or occurrences, subject to certain limits, while they are serving at the Company’s request in such capacity. There have been no claims to date, and the Company has director and officer insurance to address such claims. Pursuant to agreements with clinical trial sites, the Company provides indemnification to such sites in certain conditions. Legal Proceedings In the ordinary course of business, the Company and its subsidiaries may be subject to both insured and uninsured litigation. Suits and claims may be brought against the Company by customers, suppliers, partners and/or third parties (including tort claims for personal injury arising from clinical trials of the Company’s product candidates and property damage) alleging deficiencies in performance, breach of contract, etc., and seeking resulting alleged damages. In November 2020, a purported securities class action complaint was filed in the U.S. District Court for the Eastern District of New York, putatively on behalf of all shareholders who purchased or otherwise acquired Fortress securities between December 11, 2019 and October 9, 2020 (the “Class Period”), and who were allegedly damaged in connection therewith. The case is captioned Cushman v. Fortress Biotech, Inc., et al.

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plan [Abstract]
Employee Benefit Plan	16. Employee Benefit Plan On January 1, 2008, the Company adopted a defined contribution 401(k) plan which allows employees to contribute up to a percentage of their compensation, subject to IRS limitations and provides for a discretionary Company match up to a maximum of 4% of employee compensation. For the years ended December 31, 2020 and 2019, the Company paid a matching contribution of $0.5 million and $0.4 million, respectively.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions
Related Party Transactions	17. Related Party Transactions The Company’s Chairman, President and Chief Executive Officer, individually and through certain trusts over which he has voting and dispositive control, beneficially owned approximately 9.9% and 11.6% of the Company’s issued and outstanding Common Stock as of December 31, 2020 and 2019, respectively. The Company’s Executive Vice Chairman, Strategic Development individually owns approximately 10.8% and 12.7% of the Company’s issued and outstanding Common Stock at December 31, 2020 and 2019, respectively. Shared Services Agreement with TGTX In July 2015, TGTX and the Company entered into an arrangement to share the cost of certain research and development employees. The Company’s Executive Vice Chairman, Strategic Development, is Executive Chairman and Interim Chief Executive Officer of TGTX. Under the terms of the Agreement, TGTX will reimburse the Company for the salary and benefit costs associated with these employees based upon actual hours worked on TGTX related projects. In connection with the shared services agreement, the Company invoiced TGTX $0.6 million and $0.5 million, and received payments of $0.5 million and $0.5 million for the years ended December 31, 2020 and 2019, respectively. Desk Share Agreements with TGTX and OPPM In September 2014, the Company entered into Desk Share Agreements with TGTX and Opus Point Partners Management, LLC (“OPPM”) to occupy 40% and 20% of the New York, NY office space that requires TGTX and OPPM to pay their share of the average annual rent. These initial rent allocations will be adjusted periodically for each party based upon actual percentage of the office space occupied. Additionally, the Company has reserved the right to execute desk share agreements with other third parties and those arrangements will also affect the cost of the lease actually borne by the Company. Each initial Desk Share Agreement has a term of five years. The Company took possession of the New York, NY office space in December 2015, commenced build out of the space shortly thereafter and took occupancy of the space in April 2016. The Desk Share Agreement was amended in May 2016, adjusting the initial allocations to 45% for TGTX and 10% for OPPM. The Desk Share Agreement was amended again in 2020, adjusting the rent allocations to 65% for TGTX and 0% for OPPM. In connection with the Company’s Desk Space Agreements for the New York, NY office space, for the years ended December 31, 2020 and 2019, the Company had paid $2.6 million and $2.6 million in rent, respectively, and invoiced TGTX and OPPM approximately $1.6 million and $1.3 million and nil and $0.2 million respectively, for their prorated share of the rent base. At December 31, 2020, the amount due related to this arrangement from TGTX and OPPM approximated nil and $0.4 million, respectively. As of July 1, 2018, TGTX employees began to occupy desks in the Waltham, MA office under the Desk Share Agreement. TGTX began to pay their share of the rent based on actual percentage of the office space occupied on a month by month basis. For the years ended December 31, 2020 and 2019, the Company had paid approximately $0.3 million and $0.2 million in rent for the Waltham, MA office, and invoiced TGTX approximately $0.1 million and $0.1 million, respectively. As of December 31, 2020 and 2019, the Company had paid a total of $2.9 million and $2.8 million, respectively, in rent under the Desk Share Agreements for both the New York, NY office and the Waltham, MA office combined, and invoiced TGTX approximately $1.7 million and $1.4 million, respectively, for their prorated share of the rents. Checkpoint Collaborative Agreements with TGTX Checkpoint has entered into various agreements with TGTX to develop and commercialize certain assets in connection with its licenses, including a collaboration agreement for some of the Dana Farber licensed antibodies, and a sublicense agreement for the Jubilant family of patents. Checkpoint believes that by partnering with TGTX to develop these compounds in therapeutic areas outside of its business focus, it may substantially offset its preclinical costs and milestone costs related to the development and marketing of these compounds in solid tumor indications. 2019 Notes (formerly the Opus Credit Facility) On September 14, 2016, the Company and Opus Point Health Innovations Fund (“OPHIF”) entered into a Credit Facility Agreement (the “Opus Credit Facility”). Fortress’s Chairman, President and Chief Executive Officer (Lindsay A. Rosenwald) and Fortress’s Executive Vice President, Strategic Development (Michael Weiss), are Co-Portfolio Managers and Partners of OPPM, an affiliate of OPHIF. As such, all of the disinterested directors of Fortress’s board of directors approved the terms of the Opus Credit Facility and related agreements. On March 12, 2018, the Company and OPHIF amended and restated the Opus Credit Facility (the “A&R Opus Credit Facility”). The A&R Opus Credit Facility extended the maturity date of the notes issued under the Opus Credit Facility from September 14, 2018 by one year to September 14, 2019. On September 13, 2019, the Company and OPHIF extended the maturity dates of the notes from September 14, 2019 by two years to September 14, 2021. Fortress retained the ability to prepay the Notes at any time without penalty. The notes payable under the A&R Opus Credit Facility bear interest at 12% per annum. Effective December 31, 2019, OPHIF dissolved and distributed it assets among its limited partners. Following the distribution, the $9.0 million facility comprised of separate notes (collectively, the “2019 Notes”) held by DAK Capital Inc. ($3.8 million); Fortress’ Chairman, President and Chief Executive Officer Lindsay A. Rosenwald, M.D. ($0.3 million); Fortress's Executive Vice President, Strategic Development Michael S. Weiss ($2.0 million); and various entities and individuals affiliated with Dr. Rosenwald and Mr. Weiss ($2.9 million). The terms of the 2019 Notes did not change in connection with such reallocations. During the year ended December 31, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $9.0 million balance previously outstanding under the 2019 Notes. For the year ended December 31, 2020, in connection with the 2019 Notes pay off, the Company paid $0.5 million in interest on the portion of the 2019 Notes held by the Company's Chairman, President and Chief Executive Officer and the Company's Executive Vice President, Strategic Development. 2018 Venture Notes For the year ended December 31, 2018, the Company raised approximately $21.7 million in promissory notes. National Securities Corporation (“NSC”), a wholly owned subsidiary of National, and a related party as a result of the Company’s ownership of National, acted as the sole placement agent for the 2018 Venture Notes. In November 2018, the Company announced that it had an agreement to sell its majority holding in National, the sale was completed in February of 2019, see Note 3. During the year ended December 31, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $21.7 million balance previously outstanding under the 2018 Venture Notes. 2017 Subordinated Note Financing On March 17, 2017, the Company and NSC entered into placement agency agreements with NAM Biotech Fund and NAM Special Situation Fund in connection with the sale of subordinated promissory notes (see Note 10). Pursuant to the terms of the agreements, NSC received a placement agent fee in cash of 10% of the debt raised and warrants equal to 10% of the aggregate principal amount of debt raised divided by the closing share price of the Company’s common stock on the date of closing. For the year ended December 31, 2017, NSC earned a placement agent fee of $2.8 million and a Placement Agent Warrant to purchase 716,180 shares of the Company’s common stock, all of which are outstanding, with exercise prices ranging from $3.61 to $4.75. During the year ended December 31, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $28.4 million balance previously outstanding under the 2017 Subordinated Note Financing. Avenue Credit Facility Agreement On June 12, 2020, Avenue, the Company and InvaGen entered into a Facility Agreement (“Avenue Facility Agreement”), under which, beginning on October 1, 2020, Avenue may borrow up to $2.0 million collectively from the Company and InvaGen, subject to certain conditions set forth therein. The Company’s commitment amount is $0.8 million, and InvaGen’s is $1.2 million, and a 7% per annum interest rate applies (payable on the last day of each fiscal quarter). Repayment of the loan is due upon the earliest to occur of: (i) the Second Stage Closing Date, as defined in the Avenue SPMA; (ii) April 29, 2021; and (iii) the date that is 30 days following the termination of the Avenue SPMA. As of December 31, 2020, there have been no amounts drawn by Avenue on the Avenue Facility Agreement. Founders Agreement and Management Services Agreement The Company has entered into Founders Agreements with each of the Fortress partner companies listed in the table below. Pursuant to each Founders Agreement, in exchange for the time and capital expended in the formation of each partner company and the identification of specific assets the acquisition of which result in the formation of a viable emerging growth life science company, the Company will loan each such partner company an amount representing the up-front fee required to acquire assets. Each Founders Agreement has a term of 15 years, which upon expiration automatically renews for successive one-year periods unless terminated by the Company or a Change in Control (as defined in the Founders Agreement) occurs. In connection with each Founders Agreement the Company receives 250,000 Class A Preferred shares (except for that with Checkpoint, in which the Company holds Class A Common Stock). The Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) is identical to common stock other than as to voting rights, conversion rights and the PIK Dividend right (as described below). Each share of Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) is entitled to vote the number of votes that is equal to one and one-tenth (1.1) times a fraction, the numerator of which is the sum of (A) the shares of outstanding common stock and (B) the whole shares of common stock into which the shares of outstanding Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) are convertible and the denominator of which is the number of shares of outstanding Class A Preferred Stock (Class A Common Stock with respect to Checkpoint). Thus, the Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) will at all times constitute a voting majority. Each share of Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) is convertible, at the holder’s option, into one fully paid and nonassessable share of common stock of such partner company, subject to certain adjustments. The holders of Class A Preferred Stock (and the Class A Common Stock with respect to Checkpoint), as a class, are entitled receive on each effective date or “Trigger Date” (defined as the date that the Company first acquired, whether by license or otherwise, ownership rights to a product) of each agreement (each a “PIK Dividend Payment Date”) until the date all outstanding Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) is converted into common stock or redeemed (and the purchase price is paid in full), pro rata per share dividends paid in additional fully paid and nonassessable shares of common stock (“PIK Dividends”) such that the aggregate number of shares of common stock issued pursuant to such PIK Dividend is equal to two and one-half percent (2.5%) of such partner company’s fully-diluted outstanding capitalization on the date that is one (1) business day prior to any PIK Dividend Payment Date. The Company has reached agreements with several of the partner companies to change the PIK Dividend Interest Payment Date to January 1 of each year - a change that has not and will not result in the issuance of any additional partner company common stock beyond that amount to which the Company would otherwise be entitled absent such change(s). The Company owns 100% of the Class A Preferred Stock (Class A Common Stock with respect to Checkpoint) of each partner company that has a Founders Agreement with the Company. ​ As additional consideration under the Founders Agreement, each partner company with which the Company has entered into a Founders Agreement will also: (i) pay an equity fee in shares of the common stock of such partner company, payable within five ninety The following table summarizes, by subsidiary, the effective date of the Founders Agreements and PIK dividend or equity fee payable to the Company in accordance with the terms of the Founders Agreements, Exchange Agreements and the partner companies’ certificates of incorporation. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PIK Dividend as ​ ​ ​ ​ ​ ​ a % of fully ​ ​ ​ ​ ​ ​ diluted ​ ​ ​ ​ ​ ​ outstanding ​ Class of Stock Fortress Partner Company Effective Date 1 capitalization Issued Helocyte ​ March 20, 2015 2.5 % Common Stock Avenue ​ February 17, 2015 0.0 % 2 Common Stock Mustang ​ March 13, 2015 2.5 % Common Stock Checkpoint ​ March 17, 2015 0.0 % 3 Common Stock Cellvation ​ October 31, 2016 2.5 % Common Stock Caelum ​ January 1, 2017 0.0 % 4 Common Stock Baergic ​ December 17, 2019 5 ​ 2.5 % Common Stock Cyprium ​ March 13, 2017 2.5 % Common Stock Aevitas ​ July 28, 2017 2.5 % Common Stock Oncogenuity ​ April 22, 2020 5 ​ 2.5 % Common Stock ​ Note 1: Represents the effective date of each subsidiary’s Founders Agreement. Each PIK dividend and equity fee is payable on the annual anniversary of the effective date of the original Founders Agreement or has since been amended to January 1 of each calendar year. Note 2: Pursuant to the terms of the agreement between Avenue and InvaGen Pharmaceuticals, Inc. during the term of the Avenue SPMA PIK dividends will not be paid or accrued. Note 3: Instead of a PIK dividend, Checkpoint pays the Company an annual equity fee in shares of Checkpoint’s common stock equal to 2.5% of Checkpoint’s fully diluted outstanding capitalization. Note 4: Effective January 31, 2019 the Caelum Founders Agreement and MSA with Fortress were terminated in conjunction with the execution of the DOSPA between Caelum and Alexion (See Note 4). Note 5: Represents the Trigger Date, the date that the Fortress partner company first acquires, whether by license or otherwise, ownership rights in a product. Equity Fees The following table summarizes, by subsidiary, the PIK dividend or equity fee recorded by the Company in accordance with the terms of the Founders Agreements, Exchange Agreements and the partner companies’ certificates of incorporation for the years ended December 31, 2020 and 2019 ($ in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PIK Dividend ​ Year Ended ​ Year Ended Partner company Date December 31, 2020 1 December 31, 2019 Aevitas ​ January 1 ​ $ 11 ​ $ 6 Caelum 2 January 1 ​ — ​ — Cellvation January 1 ​ 7 ​ 7 Checkpoint January 1 ​ 4,617 ​ 2,510 Cyprium January 1 ​ 711 ​ 5 Helocyte January 1 ​ 138 ​ 131 Mustang January 1 ​ 7,577 ​ 4,923 Tamid January 1 ​ — ​ 7 Fortress ​ ​ ​ (13,061) ​ (7,589) Total ​ ​ ​ $ — ​ $ — ​ Note 1: Includes 2021 PIK dividend accrued for the year ended December 31, 2020, as Type 1 subsequent event. Note 2: Pursuant to the terms of the Amended and Restated Mutual Conditional Termination Agreement between Fortress and Caelum, the Founders Agreement dated January 1, 2017 was terminated upon signing of the DOSPA with Alexion on January 30, 2019. Management Services Agreements The Company has entered into Management Services Agreements (the “MSAs”) with certain of its partner companies. Pursuant to each MSA, the Company’s management and personnel provide advisory, consulting and strategic services to each partner company that has entered into an MSA with Fortress for a period of five ​ The following table summarizes, by partner company, the effective date of the MSA and the annual consulting fee payable by the subsidiary to the Company in quarterly installments ($ in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Fortress partner company Effective Date 2020 2019 Helocyte ​ March 20, 2015 ​ $ 500 ​ $ 500 Avenue 1 ​ February 17, 2015 ​ — ​ — Mustang ​ March 13, 2015 ​ 500 ​ 500 Checkpoint ​ March 17, 2015 ​ 500 ​ 500 Cellvation ​ October 31, 2016 ​ 500 ​ 500 Baergic ​ March 9, 2017 ​ 500 ​ 500 Cyprium ​ March 13, 2017 ​ 500 ​ 500 Aevitas ​ July 28, 2017 ​ 500 ​ 500 Tamid 2 ​ November 30, 2017 ​ — ​ 500 Oncogenuity 3 ​ February 10, 2017 ​ ​ 500 ​ ​ — Fortress - MSA Income ​ ​ ​ (4,000) ​ (4,000) Consolidated (Income)/Expense ​ ​ ​ $ — ​ $ — ​ Note 1: Pursuant to the terms of the agreement between Avenue and InvaGen Pharmaceuticals, Inc. during the term of the Avenue SPMA fees under the MSA will not be due or accrued. Note 2: In December 2019, Tamid discontinued development and terminated its’ licenses and clinical trial agreements with UNC. Note 3: Oncogenuity license was purchased in the year ended December 31, 2020. ​ Fees and Stock Grants Received by Fortress Fees recorded in connection with the Company’s agreements with its subsidiaries are eliminated in consolidation. These include management services fees, issuance of common shares of partner companies in connection with third party raises and annual stock dividend or issuances on the anniversary date of respective Founders Agreements.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2020
Income taxes
Income taxes	​ ​ ​ ​ ​ ​ ​ 18. Income Taxes Deferred income taxes reflect the net tax effects of (a) temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, and (b) operating losses and tax credit carryforwards. The components of the income tax provision (benefit) are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 Current ​ ​ ​ ​ Federal ​ $ — ​ $ — State ​ 136 ​ — Deferred ​ ​ Federal ​ — ​ — State ​ — ​ — Total ​ $ 136 ​ $ — ​ For the years ended December 31, 2020 and 2019, income tax expense was $0.1 million and nil, respectively, resulting in an effective income tax rate of 0.13% and 0%. The increase in income tax expense in 2020 is due to additional state tax return filings. The Company has incurred net operating losses since inception. The Company has not reflected any benefit of such net operating loss carryforwards (“NOL”) in the accompanying consolidated financial statements and has established a valuation allowance of $203.9 million against its net deferred tax assets. Deferred income taxes reflect the net tax effects of (a) temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes, and (b) operating losses and tax credit carryforwards. The significant components of the Company’s deferred taxes consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ($ in thousands) ​ 2020 ​ 2019 Deferred tax assets: ​ ​ Net operating loss carryforwards ​ $ 152,295 ​ $ 125,657 Amortization of license fees ​ 20,628 ​ 17,077 Amortization of in-process R&D ​ 415 ​ 449 Stock compensation ​ 14,732 ​ 13,280 Lease liability ​ 7,306 ​ 7,454 Accruals and reserves ​ 1,570 ​ 1,810 Tax credits ​ 16,326 ​ 12,716 Startup costs ​ 54 ​ 58 Unrealized gain/loss on investments ​ 1,075 ​ 716 State taxes ​ 41 ​ — Reserve on Sales Return, Discount and Bad Debt ​ ​ 1,455 ​ ​ — Total deferred tax assets ​ 215,897 ​ 179,217 Less: valuation allowance ​ (203,930) ​ (168,223) Net deferred tax assets ​ $ 11,967 ​ $ 10,994 ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities: ​ ​ Right of use asset ​ $ (6,050) ​ $ (6,280) Fair Value adjustment on investment in Caelum ​ (4,804) ​ ​ (2,879) Basis in subsidiary ​ (1,113) ​ (1,835) Total deferred tax assets, net ​ $ — ​ $ — ​ A reconciliation of the statutory tax rates and the effective tax rates is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ​ 2020 2019 Percentage of pre-tax income: ​ ​ ​ U.S. federal statutory income tax rate 21 % 21 % State taxes, net of federal benefit 11 % 12 % Credits 4 % 3 % Non-deductible items (1) % — % Provision to return 1 % 1 % Stock based compensation shortfall (1) % (1) % Change in state rate — % 3 % Deconsolidation of Caelum — % (3) % Change in valuation allowance (35) % (36) % Change in subsidiary basis 1 % (1) % Other (1) % 1 % Effective income tax rate — % — % ​ ​ The Company files a consolidated income tax return with subsidiaries for which the Company has an 80% or greater ownership interest. subsidiaries for which the Company does not have an 80% or more ownership are not included in the Company’s consolidated income tax group and file their own separate income tax return. As a result, certain corporate entities included in these financial statements are not able to combine or offset their taxable income or losses with other entities’ tax attributes. ASC 740 requires a valuation allowance to reduce the deferred tax assets reported if, based on the weight of all positive and negative evidence, it is more likely than not that some portion, or all, of the deferred tax assets will not be realized. Realization of the deferred tax assets is substantially dependent on the Company’s ability to generate sufficient taxable income within certain future periods. Management has considered the Company’s history of cumulative tax and book losses incurred since inception, and the other positive and negative evidence, and has concluded that it is more likely than not that the Company will not realize the benefits of the net deferred tax assets as of December 31, 2020 and 2019. Accordingly, a full valuation allowance has been established against the net deferred tax assets as of December 31, 2020 and 2019. The valuation allowance increased by a net $35.7 million during the current year. The Company has incurred net operating losses (“NOLs”) since inception. At December 31, 2020, the Company had federal NOLs of $525.7 million, which will begin to expire in the year 2026 2022 2028 As of December 31, 2020, th Company had no unrecognized tax benefits and does not anticipate any significant change to the unrecognized tax benefit balance. The Company would classify interest and penalties related to uncertain tax positions as income tax expense, if applicable. There was no interest expense or penalties related to unrecognized tax benefits recorded through December 31, 2020. The NOLs from tax years 2008 through 2019 remain open to examination (and adjustment) by the Internal Revenue Service and state taxing authorities. In addition, federal tax years ending December 31, 2017, 2018 and 2019 are open for assessment of federal taxes. The expiration of the statute of limitations related to the various state income and franchise tax returns varies by state. In January 2019, in connection with the Alexion DOSPA, the Company ceased to consolidate Caelum (see Note 4). As a result of the deconsolidation of Caelum, the Company has eliminated Caelum’s deferred tax assets and the valuation allowance for a net tax expense charge or benefit of zero for the year ended December 31, 2019. Coronavirus Aid, Relief and Economic Security Act ("CARES Act") In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act ("CARES Act") was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to refundable payroll tax credits, deferment of employer's social security payments, net operating loss utilization and carryback periods and modifications to the net interest deduction limitations. The CARES Act did not have a material impact on the Company’s income tax provision for 2020. The Company will continue to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. ​ On December 27, 2020, the President of the United States signed the Consolidated Appropriations Act, 2021 (“Consolidated Appropriations Act”) into law. The Consolidated Appropriations Act is intended to enhance and expand certain provisions of the CARES Act, allows for the deductions of expenses related to the Paycheck Protection Program funds received by companies, and provides an update to meals and entertainment expensing for 2021. The Consolidated Appropriations Act did not have a material impact to the Company’s income tax provision for 2020. ​

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Information
Segment Information	19. Segment Information The Company operates in two reportable segments, Dermatology Product Sales and Pharmaceutical and Biotechnology Product Development. The accounting policies of the Company’s segments are the same as those described in Note 2. The following tables summarize, for the periods indicated, operating results from continued operations by reportable segment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmaceutical ​ ​ ​ ​ ​ ​ ​ and ​ ​ ​ ​ ​ Dermatology ​ Biotechnology ​ ​ ​ ($ in thousands) ​ Products ​ Product ​ ​ ​ Year Ended December 31, 2020 Sales Development Consolidated Net revenue ​ $ 44,531 ​ $ 1,068 ​ $ 45,599 Direct cost of goods ​ (14,594) ​ — ​ (14,594) Sales and marketing costs ​ (17,384) ​ — ​ (17,384) Research and development ​ — ​ (64,109) ​ (64,109) General and administrative ​ ​ (4,716) ​ ​ (39,066) ​ ​ (43,782) Other expense ​ (697) ​ (7,882) ​ (8,579) Income tax expense ​ ​ (96) ​ ​ (40) ​ ​ (136) Segment income (loss) ​ $ 7,044 ​ $ (110,029) ​ $ (102,985) Segment assets ​ ​ ​ ​ ​ ​ ​ ​ ​ Intangible assets, net ​ ​ 14,629 ​ ​ — ​ ​ 14,629 Tangible assets ​ ​ 30,843 ​ ​ 283,362 ​ ​ 314,205 Total segment assets ​ $ 45,472 ​ $ 283,362 ​ $ 328,834 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmaceutical ​ ​ ​ ​ ​ ​ ​ ​ and ​ ​ ​ ​ ​ Dermatology ​ Biotechnology ​ ​ ​ ($ in thousands) ​ Products ​ Product ​ ​ ​ Year Ended December 31, 2019 Sales Development Consolidated Net revenue ​ $ 34,921 ​ $ 1,708 ​ $ 36,629 Direct cost of goods ​ (10,532) ​ — ​ (10,532) Sales and marketing costs ​ (17,120) ​ — ​ (17,120) Research and development ​ — ​ (81,326) ​ (81,326) General and administrative ​ (2,556) ​ (35,914) ​ (38,470) Other income ​ — ​ 9,159 ​ 9,159 Segment income (loss) ​ $ 4,713 ​ $ (106,373) ​ $ (101,660) Segment assets ​ ​ ​ ​ ​ ​ ​ ​ ​ Intangible assets, net ​ 7,377 ​ ​ — ​ ​ 7,377 Tangible assets ​ 19,946 ​ ​ 199,099 ​ ​ 219,045 Total segment assets ​ $ 27,323 ​ $ 199,099 ​ $ 226,422 ​

Revenues from Contracts and Sig

Revenues from Contracts and Significant Customers	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenues from Contracts and Significant Customers	20. Revenues from Contracts and Significant Customers Disaggregation of Total Revenues The Company has five marketed products, Targadox®, Ximino®, Exelderm®, Luxamend® and Ceracade®. Substantially all of the Company’s product revenues are recorded in the U.S. Substantially all of the Company’s collaboration revenues are from its collaboration with TGTX. ​ The table below summarizes the Company’s revenue for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ($ in thousands) 2020 2019 Revenue ​ ​ ​ ​ ​ ​ ​ Product revenue, net ​ $ 44,531 ​ $ 34,921 ​ Revenue – related party ​ 1,068 ​ 1,708 ​ Net revenue ​ $ 45,599 ​ $ 36,629 ​ ​ Significant Customers For the year ended December 31, 2020, none of the Company’s Dermatology Products customers accounted for more than 10.0% of its total gross product revenue. For the year ended December 31, 2019, two of the Company’s Dermatology Products customers each accounted for more than 10.0% of its total gross product revenue, accounting for approximately 50% and 10%, respectively. The revenue from these customers is captured in the product revenue, net line item within the Consolidated Statements of Operations. At December 31, 2020, one of the Company’s Dermatology Products customers accounted for 12% of its total accounts receivable balance. At December 31, 2019, two of the Company’s Dermatology Products customers accounted for more than 10% of its total accounts receivable balance at 21% and 18%, respectively. Included in Product revenue, net, for the years ended December 31, 2020 and 2019 was $1.4 million and nil, respectively, of revenue that was constrained in a prior period. ​ Revenue – related party represents collaboration revenue from TGTX in connection with Checkpoint.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	21. Subsequent Events Cyprium ​ On February 24, 2021, Cyprium announced the execution of an asset purchase agreement with Sentynl Therapeutics, Inc. (“Sentynl”), a U.S.-based specialty pharmaceutical company owned by the Zydus Group. The asset purchase agreement commits Sentynl to an upfront cash payment to Cyprium of $8.0 million for development, a $3.0 million cash milestone payment at NDA acceptance, the purchase price of $9.0 million, as well as potential sales milestones totaling $255.0 million. Royalties on CUTX-101 net sales range from the mid-single digits up to the mid-twenties are also payable. Cyprium will retain development responsibility of CUTX-101 through approval of the NDA by the FDA, and Sentynl will be responsible for commercialization of CUTX-101 as well as progressing newborn screening activities. Continued development of CUTX-101 will be overseen by a Joint Steering Committee consisting of representatives from Cyprium and Sentynl. Cyprium will retain 100% ownership over any FDA priority review voucher that may be issued at NDA approval for CUTX-101. ​ ​ Avenue ​ On February 12, 2021, Avenue resubmitted its NDA to the FDA for IV Tramadol. The NDA for IV Tramadol was resubmitted following the receipt of official minutes from a Type A meeting with the FDA, which was conducted following a CRL issued by the FDA in October 2020. The resubmission included revised language relating to the proposed product label and a report relating to terminal sterilization validation. On February 26, 2021, Avenue received an acknowledgement letter from the FDA that Avenue’s resubmission of its NDA is a complete, class 1 response to the CRL, and a Prescription Drug User Fee Act goal date has been set for April 12, 2021. ​ Journey ​ 8% Cumulative Convertible Class A Preferred Offering ​ In March 2021, our partner company Journey is conducting an offering to accredited investors of 8% Cumulative Convertible Class A Preferred Stock in an aggregate minimum amount of $12.5 million and an aggregate maximum amount of $30.0 million, which may be increased if Journey and the placement agent agree to do so. Dividends on the Journey preferred stock will be paid quarterly in shares of the Company’s common based upon a 7.5% discount to the average trading price over the 10-day period preceding the dividend payment date. The approximate number of shares issuable as a dividend per quarter, based upon the Company’s common stock price as of March 26, 2021, would be 72,849 shares if the minimum amount is raised and 174,838 if the maximum amount is raised. ​ In addition, if the Journey preferred stock has not been converted into Journey common stock upon a sale of Journey or a financing of Journey in an amount of at least $25.0 million within a year of the closing (extendable by another six months at Journey’s option), the Journey preferred stock will be exchanged for shares of the Company’s common stock, also based upon a 7.5% discount to the average Company common stock trading price over the 10-day period preceding such exchange. The approximate number of the Company’s common shares issuable upon such exchange would be approximately 3.4 million shares if the minimum amount is sold and 8.1 million if the maximum amount is sold, in each case based upon the Company’s common stock price as of March 26, 2021. The Company will be obligated to file one or more registration statements covering the issuance of shares that result from such dividends/exchange. As consideration for the foregoing Journey will issue to the Company additional shares of Journey common stock, debt securities, or a combination of the foregoing. From the initial closing on March 31, 2021, the Company raised gross proceeds of $12.5 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”). The Company’s consolidated financial statements include the accounts of the Company and the accounts of the Company’s subsidiaries, listed above. All intercompany balances and transactions have been eliminated. The accompanying consolidated financial statements include the accounts of the Company’s subsidiaries. For consolidated entities where the Company owns less than 100% of the subsidiary, the Company records net loss attributable to non-controlling interests in its consolidated statements of operations equal to the percentage of the economic or ownership interest retained in such entities by the respective non-controlling parties. The Company also consolidates subsidiaries in which it owns less than 50% of the subsidiary but maintains voting control. The Company continually assesses whether changes to existing relationships or future transactions may result in the consolidation or deconsolidation of partner companies.
Use of Estimates	Use of Estimates The Company’s consolidated financial statements include certain amounts that are based on management’s best estimates and judgments. The Company’s significant estimates include, but are not limited to, useful lives assigned to long-lived assets, fair value of stock options and warrants, stock-based compensation, common stock issued to acquire licenses, investments, accrued expenses, provisions for income taxes and contingencies. Due to the uncertainty inherent in such estimates, actual results may differ from these estimates.
Revenue Recognition	Revenue Recognition The Company recognizes revenue under Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers Step 1: Identify the contract with the customer Step 2: Identify the performance obligations in the contract Step 3: Determine the transaction price Step 4: Allocate the transaction price to the performance obligations in the contract Step 5: Recognize revenue when the company satisfies a performance obligation In order to identify the performance obligations in a contract with a customer, a company must assess the promised goods or services in the contract and identify each promised good or service that is distinct. A performance obligation meets ASC 606’s definition of a “distinct” good or service (or bundle of goods or services) if both of the following criteria are met: The customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct). The entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract). If a good or service is not distinct, the good or service is combined with other promised goods or services until a bundle of goods or services is identified that is distinct. The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The transaction price is allocated to each performance obligation on a relative standalone selling price basis. The transaction price allocated to each performance obligation is recognized when that performance obligation is satisfied, at a point in time or over time as appropriate. The Company recognizes product revenue from sales of Ximino®, Targadox®, Exelderm®, Luxamend® and Ceracade®. The Company’s performance obligation to deliver products is satisfied at the point in time that the goods are delivered to the customer, which is when the customer obtains title to and has the risks and rewards of ownership of the products. The Company has variable consideration in the form of rights of return, coupons, and price protection to customers. The Company uses an expected value method to estimate variable consideration and whether the transaction price is constrained. Payment is due within months of when the customer is invoiced, with discounts for prompt payment. The Company recorded expense related to returns reserve of $1.3 million and $2.9 million for the years ended December 31, 2020 and December 31, 2019, respectively. Because the Company’s agreements for sales of product to its distributors can be cancelled early, prior to the termination date, they are deemed to have an expected duration of one year or less, and as such, the Company has elected the practical expedient in ASC 606-10-50-14(a) to not disclose information about its remaining performance obligations.
Discontinued Operations	Discontinued Operations Pursuant to the discontinued operations criteria set forth in ASC Subtopic 205-20-45, Presentation of Financial Statements
Fair Value Measurement	Fair Value Measurement The Company follows accounting guidance on fair value measurements for financial assets and liabilities measured at fair value on a recurring basis. Under the accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance requires fair value measurements be classified and disclosed in one of the following three categories: Level 1 Level 2 Level 3 : Unobservable inputs which are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability. Certain of the Company’s financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as accounts payable, accrued expenses and other current liabilities.
Segment Reporting	Segment Reporting The Company operates in two operating and reportable
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Cash and cash equivalents at December 31, 2020 and at December 31, 2019 consisted of cash and certificates of deposit in institutions in the United States. Balances at certain institutions have exceeded Federal Deposit Insurance Corporation insured limits and U.S. government agency securities.
Short-term Investments	Short-term Investments The Company classifies its certificates of deposit as cash and cash equivalents or held to maturity in accordance with ASC 320, Investments - Debt and Equity Securities At December 31, 2020, the Company had approximately $76.8 million and $15.0 million, respectively, in certificates of deposit, which the Company classified as cash and cash equivalents. There were no short term investments classified as held-to-maturity as of December 31, 2020.
Property and Equipment	Property and Equipment Computer equipment, furniture & fixtures and machinery & equipment are recorded at cost and depreciated using the straight-line method over the estimated useful life of each asset. Leasehold improvements are amortized over the shorter of the estimated useful lives or the term of the respective leases. In connection with Mustang’s cell processing facility, Mustang incurred costs for the design and construction of the facility and the purchase of equipment; $0.5 million and $1.2 million are recorded in fixed assets – construction in process on the balance sheet at December 31, 2020 and 2019, respectively. Upon completion of the facility’s construction, all costs associated with the buildout will be recorded as leasehold improvements and amortized over the shorter of the estimated useful lives or the term of the respective leases, upon the improvement being placed in service.
Restricted Cash	Restricted Cash The Company records cash held in trust or pledged to secure certain debt obligations as restricted cash. As of December 31, 2020, the Company had $1.6 million of restricted cash representing pledges to secure letters of credit in connection with certain office leases. As of December 31, 2019, the Company had $16.6 million of restricted cash collateralizing a note payable of $15.0 million and $1.6 million in certain pledges to secure letters of credit in connection with certain office leases. The following table provides a reconciliation of cash, cash equivalents, and restricted cash from the consolidated balance sheets to the consolidated statements of cash flows for the years ended 2020, and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ($ in thousands) ​ 2020 ​ 2019 Cash and cash equivalents $ 233,351 $ 136,858 Restricted cash ​ 1,645 ​ 16,574 Total cash and cash equivalents and restricted cash ​ $ 234,996 ​ $ 153,432
Inventories	Inventories Inventories comprise finished goods, which are valued at the lower of cost and net realizable value, on a first-in, first-out basis. The Company evaluates the carrying value of inventories on a regular basis, taking into account anticipated future sales compared with quantities on hand, and the remaining shelf life of goods on hand.
Accounts Receivable, Net	Accounts Receivable, net Accounts receivable consists of amounts due to the Company for product sales of JMC. The Company’s accounts receivable reflects discounts for estimated early payment and for product estimated returns. Accounts receivable are stated at amounts due from customers, net of an allowance for doubtful accounts that are outstanding longer than the contractual payment terms are considered past due. The Company determines its allowance for doubtful accounts by considering a number of factors, including the length of time trade accounts receivable are past due and the customer’s current ability to pay its obligation to the Company. The Company writes off accounts receivable when they become uncollectible. For the years ended December 31, 2020 and 2019 the allowance for doubtful accounts was approximately $0.1 million and $0.1 million, respectively. The allowance for product estimated returns were $4.6 million and $5.4 million at December 31, 2020 and 2019, respectively, representing constrained revenue.
Investments at Fair Value	Investments at Fair Value The Company elects the fair value option for its long-term investments at fair value (see Note 6). The decision to elect the fair value option, which is irrevocable once elected, is determined on an instrument by instrument basis and applied to an entire instrument. The net gains or losses, if any, on an investment for which the fair value option has been elected are recognized as a change in fair value of investments on the Consolidated Statements of Operations. The Company has various processes and controls in place to ensure that fair value is reasonably estimated. While the Company believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different estimate of fair value at the reporting date.
Accounting for Warrants at Fair Value	Accounting for Warrants at Fair Value The Company classifies as liabilities any contracts that (i) require net-cash settlement (including a requirement to net-cash settle the contract if an event occurs and if that event is outside the control of the Company) or (ii) give the counterparty a choice of net-cash settlement or settlement in shares (physical settlement or net-share settlement). The accounting treatment of derivative financial instruments requires that the Company record the warrants at their fair values as of the inception date of the agreement and at fair value as of each subsequent balance sheet date. Any change in fair value is recorded as non-operating, non-cash income or expense for each reporting period at each balance sheet date. The Company reassesses the classification of its derivative instruments at each balance sheet date. If the classification changes as a result of events during the period, the contract is reclassified as of the date of the event that caused the reclassification. The Company assessed the classification of warrants issuable in connection with 2018 Venture Notes and determined that the Cyprium Contingently Issuable Warrants met the criteria for liability classification. Accordingly, the Company classified the Cyprium Contingently Issuable Warrants as a liability at their fair value and adjusted the instruments to fair value at each balance sheet date until the warrants were issued. Any change in the fair value of the Cyprium Contingently Issuable Warrants is recognized as “change in the fair value of derivative liabilities” in the Consolidated Statements of Operations. During the year ended December 31, 2020, Cyprium raised approximately $8.0 million in Cumulative Redeemable Perpetual Preferred Shares (“Cyprium Offering,” see Note 14). The Cyprium Offering coupled with the repayment of the 2018 Venture Debt (see Note 10), triggered the issuance of the Cyprium Warrant, in that a price per share could be established. As such these events resulted in Cyprium recording the Cyprium Warrant as issued rather than contingently issuable.
Opus Credit Facility, with Detachable Warrants	Opus Credit Facility, with Detachable Warrants The Company accounted for the Opus Credit Facility (see Note 10) with detachable warrants in accordance with ASC 470, Debt The Company recorded the related issue costs and value ascribed to the warrants as a debt discount of the Opus Credit Facility. The discount was amortized utilizing the effective interest method over the term of the Opus Credit Facility. The unamortized discount, if any, upon repayment of the Opus Credit Facility would be expensed to interest expense. In accordance with ASC Subtopic 470-20, the Company determined the weighted average effective interest rate of the debt was approximately 16% at December 31, 2019. The Company also evaluated the Opus Credit Facility and warrants in accordance with the provisions of ASC 815, Derivatives and Hedging As of December 31, 2019, Opus dissolved and distributed its assets among its Limited Partners. The dissolution did not impact any of the terms under the Opus Credit Facility. During the year ended December 31, 2020, the Company used certain proceeds from the Oaktree Note to pay off the $9.0 million balance previously outstanding under the Opus Credit Facility/2019 Notes (see Note 10).
Issuance of Debt and Equity	Issuance of Debt and Equity The Company issues complex financial instruments which include both equity and debt features. The Company analyzes each instrument under ASC 480, Distinguishing Liabilities from Equity, Derivatives and Hedging Debt The Company accounted for the Oaktree Note with detachable warrants in accordance with ASC 470, Debt The Company recorded the related issue costs and value ascribed to the warrants as a debt discount of the Oaktree Note. The discount was amortized utilizing the effective interest method over the term of the Oaktree Note. The unamortized discount, if any, upon repayment of the Oaktree Note would be expensed to interest expense. In accordance with ASC Subtopic 470-20, the Company determined the weighted average effective interest rate of the debt was approximately 15.13% at December 31, 2020. The Company also evaluated the Oaktree Note and warrants in accordance with the provisions of ASC 815, Derivatives and Hedging
Long-Lived Assets	Long-Lived Assets Long-lived assets, primarily fixed assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the assets might not be recoverable. The Company will perform a periodic assessment of assets for impairment in the absence of such information or indicators. Conditions that would necessitate an impairment assessment include a significant decline in the observable market value of an asset, a significant change in the extent or manner in which an asset is used, or a significant adverse change that would indicate that the carrying amount of an asset or group of assets is not recoverable. For long-lived assets to be held and used, the Company would recognize an impairment loss only if its carrying amount is not recoverable through its undiscounted cash flows and measures the impairment loss based on the difference between the carrying amount and estimated fair value. As of December 31, 2020 and 2019 there were no indicators of impairment.
Research and Development	Research and Development Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Upfront and milestone payments due to third parties that perform research and development services on the Company’s behalf will be expensed as services are rendered or when the milestone is achieved. Research and development costs primarily consist of personnel related expenses, including salaries, benefits, travel, and other related expenses, stock-based compensation, payments made to third parties for license and milestone costs related to in-licensed products and technology, payments made to third party contract research organizations for preclinical and clinical studies, investigative sites for clinical trials, consultants, the cost of acquiring and manufacturing clinical trial materials, and costs associated with regulatory filings, laboratory costs and other supplies. In accordance with ASC 730-10-25-1, Research and Development
Contingencies	Contingencies The Company records accruals for contingencies and legal proceedings expected to be incurred in connection with a loss contingency when it is probable that a liability has been incurred and the amount can be reasonably estimated. If a loss contingency is not probable but is reasonably possible, or is probable but cannot be estimated, the nature of the contingent liability, together with an estimate of the range of possible loss if determinable and material, would be disclosed.
Leases	Leases Effective January 1, 2019, the Company accounts for its leases under ASC 842, Leases In calculating the right-of-use asset and lease liability, the Company elects to combine lease and non-lease components. The Company continues to account for leases in the prior period consolidated financial statements under ASC Topic 840, Leases
Stock-Based Compensation	Stock-Based Compensation The Company expenses stock-based compensation to employees and non-employees over the requisite service period based on the estimated grant-date fair value of the awards and forfeitures, which are recorded upon occurence. For stock-based compensation awards to non-employees, prior to the adoption of ASU 2018-07 on January 1, 2019, the Company remeasured the fair value of the non-employee awards at each reporting period prior to vesting and finally at the vesting date of the award. Changes in the estimated fair value of these non-employee awards were recognized as compensation expense in the period of change. Subsequent to the adoption of ASU 2018-07, the Company recognizes non-employees compensation costs over the requisite service period based on a measurement of fair value for each stock award at the time the award is granted. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment.
Income Taxes	Income Taxes The Company accounts for income taxes under ASC 740, Income Taxes ASC 740 also clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements and prescribes a recognition threshold and measurement process for financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more-likely-than-not to be sustained upon examination by taxing authorities. ASC 740 also provides guidance on de-recognition, classification, interest and penalties, accounting in interim period, disclosure and transition. Based on the Company’s evaluation, it has been concluded that there are no significant uncertain tax positions requiring recognition in the Company’s financial statements. The 2017 through 2019 tax years are the only periods subject to examination upon filing of appropriate tax returns. The Company believes that its income tax positions and deductions would be sustained on audit and does not anticipate any adjustments that would result in a material change to its financial position. The Company’s policy for recording interest and penalties associated with audits is to record such expense as a component of income tax expense. There were no amounts accrued for penalties or interest as of or during the years ended December 31, 2020 and 2019. Management is currently unaware of any issues under review that could result in significant payments, accruals or material deviations from its position.
Non-Controlling Interests	Non-Controlling Interests Non-controlling interests in consolidated entities represent the component of equity in consolidated entities held by third parties. Any change in ownership of a subsidiary while the controlling financial interest is retained is accounted for as an equity transaction between the controlling and non-controlling interests.
Comprehensive Loss	Comprehensive Loss The Company’s comprehensive loss is equal to its net loss for all periods presented.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820), - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement In June 2018, the FASB issued ASU 2018-07, “Improvements to Nonemployee Share-Based Payment Accounting” In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480) and Derivatives and Hedging (Topic 815): I. Accounting for Certain Financial Instruments with Down Round Features; II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Leases (Topic 842): Targeted Improvements Recent Accounting Pronouncements “Financial Instruments – Credit Losses” In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. The Company adopted the new guidance in the first quarter of 2021 and the adoption of this guidance did not to have a material impact on the financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Summary of Significant Accounting Policies
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash from the consolidated balance sheets to the consolidated statements of cash flows for the years ended 2020, and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ($ in thousands) ​ 2020 ​ 2019 Cash and cash equivalents $ 233,351 $ 136,858 Restricted cash ​ 1,645 ​ 16,574 Total cash and cash equivalents and restricted cash ​ $ 234,996 ​ $ 153,432

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2020
Discontinued Operations
Schedule of Cash Flows Statement	The table below depicts the cash flows from the transaction for the year ended December 31, 2019: ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ December 31, ($ in thousands) 2019 Investing activities ​ Proceeds from sale of National ​ $ 13,089 Total cash provided by discontinued investing activities ​ $ 13,089

Collaboration and Stock Purch_2

Collaboration and Stock Purchase Agreements (Tables)	12 Months Ended
	Dec. 31, 2020
Collaboration and Stock Purchase Agreements
Schedule of Assets and Liabilities of Caelum	The Company deconsolidated its holdings in Caelum immediately prior to the execution of the DOSPA. Following the DOSPA execution, the Company owns approximately 40% of the issued and outstanding capital stock of Caelum. The following table provides a summary of the assets and liabilities of Caelum impacted by the deconsolidation: ​ ​ ​ ​ ​ ​ ​ January ($ in thousands) 2019 ASSETS ​ Current assets ​ Cash and cash equivalents ​ $ 1,201 Prepaid expenses and other current assets ​ 6 Total current assets ​ $ 1,207 ​ ​ ​ ​ LIABILITIES ​ Current liabilities ​ Accounts payable and accrued expenses ​ $ 2,246 Interest payable ​ 198 Interest payable - related party ​ 106 Note payable - related party ​ 929 Note payable ​ 9,914 Warrant liability ​ 991 Total current liabilities ​ 14,384 Net liability impacted by deconsolidation ​ $ 13,177
Schedule of Gain from Deconsolidation of Caelum	In connection with this transaction the Company recorded a gain resulting from the deconsolidation of Caelum on its consolidated financial statements for the year ended December 31, 2019: ​ ​ ​ ​ ​ ​ ​ Gain on ​ ​ deconsolidation of ($ in thousands) Caelum Fair value of Caelum ​ $ 11,148 Net liabilities deconsolidated ​ 13,177 Non-controlling interest share ​ (4,849) Write off of MSA fees due Fortress ​ (1,000) Gain on deconsolidation of Caelum ​ $ 18,476

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property and Equipment
Schedule of Property and Equipment	Fortress’ property and equipment consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Useful Life December 31, December 31, ($ in thousands) ​ (Years) ​ 2020 ​ 2019 Computer equipment ​ 3 ​ $ 663 ​ $ 648 Furniture and fixtures ​ 5 ​ 1,199 ​ 1,162 Machinery & equipment ​ 5 ​ 5,748 ​ 4,594 Leasehold improvements ​ 2-15 ​ 10,580 ​ 9,358 Construction in progress 1 ​ N/A ​ 499 ​ 1,157 Total property and equipment ​ ​ ​ ​ 18,689 ​ 16,919 Less: Accumulated depreciation ​ ​ ​ ​ (6,766) ​ (4,486) Property and equipment, net ​ ​ ​ ​ $ 11,923 ​ $ 12,433 ​ Note 1: Relates to the Mustang cell processing facility.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Schedule of Financial Instruments, Measured at Fair Value on a Recurring Basis	The following tables classify into the fair value hierarchy of Fortress’ financial instruments, measured at fair value on a recurring basis on the Consolidated Balance Sheets as of December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement as of December 31, 2020 ($ in thousands) Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ Fair value of investment in Caelum ​ $ — ​ $ — ​ $ 17,566 ​ $ 17,566 Total ​ $ — ​ $ — ​ $ 17,566 ​ $ 17,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement as of December 31, 2019 ($ in thousands) Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ Fair value of investment in Caelum $ — $ — $ 11,148 $ 11,148 Total $ — $ — $ 11,148 $ 11,148 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurement as of December 31, 2019 ($ in thousands) Level 1 Level 2 Level 3 Total Liabilities ​ ​ ​ ​ Warrant liabilities $ — $ — $ 27 $ 27 Total $ — $ — $ 27 $ 27
Roll Forward of the Changes in Fair Value of Level 3 Financial Instruments	The table below provides a roll forward of the changes in fair value of Level 3 financial instruments for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment in ​ ​ Warrant ​ ​ ​ ($ in thousands) Caelum Liabilities Total Balance at December 31, 2019 ​ $ 11,148 ​ $ 27 ​ $ 11,175 Change in fair value ​ ​ — ​ ​ 1,189 ​ ​ 1,189 Reclass partner company's warrants from liability to equity ​ ​ — ​ ​ (1,216) ​ ​ (1,216) Change in fair value of investments ​ ​ 6,418 ​ ​ — ​ ​ 6,418 Balance at December 31, 2020 ​ $ 17,566 ​ $ — ​ $ 17,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investment ​ Caelum Convertible Warrants ​ ​ ($ in thousands) in Caelum ​ ​ Notes ​ liabilities Total Balance at December 31, 2018 ​ $ — ​ $ 9,914 ​ $ 991 ​ $ 10,905 Conversion of convertible notes ​ — ​ (9,914) ​ — ​ (9,914) Issuance of warrant ​ — ​ — ​ (991) ​ (991) Fair value of investment ​ 11,148 ​ — ​ — ​ 11,148 Change in fair value of derivative liability ​ — ​ — ​ 27 ​ 27 Balance at December 31, 2019 ​ $ 11,148 ​ $ — ​ $ 27 ​ $ 11,175
Cyprium [Member]
Roll Forward of the Changes in Fair Value of Level 3 Financial Instruments	​ ​ ​ ​ ​ ​ ​ Cyprium ​ ​ Contingently ​ ​ Issuable Warrant ($ in thousands) ​ Liability Beginning balance at January 1, 2019 ​ $ — Change in fair value ​ ​ 27 Ending balance at December 31, 2019 ​ $ 27 Change in fair value ​ ​ 1,189 Reclass partner company's warrants from liability to equity ​ ​ (1,216) Ending balance at December 31, 2020 ​ $ —
Warrants [Member] | Caelum [Member]
Summary of the Weighted average Significant Unobservable Inputs	The fair value of Caelum's warrant liability, which was issued in connection with Caelum’s convertible note, was written up to the full value of the liability prior to the conversion of the notes in January 2019 (see Note 10). The fair value was measured using a Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Caelum’s warrant liabilities that are categorized within Level 3 of the fair value hierarchy as of January 2019 was as follows: ​ ​ ​ ​ ​ ​ January ​ 2019 Risk-free interest rate 2.905% - 2.909 % Expected dividend yield — % Expected term in years 3.84 - 3.96 ​ Expected volatility 70 %
Fair Value of Liabilities Measured on Recurring Basis	​ ​ ​ ​ ​ ​ ​ Fair Value of ​ ​ Derivative ​ ​ Warrant ($ in thousands) Liability Beginning balance at January 1, 2019 ​ $ 991 Issuance of warrant due to conversion of note ​ (991) Ending balance at December 31, 2019 ​ $ —
Warrants [Member] | Cyprium [Member]
Summary of the Weighted average Significant Unobservable Inputs	The fair value of the Cyprium Contingently Issuable Warrants in connection with the 2018 Venture Debt was determined by applying management’s estimate of the probability of issuance of the Contingently Issuable Warrants together with an option-pricing model, with the following key assumptions: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2020 ​ 2019 Risk-free interest rate 0.69 % 1.92 % Expected dividend yield — — ​ Expected term in years 10.0 10 ​ Expected volatility 85 % 93 % Probability of issuance of the warrant 100 % 5 %
Convertible Notes [Member] | Caelum [Member]
Summary of the Weighted average Significant Unobservable Inputs	Caelum’s convertible debt was measured at fair value using the Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Caelum’s convertible debt that is categorized within Level 3. As of December 31, 2018, conversion of the Caelum Convertible Notes was probable and as such the fair value approximated cost. The Caelum Convertible Notes were converted during 2019. As of January 2019 the following inputs were utilized to derive the notes’ fair value: ​ ​ ​ ​ ​ ​ ​ January ​ 2019 Risk-free interest rate 2.302 % Expected dividend yield — % Expected term in years 0.32 ​ Expected volatility 67 %
Fair Value of Liabilities Measured on Recurring Basis	​ ​ ​ ​ ​ ​ Caelum ​ ​ Convertible ​ ​ Notes, at fair ($ in thousands) ​ value Beginning balance at January 1, 2019 ​ $ 9,914 Change in fair value of convertible notes ​ (9,914) Ending balance at December 31, 2019 ​ $ —

Licenses Acquired (Tables)

Licenses Acquired (Tables)	12 Months Ended
	Dec. 31, 2020
Licenses Acquired
Schedule of Research and Development-Licenses	For the years ended December 31, 2020 and 2019, the Company’s research and development-licenses acquired are comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended ​ ​ ​ December 31, ($ in thousands) 2020 2019 Partner companies: ​ ​ Avenue ​ $ — ​ $ 1,000 Aevitas ​ ​ 62 ​ ​ — Baergic ​ 11 ​ 3,290 Cellvation ​ 1 ​ — Helocyte ​ ​ — ​ ​ 450 Mustang ​ ​ 2,489 ​ ​ 1,350 Oncogenuity ​ ​ 271 ​ ​ — Total ​ $ 2,834 ​ $ 6,090
Schedule of Research and Development for Licenses Acquired	For the years ended December 31, 2020 and 2019 Mustang recorded the following expense in research and development – licenses acquired: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 City of Hope National Medical Center ​ ​ ​ ​ ​ ​ CD123 (MB-102) 3 ​ $ 334 ​ $ 250 IL13Rα2 (MB-101) 3 ​ ​ 334 ​ ​ — HER2 (MB-103) 1 ​ ​ 500 ​ ​ — CS1 (MB-104) ​ ​ 200 ​ ​ 200 PSCA (MB-105) 3 ​ 200 ​ 200 Spacer ​ ​ 334 ​ ​ — Fred Hutch - CD20 (MB-106) 2 ​ ​ 300 ​ ​ — Nationwide Children’s Hospital - C134 (MB-108) ​ ​ — ​ ​ 200 CSL Behring (Calimmune) ​ ​ 170 ​ ​ 200 UCLA ​ ​ — ​ ​ 300 SIRION LentiBOOST TM ​ ​ 117 ​ ​ — Total ​ $ 2,489 ​ $ 1,350

Sponsored Research and Clinic_2

Sponsored Research and Clinical Trial Agreements (Tables)	12 Months Ended
	Dec. 31, 2020
Aevitas [Member]
Schedule of Research and Development for Sponsored Research and Clinical Trial Agreements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 UMass - adeno-associated virus ("AAV") ​ $ 381 ​ $ — UPenn - AAV ​ ​ 567 ​ ​ 1,067 Duke - AAV ​ ​ — ​ ​ 66 Total ​ $ 948 ​ $ 1,133
Mustang [Member]
Schedule of Research and Development for Sponsored Research and Clinical Trial Agreements	For the years ended December 31, 2020 and 2019 Mustang recorded the following expense in research and development for sponsored research and clinical trial agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 City of Hope National Medical Center ​ $ 500 ​ $ 2,000 CD123 (MB-102) ​ 433 ​ 1,202 IL13Rα2 (MB-101) ​ 530 ​ 876 Manufacturing ​ — ​ 457 CS1 (MB-104) ​ ​ 885 ​ ​ — HER2 (MB-103) ​ ​ 1,519 ​ ​ — PSCA (MB-105) ​ ​ 204 ​ ​ — Beth Israel Deaconess Medical Center - CRISPR ​ ​ — ​ ​ 69 St. Jude Children's Research Hospital - XSCID (MB-107) ​ ​ 1,842 ​ ​ 777 Fred Hutchinson Cancer Research Center - CD20 (MB-106) ​ ​ 1,804 ​ ​ 762 Total ​ $ 7,717 ​ $ 6,143

Intangibles, net (Tables)

Intangibles, net (Tables)	12 Months Ended
	Dec. 31, 2020
Intangibles, net
Schedule of JMC Intangible Asset	The table below provides a summary of intangible assets as of December 31, 2020 and 2019, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated Useful ​ ​ ​ ​ ($ in thousands) Lives (Years) December 31, 2020 December 31, 2019 Total Intangible assets – asset purchases ​ 3 to 7 ​ $ 18,606 ​ $ 9,934 Accumulated amortization ​ (3,977) ​ (2,557) Net intangible assets ​ $ 14,629 ​ $ 7,377
Schedule of JMC recognized expense related to its product licenses	The table below provides a summary for the years ended December 31, 2020 and 2019, of recognized expense related to product licenses, which was recorded in costs of goods sold on the Consolidated Statement of Operations (see Note 19): ​ ​ ​ ​ ​ ​ ​ Intangible ($ in thousands) Assets, Net Beginning balance at December 31, 2018 ​ $ 1,417 Additions: ​ ​ ​ Purchase of Ximino 1 ​ ​ 7,134 Amortization expense ​ ​ (1,174) Beginning balance at December 31, 2019 ​ ​ 7,377 Additions: ​ ​ ​ Isotretinoin Agreement 2 ​ ​ 4,727 Anti-itch product license acquisition 3 ​ ​ 3,945 Amortization expense ​ (1,420) Ending balance at December 31, 2020 ​ $ 14,629 ​ Note 1: Includes an upfront payment of $2.4 million and four payments totaling $7.0 million due in consecutive years commencing on the second anniversary of the execution of the APA. Such payments were discounted by $2.3 million as a result of the long-term nature of such payments. Note 2: Includes an upfront payment of $1.0 million and a milestone payment of $0.5 million in 2020 and three payments totaling $3.5 million due at various points between 2021 through 2023. Such payments were discounted by $0.3 million as a result of the long-term nature of such payments. As of December 31, 2020, this asset has not yet been placed in service, therefore no amortization expense was recognized on this asset for the year ended December 31, 2020. Journey expects the asset to be placed in service in the first half of 2021. Once the asset is placed in service Journey will amortize the asset over five years, which represents its expected useful life. Note 3: Includes an upfront payment of $0.2 million and three payments totaling $2.8 million in 2021 and $1.0 million in 2022. Such payments were discounted by $0.1 million as a result of the long-term nature of such payments. As of December 31, 2020, this asset has not yet been placed in service, therefore no amortization expense was recognized on this asset for the year ended December 31, 2020. The Company expects to launch this asset in Q3 2021. Once the asset is placed in service Journey will amortize the asset over three years, which represents its expected useful life.
Schedule of future amortization of intangible assets	The future amortization of these intangible assets is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total ($ in thousands) Ximino® Exelderm® Amortization Year Ended December 31, 2021 ​ $ 1,019 ​ $ 267 ​ $ 1,286 Year Ended December 31, 2022 ​ 1,019 ​ — ​ 1,019 Year Ended December 31, 2023 ​ ​ 1,019 ​ ​ — ​ ​ 1,019 Year Ended December 31, 2024 ​ ​ 1,019 ​ ​ — ​ ​ 1,019 Year Ended December 31, 2025 ​ 1,019 ​ — ​ 1,019 Thereafter ​ ​ 595 ​ ​ — ​ ​ 595 Sub-total ​ ​ 5,690 ​ ​ 267 ​ ​ 5,957 Intangible assets not yet placed in service ​ ​ — ​ ​ — ​ ​ 8,672 Total ​ $ 5,690 ​ $ 267 ​ $ 14,629

Debt and Interest (Tables)

Debt and Interest (Tables)	12 Months Ended
	Dec. 31, 2020
Debt and Interest
Schedule of Debt	Total debt consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ($ in thousands) ​ 2020 ​ 2019 ​ Interest rate ​ Maturity IDB Note ​ $ — ​ $ 14,929 2.25 % Aug - 2021 2017 Subordinated Note Financing 3 ​ — ​ 3,254 8.00 % March - 2022 2017 Subordinated Note Financing 3 ​ — ​ 13,893 8.00 % May - 2022 2017 Subordinated Note Financing 3 ​ — ​ 1,820 8.00 % June - 2022 2017 Subordinated Note Financing 3 ​ — ​ 3,018 8.00 % August - 2022 2017 Subordinated Note Financing 3 ​ — ​ 6,371 8.00 % September - 2022 2018 Venture Notes 4 ​ — ​ 6,517 8.00 % August - 2021 2018 Venture Notes 4 ​ — ​ 15,190 8.00 % September - 2021 2019 Notes 1 ​ — ​ 9,000 12.00 % September - 2021 Mustang Horizon Notes 2 ​ — ​ 15,750 9.00 % October - 2022 Oaktree Note ​ ​ 60,000 ​ ​ — ​ 11.00 % August - 2025 Total notes payable ​ 60,000 ​ 89,742 Less: Discount on notes payable ​ 8,323 ​ 5,086 Total notes payable ​ $ 51,677 ​ $ 84,656 ​ Note 1: Formerly the Opus Credit Facility (see Note 17). Note 2: Interest rate is 9.0% plus one-month LIBOR Rate in excess of 2.5%; at December 31, 2019, $1.2 million is included in Notes payable, short-term on the Consolidated Balance Sheet. Note 3: As a result of a one year maturity date extension, the interest rate of 9.0% takes effect in year 4 of the note. Note 4: At December 31, 2019, $6.0 million is included in Notes payable, short-term on the Consolidated Balance Sheet.
Interest Expense for all Debt Arrangements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 ​ 2019 ($ in thousands) Interest Fees Total Interest Fees Total IDB Note ​ $ 246 ​ $ — ​ $ 246 ​ $ 356 ​ $ - ​ $ 356 2017 Subordinated Note Financing 1 ​ 2,870 ​ 1,890 ​ 4,760 ​ 4,220 ​ 1,381 ​ 5,601 2019 Notes ​ 710 ​ — ​ 710 ​ 1,113 ​ ​ 336 ​ 1,449 2018 Venture Notes 1 ​ 1,253 ​ 1,000 ​ 2,253 ​ 1,737 ​ 639 ​ 2,376 LOC Fees ​ 34 ​ — ​ 34 ​ 60 ​ — ​ 60 Mustang Horizon Notes 1,3 ​ 1,585 ​ 2,321 ​ 3,906 ​ 1,042 ​ 710 ​ 1,752 Oaktree Note 1 ​ ​ 2,311 ​ ​ 411 ​ ​ 2,722 ​ ​ — ​ ​ — ​ ​ — Note Payable 2 ​ ​ 697 ​ ​ — ​ ​ 697 ​ ​ — ​ ​ 255 ​ ​ 255 Other ​ (2) ​ — ​ (2) ​ — ​ ​ — ​ ​ — Total Interest Expense and Financing Fee ​ $ 9,704 ​ $ 5,622 ​ $ 15,326 ​ $ 8,528 ​ $ 3,321 ​ $ 11,849 ​ Note 1:For the year ended December 31, 2020, includes $1.2 million expense of unamortized debt discount fees for the 2017 Subordinated Note Financing, $0.3 million for the 2018 Venture Notes and $1.8 million for the Mustang Horizon Notes. Note 2: Imputed interest expense related to Ximino purchase (see Note 9). Note 3: Includes $0.6 million of prepayment penalties included in interest expense for the Mustang Horizon Notes.

Accrued Liabilities and other_2

Accrued Liabilities and other Long-Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2020
Accrued Liabilities and other Long-Term Liabilities
Schedule of Accrued Expenses and Other Long-Term Liabilities	Accrued expenses and other long-term liabilities consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ($ in thousands) 2020 2019 Accrued expenses: ​ ​ Professional fees ​ $ 1,236 ​ $ 1,153 Salaries, bonus and related benefits ​ 6,701 ​ 6,683 Research and development ​ 5,007 ​ 4,215 Research and development - manufacturing ​ 518 ​ 1,017 Research and development - license maintenance fees ​ 461 ​ 361 Research and development - milestones ​ 600 ​ — Accrued royalties payable ​ 2,682 ​ 2,320 Accrued coupon funding expense ​ 10,869 ​ 8,391 Other ​ 1,188 ​ 1,259 Total accrued expenses ​ $ 29,262 ​ $ 25,399 ​ ​ ​ ​ ​ ​ ​ Other long-term liabilities: ​ ​ Deferred rent and long-term lease abandonment charge 1 ​ $ 1,949 ​ $ 2,136 Partner company note payable, long-term ​ ​ ​ ​ ​ ​ Ximino agreement 2 ​ ​ 3,622 ​ ​ 4,990 Isotretinoin agreement 3 ​ ​ 2,792 ​ ​ — Anti-itch product agreement 4 ​ ​ 945 ​ ​ — Total other long-term liabilities and partner company note payable, long-term ​ $ 9,308 ​ $ 7,126 ​ Note 1: Balance consists of deferred charges related to build-out of the New York facility Note 2: As of December 31, 2019, Journey recorded a note payable, net of an imputed interest discount of $2.3 million, of $4.7 million in connection with its acquisition of Ximino, see Note 9. The imputed interest discount was calculating utilizing an 11.96% effective interest rate based upon a non-investment grade “CCC” rate over a five-year period. Amortization of interest discount was $0.6 million and $0.3 million for the years ended December 31, 2020 and 2019, respectively. At December 31, 2020, $2.0 million was classified as Partner company note payable, short-term on the Company’s Consolidated Balance Sheet. Note 3: As of December 31, 2020, Journey recorded a note payable, net of an imputed interest discount of $0.3 million, of $3.7 million in connection with its acquisition of the Isotretinoin agreement, see Note 9. The imputed interest discount was calculated utilizing a 4.00% effective rate, which represents the market rate for an asset-backed three year loan, secured by receivables. Amortization of interest discount was $0.1 million for the year ended December 31, 2020. At December 31, 2020, $0.5 million of note payable was classified as Partner company note payable, short-term on the Company’s Consolidated Balance Sheet. Note 4: As of December 31, 2020, Journey recorded a note payable, net of an imputed interest discount of $0.1 million, of $3.7 million in connection with its acquisition of an anti-itch product, see Note 9. The imputed interest discount was calculated utilizing a 4.25% effective rate, which represents the market rate for an asset-backed three year loan, secured by receivables. Amortization of interest discount was negligible for the year ended December 31, 2020. As of December 31, 2020, $2.8 million of note payable was classified as Partner company note payable, short-term on the Company’s Consolidated Balance Sheet.

Non-Controlling Interests (Tabl

Non-Controlling Interests (Tables)	12 Months Ended
	Dec. 31, 2020
Non-Controlling Interests
Schedule of Non-Controlling Interests in Consolidated Entities	Non-controlling interests in consolidated entities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ ​ ​ As of December 31, 2020 ​ December 31, 2020 ​ As of December 31, 2020 ​ ​ ​ ​ ​ ​ ​ Net loss attributable to ​ Non-controlling interests ​ Non-controlling ($ in thousands) NCI equity share ​ non-controlling interests ​ in consolidated entities ​ ownership Acquisition Corp VIII ​ $ (7) ​ $ (27) ​ $ (34) 10.0 % Aevitas ​ ​ (2,370) ​ (823) ​ (3,193) 39.0 % Avenue 2 ​ 5,800 ​ (3,974) ​ 1,826 77.4 % Baergic ​ (1,662) ​ (97) ​ (1,759) 39.5 % Cellvation ​ (1,089) ​ (182) ​ (1,271) 22.1 % Checkpoint 1 ​ 41,704 ​ (13,265) ​ 28,439 80.4 % Coronado SO ​ (290) ​ — ​ (290) 13.0 % Cyprium ​ 567 ​ (1,478) ​ (911) 30.5 % Helocyte ​ (4,986) ​ (259) ​ (5,245) 18.8 % JMC ​ 138 ​ 491 ​ 629 7.1 % Mustang 2 ​ 116,060 ​ (36,429) ​ 79,631 80.9 % Oncogenuity ​ ​ (82) ​ (376) ​ (458) 25.3 % Tamid ​ (663) ​ (40) ​ (703) 22.8 % Total ​ $ 153,120 ​ $ (56,459) ​ $ 96,661 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended ​ ​ ​ ​ ​ As of December 31, 2019 ​ December 31, 2019 ​ As of December 31, 2019 ​ ​ ​ ​ ​ ​ ​ Net loss attributable to ​ Non-controlling interests ​ Non-controlling ($ in thousands) NCI equity share non-controlling interests in consolidated entities ownership Aevitas ​ $ (1,249) ​ $ (694) ​ $ (1,943) 35.8 % Avenue 2 ​ 24,269 ​ (19,011) ​ 5,258 77.3 % Baergic ​ 23 ​ (1,162) ​ (1,139) 33.0 % Cellvation ​ (732) ​ (158) ​ (890) 20.6 % Checkpoint 1 ​ 29,389 ​ (14,687) ​ 14,702 78.0 % Coronado SO ​ (290) ​ — ​ (290) 13.0 % Cyprium ​ (320) ​ (99) ​ (419) 10.6 % Helocyte ​ (4,322) ​ (402) ​ (4,724) 19.3 % JMC ​ (211) ​ 325 ​ 114 6.9 % Mustang 2 ​ 62,025 ​ (25,727) ​ 36,298 70.3 % Tamid ​ (565) ​ (85) ​ (650) 22.8 % Total ​ $ 108,017 ​ $ (61,700) ​ $ 46,317 ​ ​ ​ Note 1: Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights. Note 2: Avenue and Mustang are consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Preferred Class A Shares which provide super-majority voting rights.

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	12 Months Ended
	Dec. 31, 2020
Net Loss per Common Share
Schedule of Diluted Weighted Average Shares Outstanding	The following shares of potentially dilutive securities, weighted during the years ended December 31, 2020 and 2019 have been excluded from the computations of diluted weighted average shares outstanding as the effect of including such securities would be antidilutive: ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2020 2019 Warrants to purchase Common Stock 3,419,812 2,729,186 Options to purchase Common Stock 1,103,643 1,179,680 Convertible preferred stock — 1,038,251 Unvested Restricted Stock 14,302,004 12,625,144 Unvested Restricted Stock Units 391,336 721,478 Total 19,216,795 18,293,739

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity
Stock Based Compensation Plans of Partner Companies	Certain partner companies have their own equity compensation plan under which shares are granted to eligible employees, directors and consultants in the form of restricted stock, stock options, and other types of grants of stock of the respective partner company’s common stock. The table below provides a summary of those plans as of December 31, 2020: ​ ​ ​ ​ ​ ​ ​ ​ Partner ​ ​ ​ Shares ​ Shares available at Company Stock Plan Authorized December 31, 2020 Aevitas ​ Aevitas Therapeutics, Inc. 2018 Long Term Incentive Plan ​ 2,000,000 ​ 1,602,000 Avenue Avenue Therapeutics, Inc. 2015 Stock Plan 2,000,000 229,436 Baergic FBIO Acquisition Corp. III 2017 Incentive Plan 2,000,000 1,150,000 Cellvation Cellvation Inc. 2016 Incentive Plan 2,000,000 300,000 Checkpoint Checkpoint Therapeutics, Inc. Amended and Restated 2015 Stock Plan 9,000,000 4,288,465 Cyprium Cyprium Therapeutics, Inc. 2017 Stock Plan 2,000,000 575,000 Helocyte DiaVax Biosciences, Inc. 2015 Incentive Plan 2,000,000 341,667 Journey Journey Medical Corporation 2015 Stock Plan 3,642,857 34,000 Mustang Mustang Bio, Inc. 2016 Incentive Plan 5,000,000 1,180,085 Oncogenuity, Inc. ​ FBIO Acquisition Corp. VII 2017 Incentive Plan ​ 2,000,000 ​ 1,600,000 Tamid FBIO Acquisition Corp. V 2017 Incentive Plan 2,000,000 1,600,000
Schedule of Stock-Based Compensation Expense	The following table summarizes the stock-based compensation expense from stock option, employee stock purchase programs and restricted Common Stock awards and warrants for the years ended December 31, 2020 and 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ($ in thousands) 2020 2019 Employee awards ​ $ 4,991 ​ $ 3,666 Executive awards of Fortress Companies' stock ​ 1,504 ​ 1,428 Non-employee awards ​ 159 ​ 121 Warrants ​ ​ 130 ​ ​ 97 Partner Companies: ​ ​ ​ ​ ​ ​ Avenue ​ 710 ​ 1,839 Checkpoint ​ 2,780 ​ 3,121 Mustang ​ 2,987 ​ 2,664 Other ​ 190 ​ 252 Total stock-based compensation expense ​ $ 13,451 ​ $ 13,188
Schedule of Stock Option Activities	The following table summarizes Fortress stock option activities excluding activities related to partner companies: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average ​ ​ ​ ​ ​ ​ ​ Total ​ remaining ​ ​ ​ ​ Weighted average ​ weighted average ​ contractual life ​ Shares exercise price intrinsic value (years) Options vested and expected to vest at December 31, 2018 ​ 1,285,501 ​ $ 3.75 ​ $ — ​ 2.93 Granted ​ 125,000 ​ ​ 1.18 ​ ​ 173,750 ​ ​ Options vested and expected to vest at December 31, 2019 1,410,501 ​ $ 4.30 ​ $ 684,752 2.33 Exercised (100,000) ​ ​ 1.18 ​ — — Forfeited ​ (257,011) ​ ​ 2.57 ​ ​ — ​ — Options vested and expected to vest at December 31, 2020 1,053,490 ​ $ 5.02 ​ $ 647,482 2.63
Schedule of Restricted Stock Awards and Restricted Stock Units	The following table summarizes Fortress restricted stock awards and restricted stock units activities, excluding activities related to Fortress subsidiaries: ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ average grant ​ ​ Number of shares ​ price Unvested balance at December 31, 2018 12,645,982 ​ $ 2.72 Restricted stock granted 1,546,408 ​ 0.88 Restricted stock vested (220,000) ​ 3.16 Restricted stock units granted ​ 290,000 ​ ​ 1.49 Restricted stock units forfeited (135,416) ​ 3.91 Restricted stock units vested (358,960) ​ 3.61 Unvested balance at December 31, 2019 ​ 13,768,014 ​ $ 2.46 Restricted stock granted ​ 1,873,072 ​ ​ 2.57 Restricted stock vested ​ (230,000) ​ ​ 2.78 Restricted stock units granted ​ 630,126 ​ ​ 3.82 Restricted stock units forfeited ​ (148,750) ​ ​ 3.30 Restricted stock units vested ​ (384,958) ​ ​ 3.49 Unvested balance at December 31, 2020 ​ 15,507,504 ​ $ 2.49
Schedule of Warrant activities	The following table summarizes Fortress warrant activities, excluding activities related to partner companies: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total weighted ​ Weighted average ​ ​ ​ ​ ​ ​ ​ average ​ remaining ​ ​ Number of ​ Weighted average ​ intrinsic ​ contractual life ​ shares exercise price value (years) Outstanding as of December 31, 2018 2,754,189 ​ $ 3.28 ​ $ — ​ 3.49 Granted ​ 60,000 ​ ​ 1.92 ​ ​ 39,000 ​ — Forfeited ​ (73,009) ​ 5.65 ​ — ​ — Outstanding as of December 31, 2019 2,741,180 ​ $ 3.19 ​ $ 111,000 2.73 Granted 1,849,450 ​ 3.14 ​ 101,000 — Forfeited (9) ​ 3.00 ​ 2 — Outstanding as of December 31, 2020 4,590,621 ​ $ 3.17 ​ $ 607,848 4.85 Exercisable as of December 31, 2020 4,430,621 ​ $ 3.21 ​ $ 452,848 4.80

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies
Schedule of lease expense	During the years ended December 31, 2020 and 2019, the Company recorded $3.2 million and $3.2 million, respectively, as lease expense to current period operations. ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ($ in thousands) ​ 2020 ​ 2019 Lease Cost ​ ​ ​ ​ ​ Operating lease cost ​ $ 3,246 ​ $ 3,199 Shared lease costs ​ (1,873) ​ ​ (1,876) Variable lease cost ​ 593 ​ ​ 801 Total lease expense ​ $ 1,966 ​ $ 2,124
Summary of Quantitative Information about Operating Leases	The following tables summarize quantitative information about the Company’s operating leases, under the adoption of ASC Topic 842 , Leases ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ($ in thousands) ​ 2020 ​ 2019 Operating cash flows from operating leases ​ $ (2,958) ​ $ (3,001) ​ Right-of-use assets exchanged for new operating lease liabilities ​ ​ 634 ​ ​ — ​ Weighted-average remaining lease term – operating leases (years) ​ 5.7 ​ 6.3 ​ Weighted-average discount rate – operating leases ​ 6.3 % 6.2 %
Schedule of Future Minimum Lease Payments	​ ​ ​ ​ ​ ​ Future Lease ($ in thousands) ​ Liability Year Ended December 31, 2021 ​ $ 3,353 Year Ended December 31, 2022 ​ 3,461 Year Ended December 31, 2023 ​ 3,233 Year Ended December 31, 2024 ​ 3,193 Year Ended December 31, 2025 ​ 3,244 Other ​ 17,028 Total operating lease liabilities ​ 33,512 Less: present value discount ​ (8,772) Net operating lease liabilities, short-term and long-term ​ $ 24,740

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Related Party Transactions
Schedule of effective date and PIK dividend or equity fee payable	The following table summarizes, by subsidiary, the effective date of the Founders Agreements and PIK dividend or equity fee payable to the Company in accordance with the terms of the Founders Agreements, Exchange Agreements and the partner companies’ certificates of incorporation. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PIK Dividend as ​ ​ ​ ​ ​ ​ a % of fully ​ ​ ​ ​ ​ ​ diluted ​ ​ ​ ​ ​ ​ outstanding ​ Class of Stock Fortress Partner Company Effective Date 1 capitalization Issued Helocyte ​ March 20, 2015 2.5 % Common Stock Avenue ​ February 17, 2015 0.0 % 2 Common Stock Mustang ​ March 13, 2015 2.5 % Common Stock Checkpoint ​ March 17, 2015 0.0 % 3 Common Stock Cellvation ​ October 31, 2016 2.5 % Common Stock Caelum ​ January 1, 2017 0.0 % 4 Common Stock Baergic ​ December 17, 2019 5 ​ 2.5 % Common Stock Cyprium ​ March 13, 2017 2.5 % Common Stock Aevitas ​ July 28, 2017 2.5 % Common Stock Oncogenuity ​ April 22, 2020 5 ​ 2.5 % Common Stock ​ Note 1: Represents the effective date of each subsidiary’s Founders Agreement. Each PIK dividend and equity fee is payable on the annual anniversary of the effective date of the original Founders Agreement or has since been amended to January 1 of each calendar year. Note 2: Pursuant to the terms of the agreement between Avenue and InvaGen Pharmaceuticals, Inc. during the term of the Avenue SPMA PIK dividends will not be paid or accrued. Note 3: Instead of a PIK dividend, Checkpoint pays the Company an annual equity fee in shares of Checkpoint’s common stock equal to 2.5% of Checkpoint’s fully diluted outstanding capitalization. Note 4: Effective January 31, 2019 the Caelum Founders Agreement and MSA with Fortress were terminated in conjunction with the execution of the DOSPA between Caelum and Alexion (See Note 4). Note 5: Represents the Trigger Date, the date that the Fortress partner company first acquires, whether by license or otherwise, ownership rights in a product.
Dividends Declared	The following table summarizes, by subsidiary, the PIK dividend or equity fee recorded by the Company in accordance with the terms of the Founders Agreements, Exchange Agreements and the partner companies’ certificates of incorporation for the years ended December 31, 2020 and 2019 ($ in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ PIK Dividend ​ Year Ended ​ Year Ended Partner company Date December 31, 2020 1 December 31, 2019 Aevitas ​ January 1 ​ $ 11 ​ $ 6 Caelum 2 January 1 ​ — ​ — Cellvation January 1 ​ 7 ​ 7 Checkpoint January 1 ​ 4,617 ​ 2,510 Cyprium January 1 ​ 711 ​ 5 Helocyte January 1 ​ 138 ​ 131 Mustang January 1 ​ 7,577 ​ 4,923 Tamid January 1 ​ — ​ 7 Fortress ​ ​ ​ (13,061) ​ (7,589) Total ​ ​ ​ $ — ​ $ — ​ Note 1: Includes 2021 PIK dividend accrued for the year ended December 31, 2020, as Type 1 subsequent event. Note 2: Pursuant to the terms of the Amended and Restated Mutual Conditional Termination Agreement between Fortress and Caelum, the Founders Agreement dated January 1, 2017 was terminated upon signing of the DOSPA with Alexion on January 30, 2019.
Schedule of effective date and annual consulting fee payable by the subsidiary to the Company	​ The following table summarizes, by partner company, the effective date of the MSA and the annual consulting fee payable by the subsidiary to the Company in quarterly installments ($ in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, Fortress partner company Effective Date 2020 2019 Helocyte ​ March 20, 2015 ​ $ 500 ​ $ 500 Avenue 1 ​ February 17, 2015 ​ — ​ — Mustang ​ March 13, 2015 ​ 500 ​ 500 Checkpoint ​ March 17, 2015 ​ 500 ​ 500 Cellvation ​ October 31, 2016 ​ 500 ​ 500 Baergic ​ March 9, 2017 ​ 500 ​ 500 Cyprium ​ March 13, 2017 ​ 500 ​ 500 Aevitas ​ July 28, 2017 ​ 500 ​ 500 Tamid 2 ​ November 30, 2017 ​ — ​ 500 Oncogenuity 3 ​ February 10, 2017 ​ ​ 500 ​ ​ — Fortress - MSA Income ​ ​ ​ (4,000) ​ (4,000) Consolidated (Income)/Expense ​ ​ ​ $ — ​ $ — ​ Note 1: Pursuant to the terms of the agreement between Avenue and InvaGen Pharmaceuticals, Inc. during the term of the Avenue SPMA fees under the MSA will not be due or accrued. Note 2: In December 2019, Tamid discontinued development and terminated its’ licenses and clinical trial agreements with UNC. Note 3: Oncogenuity license was purchased in the year ended December 31, 2020.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income taxes
Schedule of Components of Income Tax Expense (Benefit)	The components of the income tax provision (benefit) are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ($ in thousands) 2020 2019 Current ​ ​ ​ ​ Federal ​ $ — ​ $ — State ​ 136 ​ — Deferred ​ ​ Federal ​ — ​ — State ​ — ​ — Total ​ $ 136 ​ $ —
Schedule of Deferred Tax Assets and Liabilities	The significant components of the Company’s deferred taxes consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ($ in thousands) ​ 2020 ​ 2019 Deferred tax assets: ​ ​ Net operating loss carryforwards ​ $ 152,295 ​ $ 125,657 Amortization of license fees ​ 20,628 ​ 17,077 Amortization of in-process R&D ​ 415 ​ 449 Stock compensation ​ 14,732 ​ 13,280 Lease liability ​ 7,306 ​ 7,454 Accruals and reserves ​ 1,570 ​ 1,810 Tax credits ​ 16,326 ​ 12,716 Startup costs ​ 54 ​ 58 Unrealized gain/loss on investments ​ 1,075 ​ 716 State taxes ​ 41 ​ — Reserve on Sales Return, Discount and Bad Debt ​ ​ 1,455 ​ ​ — Total deferred tax assets ​ 215,897 ​ 179,217 Less: valuation allowance ​ (203,930) ​ (168,223) Net deferred tax assets ​ $ 11,967 ​ $ 10,994 ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities: ​ ​ Right of use asset ​ $ (6,050) ​ $ (6,280) Fair Value adjustment on investment in Caelum ​ (4,804) ​ ​ (2,879) Basis in subsidiary ​ (1,113) ​ (1,835) Total deferred tax assets, net ​ $ — ​ $ —
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of the statutory tax rates and the effective tax rates is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Year Ended December 31, ​ 2020 2019 Percentage of pre-tax income: ​ ​ ​ U.S. federal statutory income tax rate 21 % 21 % State taxes, net of federal benefit 11 % 12 % Credits 4 % 3 % Non-deductible items (1) % — % Provision to return 1 % 1 % Stock based compensation shortfall (1) % (1) % Change in state rate — % 3 % Deconsolidation of Caelum — % (3) % Change in valuation allowance (35) % (36) % Change in subsidiary basis 1 % (1) % Other (1) % 1 % Effective income tax rate — % — %

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Information
Schedule of Segment Information	The Company operates in two reportable segments, Dermatology Product Sales and Pharmaceutical and Biotechnology Product Development. The accounting policies of the Company’s segments are the same as those described in Note 2. The following tables summarize, for the periods indicated, operating results from continued operations by reportable segment: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmaceutical ​ ​ ​ ​ ​ ​ ​ and ​ ​ ​ ​ ​ Dermatology ​ Biotechnology ​ ​ ​ ($ in thousands) ​ Products ​ Product ​ ​ ​ Year Ended December 31, 2020 Sales Development Consolidated Net revenue ​ $ 44,531 ​ $ 1,068 ​ $ 45,599 Direct cost of goods ​ (14,594) ​ — ​ (14,594) Sales and marketing costs ​ (17,384) ​ — ​ (17,384) Research and development ​ — ​ (64,109) ​ (64,109) General and administrative ​ ​ (4,716) ​ ​ (39,066) ​ ​ (43,782) Other expense ​ (697) ​ (7,882) ​ (8,579) Income tax expense ​ ​ (96) ​ ​ (40) ​ ​ (136) Segment income (loss) ​ $ 7,044 ​ $ (110,029) ​ $ (102,985) Segment assets ​ ​ ​ ​ ​ ​ ​ ​ ​ Intangible assets, net ​ ​ 14,629 ​ ​ — ​ ​ 14,629 Tangible assets ​ ​ 30,843 ​ ​ 283,362 ​ ​ 314,205 Total segment assets ​ $ 45,472 ​ $ 283,362 ​ $ 328,834 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmaceutical ​ ​ ​ ​ ​ ​ ​ ​ and ​ ​ ​ ​ ​ Dermatology ​ Biotechnology ​ ​ ​ ($ in thousands) ​ Products ​ Product ​ ​ ​ Year Ended December 31, 2019 Sales Development Consolidated Net revenue ​ $ 34,921 ​ $ 1,708 ​ $ 36,629 Direct cost of goods ​ (10,532) ​ — ​ (10,532) Sales and marketing costs ​ (17,120) ​ — ​ (17,120) Research and development ​ — ​ (81,326) ​ (81,326) General and administrative ​ (2,556) ​ (35,914) ​ (38,470) Other income ​ — ​ 9,159 ​ 9,159 Segment income (loss) ​ $ 4,713 ​ $ (106,373) ​ $ (101,660) Segment assets ​ ​ ​ ​ ​ ​ ​ ​ ​ Intangible assets, net ​ 7,377 ​ ​ — ​ ​ 7,377 Tangible assets ​ 19,946 ​ ​ 199,099 ​ ​ 219,045 Total segment assets ​ $ 27,323 ​ $ 199,099 ​ $ 226,422

Revenues from Contracts and S_2

Revenues from Contracts and Significant Customers (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of total revenues	The table below summarizes the Company’s revenue for the years ended December 31, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ($ in thousands) 2020 2019 Revenue ​ ​ ​ ​ ​ ​ ​ Product revenue, net ​ $ 44,531 ​ $ 34,921 ​ Revenue – related party ​ 1,068 ​ 1,708 ​ Net revenue ​ $ 45,599 ​ $ 36,629 ​

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2020USD ($)	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)
Accounting Policies [Line Items]
Number of operating segment | segment		2
Number of reportable segment | segment		2
Restricted cash			$ 16,600
Allowance for doubtful accounts		$ 100	100
Proceeds from issuance of preferred stock		39,075	6,038
Long-lived assets, impairment charges		0	0
Revenue from Contract with Customer, Including Assessed Tax		44,531	34,921
Allowance for sales returns		4,600	5,400
Expenses related to sales returns		1,300	2,900
Bad debt expense		49	100
Operating lease liabilities		24,740	24,700
Operating leases, right of use assets		20,487	21,480
Retained earnings (accumulated deficit)		(482,760)	(436,234)
Notes Payable [Member]
Accounting Policies [Line Items]
Restricted cash			15,000
Letter of Credit [Member]
Accounting Policies [Line Items]
Restricted cash		1,600	$ 1,600
Opus Credit Facility (2019 Notes) [Member]
Accounting Policies [Line Items]
Weighted average effective interest rate			16.00%
Repayments of debt	$ 21,700	9,000
Held-to-maturity Securities [Member]
Accounting Policies [Line Items]
Short-term investments		0	$ 0
Cash and Cash Equivalents [Member]
Accounting Policies [Line Items]
Short-term investments		$ 76,800	15,000
Oaktree Note [Member]
Accounting Policies [Line Items]
Weighted average effective interest rate		15.13%
Accounting Standards Update 2016-02 [Member]
Accounting Policies [Line Items]
Operating lease liabilities				$ 26,800
Operating leases, right of use assets				23,000
Deferred rent credit				3,800
Retained earnings (accumulated deficit)				$ 0
Mustang [Member]
Accounting Policies [Line Items]
Costs for the design and construction of the facility		$ 500	$ 1,200
Cyprium [Member]
Accounting Policies [Line Items]
Proceeds from issuance of preferred stock		$ 8,000

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies
Cash and cash equivalents	$ 233,351	$ 136,858
Restricted cash	1,645	16,574
Total cash and cash equivalents and restricted cash	$ 234,996	$ 153,432	$ 81,582

Discontinued Operations (Narrat

Discontinued Operations (Narrative) (Details) - USD ($) $ in Thousands, shares in Millions	Feb. 11, 2019	Nov. 14, 2018	Dec. 31, 2019
Proceeds from sale of National			$ 13,089
Discontinued Operations [Member] | National Holdings Corporation "NHC" [Member]
Sale of National, total consideration		$ 22,900
Sale of National, number of shares sold	4	3
Proceeds from sale of National	$ 13,100	$ 9,800
Ownership percentage			0.00%

Discontinued Operations (Schedu

Discontinued Operations (Schedule of Cash Flows Statement) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Investing activities
Proceeds from sale of National		$ 13,089
Total cash provided by discontinued investing activities	$ 0	$ 13,089

Collaboration and Stock Purch_3

Collaboration and Stock Purchase Agreements (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Feb. 08, 2019	Jan. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Caelum [Member]
Business Acquisition, Percentage of Voting Interests Acquired		40.00%
Caelum [Member] | Alexion [Member]
Percentage of shares transferred on a share transaction		19.90%
Sale of Stock, Consideration Received on Transaction		$ 30
Initial contingent payments				$ 30
Additional upfront funding				20
Funding for additional equity interest				$ 60
Potential Additional Payments, Maximum		$ 500
Sales [Member] | Caelum [Member] | InvaGen [Member]
Net sales threshold			$ 325
Sales After January 1. 2029 [Member] | Caelum [Member] | InvaGen [Member]
Gross Profit Percentage To Net Sales			20.00%
Contingent Earn Out Payments Measurement Second Model			$ 1,500
Slab One [Member] | Caelum [Member] | InvaGen [Member]
Gross Profit Percentage To Net Sales			10.00%
Slab One [Member] | Sales [Member] | Caelum [Member] | InvaGen [Member]
Net sales threshold			$ 400
Slab One [Member] | Sales After January 1. 2029 [Member] | Caelum [Member] | InvaGen [Member]
Net sales threshold			$ 100
Slab Two [Member] | Caelum [Member] | InvaGen [Member]
Gross Profit Percentage To Net Sales			12.50%
Slab Two [Member] | Sales [Member] | Minimum [Member] | Caelum [Member] | InvaGen [Member]
Net sales threshold			$ 400
Slab Two [Member] | Sales [Member] | Maximum [Member] | Caelum [Member] | InvaGen [Member]
Net sales threshold			$ 500
Slab Three [Member] | Caelum [Member] | InvaGen [Member]
Gross Profit Percentage To Net Sales			15.00%
Slab Three [Member] | Sales [Member] | Caelum [Member] | InvaGen [Member]
Net sales threshold			$ 500
SPMA [Member] | Caelum [Member] | InvaGen [Member]
Business Combination, possible Interim financing	$ 7
Business Combination, possible Interim financing, amount drawn			$ 0
First Stage [Member] | SPMA [Member] | Avenue [Member] | InvaGen [Member]
Sale of Stock, Consideration Received on Transaction	$ 35
Sale of stock, price per share	$ 6
Sale of stock, number of shares issued	5.8
Sale of stock, ownership percentage after the transaction	33.30%

Collaboration and Stock Purch_4

Collaboration and Stock Purchase Agreements (Schedule of Assets and Liabilities of Caelum) (Details) - Caelum [Member] - Alexion [Member] $ in Thousands	Jan. 31, 2019USD ($)
Current assets
Cash and cash equivalents	$ 1,201
Prepaid expenses and other current assets	6
Total current assets	1,207
Current liabilities
Accounts payable and accrued expenses	2,246
Interest payable	198
Interest payable - related party	106
Note payable - related party	929
Note payable	9,914
Warrant liability	991
Total current liabilities	14,384
Net liability impacted by deconsolidation	$ 13,177

Collaboration and Stock Purch_5

Collaboration and Stock Purchase Agreements (Schedule of Gain from Deconsolidation of Caelum) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Collaboration and Stock Purchase Agreements
Deconsolidation, fair value		$ 11,148
Net liabilities deconsolidated		13,177
Non-controlling interest share		4,849
Write off of fees due to Fortress		1,000
Gain on deconsolidation of Caelum	$ 0	$ 18,476

Property and Equipment (Narrati

Property and Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property and Equipment
Depreciation expense	$ 2,280	$ 1,922

Property and Equipment (Schedul

Property and Equipment (Schedule of Property and Equipment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 18,689	$ 16,919
Less: Accumulated depreciation	(6,766)	(4,486)
Property and equipment, net	11,923	12,433
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 663	648
Useful Life (Years)	3 years
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 1,199	1,162
Useful Life (Years)	5 years
Machinery & equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,748	4,594
Useful Life (Years)	5 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 10,580	9,358
Leasehold improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (Years)	15 years
Leasehold improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (Years)	2 years
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 499	$ 1,157

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details)	Dec. 31, 2020USD ($)$ / shares	Dec. 31, 2019USD ($)$ / shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value	$ 17,566,000
Caelum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment owned, fair value	17,600,000	$ 11,100,000
Assets, fair value	$ 17,566,000
Caelum [Member] | Share Price [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, measurement input | $ / shares	2.43	1.54
Caelum [Member] | Risk Free Interest Rate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, measurement input	0.0036	0.016
Caelum [Member] | Expected Volatility [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, measurement input	0.70	0.70
Caelum [Member] | Discount for Lack of Marketability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, measurement input		0.287
Caelum [Member] | Discount for Lack of Marketability [Member] | Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, measurement input	0.210
Caelum [Member] | Discount for Lack of Marketability [Member] | Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment, measurement input	0.310

Fair Value Measurements (Weight

Fair Value Measurements (Weighted average Significant Unobservable Inputs) (Details)	Dec. 31, 2020Y	Dec. 31, 2019Y	Jan. 31, 2019USD ($)Y
Caelum [Member] | Warrants [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | $			0.02909
Caelum [Member] | Warrants [Member] | Risk Free Interest Rate [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | $			0.02905
Caelum [Member] | Warrants [Member] | Expected Dividend Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | $			0
Caelum [Member] | Warrants [Member] | Expected Term in Years [Member] | Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | Y			3.84
Caelum [Member] | Warrants [Member] | Expected Term in Years [Member] | Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | Y			3.96
Caelum [Member] | Warrants [Member] | Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | $			0.70
Caelum [Member] | Convertible Notes [Member] | Risk Free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Convertible notes, measurement input			0.02302
Caelum [Member] | Convertible Notes [Member] | Expected Dividend Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Convertible notes, measurement input			0
Caelum [Member] | Convertible Notes [Member] | Expected Term in Years [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Convertible notes, measurement input | Y			0.32
Caelum [Member] | Convertible Notes [Member] | Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Convertible notes, measurement input			0.67
Cyprium [Member] | Warrants [Member] | Risk Free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	0.0069	0.0192
Cyprium [Member] | Warrants [Member] | Expected Dividend Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	0	0
Cyprium [Member] | Warrants [Member] | Expected Term in Years [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input | Y	10	10
Cyprium [Member] | Warrants [Member] | Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	0.85	0.93
Cyprium [Member] | Warrants [Member] | Probability of Issuance of the Warrant [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warrant liability, measurement input	1	0.05

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value of Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Change in fair value of convertible notes		$ (27)
Reclass partner company's warrants from liability to equity	$ (1,216)
Caelum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, Beginning Balance	0	9,914
Change in fair value of convertible notes		(9,914)
Reclass partner company's warrants from liability to equity	0
Liabilities, Ending Balance		0
Warrants [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, Beginning Balance	27	991
Change in fair value of convertible notes		(27)
Reclass partner company's warrants from liability to equity	(1,216)
Liabilities, Ending Balance	0	27
Warrants [Member] | Caelum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, Beginning Balance	0	991
Change in fair value of derivative liabilities		(991)
Liabilities, Ending Balance		0
Warrants [Member] | Cyprium [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Liabilities, Beginning Balance	27	0
Change in fair value of derivative liabilities	1,189	27
Reclass partner company's warrants from liability to equity	(1,216)
Liabilities, Ending Balance	$ 0	$ 27

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Financial Instruments, Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Assets, fair value	$ 17,566
Caelum [Member]
Assets
Assets, fair value	17,566
Liabilities
Liabilities, fair value			$ 11,148
Warrants [Member]
Liabilities
Liabilities, fair value		$ 27
Convertible Notes [Member] | Caelum [Member]
Liabilities
Liabilities, fair value			11,148
Level 3 [Member]
Assets
Assets, fair value	17,566
Level 3 [Member] | Caelum [Member]
Assets
Assets, fair value	$ 17,566
Liabilities
Liabilities, fair value			11,148
Level 3 [Member] | Warrants [Member]
Liabilities
Liabilities, fair value		$ 27
Level 3 [Member] | Convertible Notes [Member] | Caelum [Member]
Liabilities
Liabilities, fair value			$ 11,148

Fair Value Measurements (Roll F

Fair Value Measurements (Roll Forward of the Changes in Fair Value of Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total, Beginning Balance	$ 11,175	$ 10,905
Payment of convertible note		(9,914)
Disposal of National		(991)
Change in fair value of liabilities	1,189
Change in fair value of investments	6,418	11,148
Reclass partner company's warrants from liability to equity	(1,216)
Change in fair value of convertible notes		27
Total, Ending Balance	17,566	11,175
Warrants [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Beginning Balance	27	991
Payment of convertible note		0
Disposal of National		(991)
Change in fair value of liabilities	1,189
Change in fair value of investments	0	0
Reclass partner company's warrants from liability to equity	(1,216)
Change in fair value of convertible notes		27
Liabilities, Ending Balance	0	27
Origo [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investment, Beginning Balance	11,148	0
Payment of convertible note		0
Disposal of National		0
Change in fair value of investments		11,148
Change in fair value of convertible notes		0
Investment, Ending Balance		11,148
Helocyte [Member] | Convertible Notes [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Beginning Balance	0	9,914
Payment of convertible note		(9,914)
Disposal of National		0
Change in fair value of investments		0
Change in fair value of convertible notes		0
Liabilities, Ending Balance		0
Caelum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Investment, Beginning Balance	11,148
Liabilities, Beginning Balance	0	9,914
Change in fair value of liabilities	0
Change in fair value of investments	6,418
Reclass partner company's warrants from liability to equity	0
Change in fair value of convertible notes		9,914
Investment, Ending Balance	17,566	11,148
Liabilities, Ending Balance		0
Caelum [Member] | Warrants [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Beginning Balance	0	991
Liabilities, Ending Balance		0
Cyprium [Member] | Warrants [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Liabilities, Beginning Balance	27	0
Reclass partner company's warrants from liability to equity	(1,216)
Liabilities, Ending Balance	$ 0	$ 27

Licenses Acquired (Narrative) (

Licenses Acquired (Narrative) (Details)

Dec. 17, 2020USD ($)Milestone

Dec. 17, 2019USD ($)Milestoneagreementshares

Oct. 15, 2015USD ($)

Sep. 30, 2015USD ($)shares

May 11, 2015USD ($)$ / sharesshares

Mar. 31, 2015USD ($)Milestone

Dec. 31, 2019USD ($)$ / sharesinstallment

Jun. 30, 2019USD ($)

Mar. 31, 2017USD ($)

Oct. 31, 2016USD ($)Milestoneshares

May 31, 2016USD ($)

Dec. 31, 2015Milestone

Apr. 30, 2015USD ($)Milestone

Mar. 31, 2015USD ($)

Feb. 28, 2015USD ($)

Dec. 31, 2020USD ($)Milestone

Dec. 31, 2019USD ($)$ / shares

Dec. 31, 2020USD ($)

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

$ 2,834,000

$ 6,090,000

Research and Development Expense

64,109,000

81,326,000

Product revenue, net

44,531,000

34,921,000

Maintenance fees paid

50,000

25,000

Licensing Agreements [Member] | Adimab Llc Collaboration Agreement [Member] | Achievement of Each Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 7,100,000

Licensing Agreements [Member] | Adimab Llc Collaboration Agreement [Member] | Upon Various Filings for Regulatory Approvals [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 4,800,000

Aevitas [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

62,000

0

Aevitas [Member] | Licensing Agreements [Member] | University of Massachusetts [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

100,000

Number of net sales milestones | Milestone

4

Aevitas [Member] | Licensing Agreements [Member] | University of Massachusetts [Member] | Achievement of Each Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 1,000,000

Aevitas [Member] | Licensing Agreements [Member] | University of Massachusetts [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 4,000,000

Avenue [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

0

1,000,000

Avenue [Member] | Licensing Agreements [Member] | IV Tramadol [Member] | Revogenex Ireland Ltd [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 3,000,000

Research and development - licenses acquired

0

1,000,000

Payments of milestones

3,000,000

Baergic [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

11,000

3,290,000

Baergic [Member] | Licensing Agreements [Member] | AstraZeneca [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

9,000

0

Number of license agreement | agreement

2

Baergic [Member] | Licensing Agreements [Member] | Cincinnati Children's Hospital Medical Center [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 200,000

Research and development - licenses acquired

2,000

0

Number of net sales milestones | Milestone

4

Number of development milestones | Milestone

2

Payments of milestones

$ 21,000,000

Common shares issued (in shares) | shares

624,922

Reimbursement of past patent expenses

$ 30,000

Payment of upfront licensing fee

$ 6,500,000

Stock Issued During Period, Shares, New Issues | shares

624,922

Percentage of common shares issued (in percent)

5.00%

Amount of net of debt utilized

$ 100,000

Baergic [Member] | Licensing Agreements [Member] | Cincinnati Children's Hospital Medical Center [Member] | Discount for Lack of Marketability [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Common Shares, measurement input

0.446

0.446

Baergic [Member] | Licensing Agreements [Member] | Cincinnati Children's Hospital Medical Center [Member] | Measurement Input Weighted Average Cost of Capital [ Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Common Shares, measurement input

0.205

0.205

Baergic [Member] | Licensing Agreements [Member] | Cincinnati Children's Hospital Medical Center [Member] | Share Price [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Common Shares, measurement input | $ / shares

0.029

0.029

Baergic [Member] | Licensing Agreements [Member] | Maximum [Member] | AstraZeneca [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Issuance of anti-dilution protection of shares

$ 15,000,000

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Amount of net of debt utilized

$ 100,000

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | Share Price [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Common Shares, measurement input | $ / shares

0.029

0.029

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | AstraZeneca [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 3,000,000

Number of net sales milestones | Milestone

3

Common shares issued (in shares) | shares

2,492,192

Stock Issued During Period, Shares, New Issues | shares

2,492,192

Percentage of common shares issued (in percent)

19.95%

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | AstraZeneca [Member] | Achievement of Each Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 75,000,000

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | AstraZeneca [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

130,000,000

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | AstraZeneca [Member] | Discount for Lack of Marketability [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Common Shares, measurement input

0.446

0.446

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | AstraZeneca [Member] | Measurement Input Weighted Average Cost of Capital [ Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Common Shares, measurement input

0.205

0.205

Baergic [Member] | Licensing Agreements [Member] | AZ License [Member] | Maximum [Member] | AstraZeneca [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Issuance of anti-dilution protection of shares

$ 75,000,000

Cellvation [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

1,000

$ 0

Cellvation [Member] | Licensing Agreements [Member] | Initial TBI License [Member] | University of Texas [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 300,000

Common shares issued (in shares) | shares

500,000

Stock Issued During Period, Shares, New Issues | shares

500,000

Percentage of common shares issued (in percent)

5.00%

Cellvation [Member] | Licensing Agreements [Member] | Initial TBI License [Member] | University of Texas [Member] | Development of Adult Indications [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of development milestones | Milestone

9

Payments of milestones

$ 6,200,000

Cellvation [Member] | Licensing Agreements [Member] | Initial TBI License [Member] | University of Texas [Member] | Development of Pediatric Indications [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of development milestones | Milestone

8

Payments of milestones

$ 6,000,000

Cellvation [Member] | Licensing Agreements [Member] | Initial TBI License [Member] | Minimum [Member] | University of Texas [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Additional Minimum Annual Royalty Payable

50,000

Cellvation [Member] | Licensing Agreements [Member] | Initial TBI License [Member] | Maximum [Member] | University of Texas [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Additional Minimum Annual Royalty Payable

200,000

Cellvation [Member] | Licensing Agreements [Member] | Second TBI License [Member] | University of Texas [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

50,000

Research and development - licenses acquired

$ 1,000

0

Payments of milestones

300,000

Common shares issued, value

500,000

Minimum Annual Royalty Payable

$ 100,000

Checkpoint [Member] | Licensing Agreements [Member] | Dana Farber Cancer Institute [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 1,000,000

Common shares issued, value

$ 600,000

$ 32,500

Common shares issued (in shares) | shares

136,830

500,000

Shares issued, price per share | $ / shares

$ 0.065

Issuance of anti-dilution protection of shares

$ 10,000,000

Stock Issued During Period, Shares, New Issues | shares

136,830

500,000

Annual Maintenance Fee Payable

$ 50,000

Checkpoint [Member] | Licensing Agreements [Member] | Dana Farber Cancer Institute [Member] | Checkpoint [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners

5.00%

Checkpoint [Member] | Licensing Agreements [Member] | Dana Farber Cancer Institute [Member] | Achievement of Each Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Issuance of anti-dilution protection of shares

21,500,000

Checkpoint [Member] | Licensing Agreements [Member] | Dana Farber Cancer Institute [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 60,000,000

Checkpoint [Member] | Licensing Agreements [Member] | NeuPharma, Inc. [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payment of upfront licensing fee

$ 1,000,000

Checkpoint [Member] | Licensing Agreements [Member] | NeuPharma, Inc. [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

40,000,000

Checkpoint [Member] | Licensing Agreements [Member] | NeuPharma, Inc. [Member] | Completion of Clinical Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

40,000,000

Checkpoint [Member] | Licensing Agreements [Member] | NeuPharma, Inc. [Member] | Regulatory Approvals to Commercialize the Products [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 22,500,000

Checkpoint [Member] | Licensing Agreements [Member] | Jubilant Biosys Ltd [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 2,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Jubilant Biosys Ltd [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

89,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Jubilant Biosys Ltd [Member] | Achievement of Certain Preclinical, Clinical Development, and Regulatory Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

89,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Jubilant Biosys Ltd [Member] | Regulatory Approvals to Commercialize the Products [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 59,500,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Percentage of IND enabling costs and patent expenses

50.00%

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Upon Various Filings for Regulatory Approvals [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 87,200,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Completion of Clinical Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

25,500,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Achievement of Five Regulatory Approvals [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

61,700,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Achievement of Three Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

89,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Revenue from collaboration agreement

1,000,000

1,600,000

Additional Annual License fee

$ 1,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | Completion of Clinical Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

8,400,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | Upon the Twelfth Patient Dosed in a Phase 1 Clinical Study [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

925,000

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Jubilant Biosys Ltd [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 1,000,000

Number of development milestones | Milestone

3

Revenue from collaboration agreement

$ 100,000

100,000

$ 0

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Jubilant Biosys Ltd [Member] | Achievement of Five Regulatory Approvals [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number Of Regulatory Milestones | Milestone

5

Checkpoint [Member] | Licensing Agreements [Member] | Collaborative Agreements with TGTX [Member] | Jubilant Biosys Ltd [Member] | Achievement of Three Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of net sales milestones | Milestone

3

Checkpoint [Member] | Licensing Agreements [Member] | Anti-PD-L1 [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

500,000

Checkpoint [Member] | Licensing Agreements [Member] | Anti-PD-L1 [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | Achievement of Certain clinical Development, Regulatory and First Commercial Sale milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

27,600,000

Checkpoint [Member] | Licensing Agreements [Member] | Anti-PD-L1 [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | First Commercial Sales in Specified Territories [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

19,200,000

Checkpoint [Member] | Licensing Agreements [Member] | Anti-GITR Antibody [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 60,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Anti-GITR Antibody [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | Achievement of Certain clinical Development, Regulatory and First Commercial Sale milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

21,500,000

Checkpoint [Member] | Licensing Agreements [Member] | Anti-GITR Antibody [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | Completion of Clinical Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 7,000,000

Checkpoint [Member] | Licensing Agreements [Member] | Anti-GITR Antibody [Member] | Collaborative Agreements with TGTX [Member] | Dana Farber Cancer Institute [Member] | First Commercial Sales in Specified Territories [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

14,500,000

Helocyte [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

0

450,000

Helocyte [Member] | Licensing Agreements [Member] | National Institute of Allergy and Infectious Disease (NIAD) [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 500,000

Research and development - licenses acquired

0

500,000

Minimum Annual Royalty Payable

$ 55,000

Payment Of Upfront Fees, Number Of Installments | installment

3

Helocyte [Member] | Licensing Agreements [Member] | National Institute of Allergy and Infectious Disease (NIAD) [Member] | Achievement of Four Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Additional Minimum Annual Royalty Payable

$ 1,050,000

Helocyte [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member] | Achievement of Four Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of development milestones | Milestone

4

Helocyte [Member] | Licensing Agreements [Member] | City of Hope (COH) [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 45,000

Helocyte [Member] | Licensing Agreements [Member] | Triplex [Member] | City of Hope (COH) [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 200,000

Helocyte [Member] | Licensing Agreements [Member] | Triplex [Member] | City of Hope (COH) [Member] | Achievement of Each Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 7,500,000

Helocyte [Member] | Licensing Agreements [Member] | Triplex [Member] | City of Hope (COH) [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of net sales milestones | Milestone

3

Payments of milestones

$ 26,000,000

Helocyte [Member] | Licensing Agreements [Member] | Triplex [Member] | City of Hope (COH) [Member] | Financial Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of net sales milestones | Milestone

3

Number of development milestones | Milestone

2

Payments of milestones

$ 3,700,000

Helocyte [Member] | Licensing Agreements [Member] | Pentameter [Member] | City of Hope (COH) [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

0

0

Helocyte [Member] | Licensing Agreements [Member] | Pentameter [Member] | City of Hope (COH) [Member] | Achievement of Four Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of development milestones | Milestone

4

Payments of milestones

$ 5,500,000

Helocyte [Member] | Licensing Agreements [Member] | Pentameter [Member] | City of Hope (COH) [Member] | Achievement of Three Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of net sales milestones | Milestone

3

Payments of milestones

$ 26,000,000

Helocyte [Member] | Licensing Agreements [Member] | Pentameter [Member] | City of Hope (COH) [Member] | First Marketing Approval [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Minimum Annual Royalty Payable

$ 750,000

Cyprium [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 100,000

Research and development - licenses acquired

$ 0

$ 0

Cyprium [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member] | Achievement of Certain Sales Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

1,000,000

Cyprium [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member] | Completion of Clinical Development Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

1,700,000

Cyprium [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member] | Redeems a PRV [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 15,000,000

Cyprium [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member] | First PRV Sold [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Sales royalties (as a percent)

20.00%

Cyprium [Member] | Licensing Agreements [Member] | National Institutes of Health ("NIH") [Member] | Second PRV Sold [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Sales royalties (as a percent)

15.00%

Licenses Acquired (Mustang - Na

Licenses Acquired (Mustang - Narrative) (Details) € in Millions, shares in Millions

Aug. 23, 2019USD ($)

Aug. 03, 2019Milestone

Aug. 02, 2018USD ($)Milestone

Jan. 03, 2018USD ($)

Nov. 20, 2017USD ($)Milestone

Jul. 03, 2017USD ($)

May 31, 2017USD ($)Milestone

Apr. 25, 2017USD ($)

Mar. 31, 2017USD ($)Milestone

Mar. 17, 2017USD ($)

Oct. 15, 2015USD ($)

Oct. 31, 2020USD ($)Milestone

Oct. 31, 2020EUR (€)Milestone

Mar. 31, 2017USD ($)

Apr. 30, 2015USD ($)

Mar. 31, 2015USD ($)Milestoneshares

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

$ 2,834,000

$ 6,090,000

Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

2,489,000

1,350,000

City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 2,000,000

Research and development - licenses acquired

334,000

0

Common shares issued (in shares) | shares

1

City of Hope (COH) [Member] | Licensing Agreements [Member] | Financial Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of financial milestones

2

City of Hope (COH) [Member] | Licensing Agreements [Member] | Completion of Clinical Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 14,500,000

Number of development milestones | Milestone

6

Royalty Guarantees, Commitments, Amount

$ 1,000,000

CSL Behring [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

170,000

200,000

University of California [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 200,000

Research and development - licenses acquired

0

300,000

Payments of milestones

300,000

0

University of California [Member] | Licensing Agreements [Member] | Completion of Clinical Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 14,300,000

Nationwide Children's Hospital [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

0

200,000

Fred Hutchinson Cancer Research Center [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

300,000

0

Harvard College [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 300,000

Research and development - licenses acquired

0

0

Annual maintenance fee payable

100,000

50,000

$ 25,000

Harvard College [Member] | Licensing Agreements [Member] | Achievement of Seven Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 16,700,000

Number of development milestones | Milestone

7

SIRION Biotech [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

117,000

0

MB-102 (CD 123 CAR T for AML) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

334,000

250,000

$ 0

Payments of milestones

300,000

MB-102 (CD 123 CAR T for AML) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Achievement of Certain Sales Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

14,500,000

MB-102 (CD 123 CAR T for AML) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Upon the Twelfth Patient Dosed in a Phase 1 Clinical Study [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

300,000

MB-108 (C134 Oncolytic Virus for GBM [Member] | Nationwide Children's Hospital [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

200,000

MB-108 (C134 Oncolytic Virus for GBM [Member] | Nationwide Children's Hospital [Member] | Licensing Agreements [Member] | Achievement of Development and Commercialization Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

152,800,000

MB-104 (CS1 CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 600,000

Research and development - licenses acquired

200,000

200,000

Annual maintenance fee payable

50,000

MB-104 (CS1 CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Achievement of Ten Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 14,900,000

Number of development milestones | Milestone

10

MB-105 (PSCA CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

200,000

200,000

MB-105 (PSCA CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Achievement of Ten Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Number of development milestones | Milestone

10

MB-105 (PSCA CAR T) [Member] | University of California [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

300,000

Research and development - licenses acquired

200,000

0

Annual maintenance fee payable

$ 50,000

MB-105 (PSCA CAR T) [Member] | University of California [Member] | Licensing Agreements [Member] | Achievement of Ten Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

14,900,000

MB-106 (Car T Therapy) [Member] | Fred Hutchinson Cancer Research Center [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

300,000

Annual maintenance fee payable

50,000

MB-106 (Car T Therapy) [Member] | Fred Hutchinson Cancer Research Center [Member] | First Commercial Sales in Specified Territories [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 39,100,000

MB-106 (Car T Therapy) [Member] | Fred Hutchinson Cancer Research Center [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

300,000

0

MB-107 (XSCID) [Member] | CSL Behring [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 200,000

Research and development - licenses acquired

200,000

200,000

MB-107 (XSCID) [Member] | CSL Behring [Member] | Licensing Agreements [Member] | Achievement of Development and Commercialization Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 1,200,000

Number of development milestones | Milestone

3

MB-107 (XSCID) [Member] | St Jude Childrens Research Hospital [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 1,000,000

Research and development - licenses acquired

0

0

Annual maintenance fee payable

100,000

MB-107 (XSCID) [Member] | St Jude Childrens Research Hospital [Member] | Licensing Agreements [Member] | Achievement of Five Development and Commercialization Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 13,500,000

Number of development milestones | Milestone

5

MB-103 (HER2 CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

600,000

Research and development - licenses acquired

500,000

0

Annual maintenance fee payable

50,000

MB-103 (HER2 CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Achievement of Ten Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 14,900,000

Number of development milestones | Milestone

10

MB-103 (HER2 CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Upon the Twelfth Patient Dosed in a Phase 1 Clinical Study [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 500,000

MB-103 (HER2 CAR T) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | First Patient Dosed in a Phase 1 Clinical Study [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

200,000

MB-101 (IL13R2 CAR T for Glioblastoma) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Research and development - licenses acquired

334,000

0

MB-101 (IL13R2 CAR T for Glioblastoma) [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Achievement of Each Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

14,500,000

MB-207 (LentiBOOST) [Member] | SIRION Biotech [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 100,000

€ 0.1

Research and development - licenses acquired

100,000

0

MB-207 (LentiBOOST) [Member] | SIRION Biotech [Member] | Licensing Agreements [Member] | Achievement of Five Development Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 5,600,000

€ 4.7

Number of development milestones | Milestone

5

5

MB-207 (LentiBOOST) [Member] | SIRION Biotech [Member] | Licensing Agreements [Member] | Achievement of Three Commercial Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 4,100,000

€ 3.5

Number of financial milestones | Milestone

3

3

Manufacturing License [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 100,000

Research and development - licenses acquired

0

0

Agreement IV/ICV [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Upfront fees payment

$ 100,000

Research and development - licenses acquired

$ 0

$ 0

Agreement IV/ICV [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Achievement of Each Milestones [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 100,000

Adimab Llc Collaboration Agreement [Member] | Licensing Agreements [Member] | Achievement of Each Milestones [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Payments of milestones

$ 7,100,000

Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Percentage of ownership

80.90%

70.30%

Mustang [Member] | City of Hope (COH) [Member] | Licensing Agreements [Member] | Mustang [Member]

Research and Development Arrangement, Contract to Perform for Others [Line Items]

Percentage of ownership

10.00%

Licenses Acquired (Oncogenuity

Licenses Acquired (Oncogenuity and Tamid - Narrative) (Details)	May 06, 2020USD ($)shares	Dec. 31, 2020USD ($)$ / shares	Dec. 31, 2019USD ($)
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired		$ 2,834,000	$ 6,090,000
Oncogenuity [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired		271,000	0
Licensing Agreements [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Upfront fees payment	$ 300,000
Common shares issued (in shares) | shares	1,000,000
Amount of net of debt utilized		21,000
Research and development - licenses acquired		300,000
Licensing Agreements [Member] | Tamid [Member] | University of North Carolina [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired		$ 0	$ 0
Licensing Agreements [Member] | Discount for Lack of Marketability [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Common Shares, measurement input			0.417
Licensing Agreements [Member] | Measurement Input Weighted Average Cost of Capital [ Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Common Shares, measurement input			0.205
Licensing Agreements [Member] | Share Price [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Common Shares, measurement input | $ / shares		0.021
Licensing Agreements [Member] | Completion of Clinical Development Milestones [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	$ 15,300,000
Licensing Agreements [Member] | Achievement of Certain Sales Milestones [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	15,000,000
Licensing Agreements [Member] | Certain Milestones in Connection with the Initial Indication [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments of milestones	$ 18,000,000
Oncogenuity [Member] | Licensing Agreements [Member] | Oncogenuity [Member] | Columbia University [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of ownership	10.00%

Licenses Acquired (Schedule of

Licenses Acquired (Schedule of Research and Development-Licenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	$ 2,834	$ 6,090
Avenue [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	0	1,000
Aevitas [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	62	0
Baergic [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	11	3,290
Cellvation [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	1	0
Helocyte [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	0	450
Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	2,489	1,350
Oncogenuity [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	$ 271	$ 0

Licenses Acquired (Schedule o_2

Licenses Acquired (Schedule of Research and Development for Licenses Acquired) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	$ 2,834	$ 6,090
Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	2,489	1,350
Licensing Agreements [Member] | Mustang [Member] | Spacer [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	2,489	1,350
Licensing Agreements [Member] | City of Hope (COH) [Member] | Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	334	0
Licensing Agreements [Member] | City of Hope (COH) [Member] | Mustang [Member] | MB-102 (CD 123 CAR T for AML) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	334	250	$ 0
Licensing Agreements [Member] | City of Hope (COH) [Member] | Mustang [Member] | MB-101 (IL13R2 CAR T for Glioblastoma) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	334	0
Licensing Agreements [Member] | City of Hope (COH) [Member] | Mustang [Member] | MB-103 (HER2 CAR T) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	500	0
Licensing Agreements [Member] | City of Hope (COH) [Member] | Mustang [Member] | MB-104 (CS1 CAR T) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	200	200
Licensing Agreements [Member] | City of Hope (COH) [Member] | Mustang [Member] | MB-105 (PSCA CAR T) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	200	200
Licensing Agreements [Member] | Fred Hutchinson Cancer Research Center [Member] | Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	300	0
Licensing Agreements [Member] | Nationwide Children's Hospital [Member] | Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	0	200
Licensing Agreements [Member] | Nationwide Children's Hospital [Member] | Mustang [Member] | MB-108 (C134 Oncolytic Virus for GBM [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired		200
Licensing Agreements [Member] | CSL Behring [Member] | Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	170	200
Licensing Agreements [Member] | CSL Behring [Member] | Mustang [Member] | MB-107 (XSCID) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	200	200
Licensing Agreements [Member] | University of California [Member] | Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	0	300
Licensing Agreements [Member] | University of California [Member] | Mustang [Member] | MB-105 (PSCA CAR T) [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	200	0
Licensing Agreements [Member] | SIRION Biotech [Member] | Mustang [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development - licenses acquired	$ 117	$ 0

Sponsored Research and Clinic_3

Sponsored Research and Clinical Trial Agreements (Narrative) (Details) £ in Millions

Dec. 16, 2020USD ($)

Jul. 24, 2018USD ($)

Mar. 17, 2018USD ($)

Jan. 25, 2018USD ($)

Jan. 03, 2018USD ($)

Nov. 30, 2017USD ($)

Nov. 28, 2017USD ($)

Feb. 17, 2017USD ($)

Mar. 31, 2015USD ($)installment

Jan. 31, 2021USD ($)

Jan. 31, 2021GBP (£)

Oct. 31, 2020USD ($)

Jun. 30, 2020USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Dec. 16, 2020GBP (£)

Nov. 30, 2020USD ($)

Sep. 30, 2020USD ($)

May 31, 2020USD ($)

Jul. 03, 2017USD ($)

Oct. 31, 2016USD ($)

Research and development expenses

$ 64,109,000

$ 81,326,000

Research and Clinical Trial Agreements [Member] | Aevitas [Member] | AAV Gene Therapies [Member]

Research and development expenses

948,000

1,133,000

Research and Clinical Trial Agreements [Member] | Aevitas [Member] | University of Massachusetts [Member]

Sponsored research agreement, funding commitment

$ 700,000

Research and Clinical Trial Agreements [Member] | Aevitas [Member] | University of Massachusetts [Member] | Within 30 days of Execution [Member]

Sponsored research agreement, funding commitment

$ 400,000

Research and Clinical Trial Agreements [Member] | Aevitas [Member] | University of Massachusetts [Member] | AAV Gene Therapies [Member]

Payments for research and development expenses

$ 800,000

Sponsored research agreement, funding commitment

$ 800,000

Research and development expenses

381,000

0

Research and Clinical Trial Agreements [Member] | Aevitas [Member] | University of Pennsylvania [Member] | AAV Gene Therapies [Member]

Payments for research and development expenses

$ 300,000

Sponsored research agreement, funding commitment

$ 2,000,000

Research and development expenses

567,000

1,067,000

Research and Clinical Trial Agreements [Member] | Aevitas [Member] | Duke University School of Medicine [Member] | AAV Gene Therapies [Member]

Research and development expenses

0

66,000

Research and Clinical Trial Agreements [Member] | Cellvation [Member] | University of Texas [Member]

Sponsored research agreement, funding commitment

$ 800,000

Research and development expenses

0

100,000

Research and Clinical Trial Agreements [Member] | Mustang [Member]

Research and development expenses

7,717,000

6,143,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member]

Sponsored research agreement, funding commitment

$ 2,000,000

Research and development expenses

500,000

2,000,000

Number of installments to pay the upfront fees | installment

4

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-102 (CD 123 CAR T for AML) [Member]

Sponsored research agreement, additional funding commitment

$ 100,000

Research and development expenses

433,000

1,202,000

Upfront fees payment

20,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-102 (CD 123 CAR T for AML) [Member] | Over Three Years [Member]

Sponsored research agreement, additional funding commitment

200,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-104 (CS1 CAR T) [Member]

Research and development expenses

885,000

0

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-101 (IL13R2 CAR T for Glioblastoma) [Member]

Sponsored research agreement, additional funding commitment

100,000

Research and development expenses

530,000

876,000

Upfront fees payment

$ 9,300

$ 29,375

Payments of milestones

100,000

Funding commitment period

3 years

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-101 (IL13R2 CAR T for Glioblastoma) [Member] | Over Three Years [Member]

Research and development expenses

$ 200,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-101 (IL13R2 CAR T for Glioblastoma) [Member] | Clinical Development and Regulatory Milestones [Member]

Payments of milestones

200,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-103 (HER2 CAR T) [Member]

Sponsored research agreement, funding commitment

$ 29,375

Research and development expenses

1,519,000

0

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-105 (PSCA CAR T) [Member]

Sponsored research agreement, funding commitment

33,000

Research and development expenses

204,000

0

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | Manufacturing License [Member]

Sponsored research agreement, funding commitment

$ 900,000

Research and development expenses

0

457,000

Funding commitment period

2 years

Research and Clinical Trial Agreements [Member] | Mustang [Member] | City of Hope (COH) [Member] | MB-107 (XSCID) [Member]

Sponsored research agreement, funding commitment

800,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Beth Israel Deaconess Medical Center Inc. [Member] | CRISPR (multiple programs) [Member]

Research and development expenses

0

69,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Beth Israel Deaconess Medical Center Inc. [Member] | CRISPR (multiple programs) [Member] | Over Three Years [Member]

Sponsored research agreement, funding commitment

$ 800,000

Funding commitment period

3 years

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Fred Hutchinson Cancer Research Center [Member] | Manufacturing License [Member]

Payments for research and development expenses

$ 600,000

0

200,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Fred Hutchinson Cancer Research Center [Member] | MB-106 (CD20 CAR T) [Member]

Research and development expenses

1,804,000

762,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | St. Jude Children's Research Hospital [Member] | MB-107 (XSCID) [Member]

Research and development expenses

1,842,000

777,000

Upfront fees payment

$ 1,100,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Maximum [Member] | City of Hope (COH) [Member] | MB-104 (CS1 CAR T) [Member]

Sponsored research agreement, funding commitment

$ 2,400,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Maximum [Member] | City of Hope (COH) [Member] | MB-103 (HER2 CAR T) [Member]

Sponsored research agreement, funding commitment

$ 3,000,000

Research and Clinical Trial Agreements [Member] | Mustang [Member] | Maximum [Member] | City of Hope (COH) [Member] | MB-105 (PSCA CAR T) [Member]

Sponsored research agreement, funding commitment

$ 2,300,000

Research and Clinical Trial Agreements [Member] | Oncogenuity [Member] | Columbia University [Member]

Research and development expenses

$ 500,000

0

Funding commitment period

5 years

Research and Clinical Trial Agreements [Member] | Oncogenuity [Member] | University of Oxford [Member]

Funding commitment period

18 months

Research and Clinical Trial Agreements [Member] | Oncogenuity [Member] | University of Oxford [Member] | Subsequent Events [Member]

Upfront fees payment

$ 100,000

£ 0.1

Research and Clinical Trial Agreements [Member] | Oncogenuity [Member] | Maximum [Member] | Columbia University [Member]

Sponsored research agreement, funding commitment

$ 4,800,000

Research and Clinical Trial Agreements [Member] | Oncogenuity [Member] | Maximum [Member] | University of Oxford [Member]

Sponsored research agreement, funding commitment

$ 600,000

£ 0.4

Research and Clinical Trial Agreements [Member] | Tamid [Member] | University of North Carolina [Member]

Research and development expenses

0

0

Upfront fees payment

$ 800,000

Research and Clinical Trial Agreements [Member] | Tamid [Member] | University of North Carolina [Member] | Over Three Years [Member]

Sponsored research agreement, funding commitment

$ 2,300,000

Funding commitment period

3 years

Clinical Trial Agreements [Member] | Mustang [Member] | Fred Hutchinson Cancer Research Center [Member] | MB-106 (CD20 CAR T) [Member]

Sponsored research agreement, additional funding commitment

$ 800,000

Research and development expenses

$ 1,800,000

$ 600,000

Clinical Trial Agreements [Member] | Mustang [Member] | Maximum [Member] | Fred Hutchinson Cancer Research Center [Member] | MB-106 (CD20 CAR T) [Member]

Sponsored research agreement, funding commitment

$ 5,300,000

Sponsored Research and Clinic_4

Sponsored Research and Clinical Trial Agreements (Schedule of Research and Development for Sponsored Research and Clinical Trial Agreements) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Research and Development Expense	$ 64,109	$ 81,326
Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	7,717	6,143
AAV Gene Therapies [Member] | Research and Clinical Trial Agreements [Member] | Aevitas [Member]
Research and Development Expense	948	1,133
City of Hope (COH) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	500	2,000
City of Hope (COH) [Member] | MB-102 (CD 123 CAR T for AML) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	433	1,202
City of Hope (COH) [Member] | MB-101 (IL13R2 CAR T for Glioblastoma) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	530	876
City of Hope (COH) [Member] | Manufacturing License [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	0	457
City of Hope (COH) [Member] | MB-104 (CS1 CAR T) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	885	0
City of Hope (COH) [Member] | MB-103 (HER2 CAR T) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	1,519	0
City of Hope (COH) [Member] | MB-105 (PSCA CAR T) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	204	0
Beth Israel Deaconess Medical Center Inc. [Member] | CRISPR (multiple programs) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	0	69
St. Jude Children's Research Hospital [Member] | MB-107 (XSCID) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	1,842	777
Fred Hutchinson Cancer Research Center [Member] | MB-106 (CD20 CAR T) [Member] | Research and Clinical Trial Agreements [Member] | Mustang [Member]
Research and Development Expense	1,804	762
University of Massachusetts [Member] | AAV Gene Therapies [Member] | Research and Clinical Trial Agreements [Member] | Aevitas [Member]
Research and Development Expense	381	0
University of Pennsylvania [Member] | AAV Gene Therapies [Member] | Research and Clinical Trial Agreements [Member] | Aevitas [Member]
Research and Development Expense	567	1,067
Duke University School of Medicine [Member] | AAV Gene Therapies [Member] | Research and Clinical Trial Agreements [Member] | Aevitas [Member]
Research and Development Expense	$ 0	$ 66

Intangibles (Narrative) (Detail

Intangibles (Narrative) (Details)

Jan. 01, 2022USD ($)

Jul. 01, 2021USD ($)

Apr. 01, 2021USD ($)

Jan. 01, 2021USD ($)

Dec. 18, 2020USD ($)installment

Jun. 29, 2020USD ($)Milestone

Jul. 22, 2019USD ($)Milestone

Aug. 31, 2018

Jan. 31, 2016USD ($)

Mar. 31, 2015USD ($)

Dec. 31, 2022USD ($)

Dec. 31, 2021USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2018USD ($)

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

$ 500,000

$ 0

Amortization of intangible assets

1,420,000

1,174,000

Intangible asset, net

14,629,000

7,377,000

$ 1,417,000

Purchase of intangible asset

1,200,000

2,400,000

Anti-itch Product [Member]

Finite-Lived Intangible Assets [Line Items]

Total consideration

$ 4,000,000

Asset purchase agreement, non refundable deposit

$ 200,000

Installment payment related to intangible asset

$ 1,800,000

Number of installments to pay the upfront fees | installment

3

Amortization of intangible assets

0

Initial discount for imputed interest

$ 100,000

Intangible assets, estimated useful lives

3 years

Anti-itch Product [Member] | Scenario, Plan [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

$ 1,000,000

$ 500,000

$ 500,000

$ 1,000,000

$ 2,800,000

Oral Acne Product (Isotretinoin) [Member]

Finite-Lived Intangible Assets [Line Items]

Total consideration

$ 5,000,000

Installment payment related to intangible asset

$ 3,500,000

500,000

Number of installments to pay the upfront fees | installment

3

Upfront payment payable

1,000,000

Amortization of intangible assets

0

Initial discount for imputed interest

$ 300,000

Intangible assets, estimated useful lives

5 years

Oral Acne Product (Isotretinoin) [Member] | Regulatory Approvals to Commercialize the Products [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

$ 500,000

Oral Acne Product (Isotretinoin) [Member] | Upon the Delivery of the First Order [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

500,000

Oral Acne Product (Isotretinoin) [Member] | Anniversary of Execution of the Oral Acne Agreement [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

3,000,000

Oral Acne Product (Isotretinoin) [Member] | On the 18-month Anniversary [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

1,000,000

Oral Acne Product (Isotretinoin) [Member] | On the 24-month Anniversary [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

1,000,000

Oral Acne Product (Isotretinoin) [Member] | On the 36-month Anniversary [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

1,000,000

Oral Acne Product (Isotretinoin) [Member] | Achievement of Certain Sales Milestones [Member]

Finite-Lived Intangible Assets [Line Items]

Installment payment related to intangible asset

$ 17,000,000

Number of installments to pay the upfront fees | Milestone

3

Luxamend [Member]

Finite-Lived Intangible Assets [Line Items]

Upfront payment payable

$ 50,000

Upfront fees payment

$ 300,000

Intangible assets, estimated useful lives

3 years

Targadox [Member]

Finite-Lived Intangible Assets [Line Items]

Upfront fees payment

$ 1,300,000

Ximino [Member]

Finite-Lived Intangible Assets [Line Items]

Total consideration

$ 9,400,000

Installment payment related to intangible asset

$ 7,000,000

Number of installments to pay the upfront fees | Milestone

4

Upfront payment payable

$ 2,400,000

Intangible asset, net

5,690,000

$ 7,100,000

Initial discount for imputed interest

$ 2,300,000

Intangible assets, estimated useful lives

7 years

Exelderm [Member]

Finite-Lived Intangible Assets [Line Items]

Intangible asset, net

$ 267,000

Intangible assets, estimated useful lives

3 years

Intangibles (Schedule of Intang

Intangibles (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total Intangible assets - asset purchases	$ 18,606	$ 9,934
Accumulated amortization	(3,977)	(2,557)
Net intangible assets	$ 14,629	$ 7,377	$ 1,417
Minimum [Member]
Intangible assets, estimated useful lives	3 years
Maximum [Member]
Intangible assets, estimated useful lives	7 years

Intangibles (Schedule of JMC Re

Intangibles (Schedule of JMC Recognized Expense Related to its Product Licenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Beginning balance	$ 7,377	$ 1,417
Research and development	2,834	6,090
Additions:		7,134
Amortization expense	(1,420)	(1,174)
Ending balance	14,629	7,377
Ximino [Member]
Finite-Lived Intangible Assets [Line Items]
Beginning balance	7,100
Ending balance	5,690	$ 7,100
Anti-itch Product [Member]
Finite-Lived Intangible Assets [Line Items]
Additions:	3,945
Amortization expense	0
Oral Acne Product (Isotretinoin) [Member]
Finite-Lived Intangible Assets [Line Items]
Additions:	4,727
Amortization expense	$ 0

Intangibles (Schedule of Future

Intangibles (Schedule of Future Amortization of Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Year Ended December 31, 2021	$ 1,286
Year Ended December 31, 2022	1,019
Year Ended December 31, 2023	1,019
Year Ended December 31, 2024	1,019
Year Ended December 31, 2025	1,019
Thereafter	595
Sub-total	5,957
Intangible assets not yet placed in service	8,672
Net intangible assets	14,629	$ 7,377	$ 1,417
Ximino [Member]
Finite-Lived Intangible Assets [Line Items]
Year Ended December 31, 2021	1,019
Year Ended December 31, 2022	1,019
Year Ended December 31, 2023	1,019
Year Ended December 31, 2024	1,019
Year Ended December 31, 2025	1,019
Thereafter	595
Sub-total	5,690
Net intangible assets	5,690	$ 7,100
Exelderm [Member]
Finite-Lived Intangible Assets [Line Items]
Year Ended December 31, 2021	267
Year Ended December 31, 2022	0
Year Ended December 31, 2023	0
Year Ended December 31, 2024	0
Year Ended December 31, 2025	0
Thereafter	0
Sub-total	267
Intangible assets not yet placed in service	0
Net intangible assets	$ 267

Debt and Interest (Narrative) (

Debt and Interest (Narrative) (Details)

Aug. 27, 2020USD ($)shares

Jan. 31, 2020

Sep. 30, 2019USD ($)

Jul. 18, 2019USD ($)$ / sharesshares

Sep. 30, 2017USD ($)$ / sharesshares

Sep. 18, 2017

Aug. 31, 2017USD ($)$ / sharesshares

Jun. 30, 2017USD ($)$ / sharesshares

May 31, 2017USD ($)$ / sharesshares

May 01, 2017USD ($)$ / sharesshares

Mar. 31, 2017USD ($)$ / sharesshares

Mar. 17, 2017

Sep. 14, 2016USD ($)$ / sharesshares

Feb. 13, 2014USD ($)

Aug. 31, 2020USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Dec. 31, 2017USD ($)$ / sharesshares

Debt Instrument [Line Items]

Debt maturity date

Sep. 14, 2018

Total notes payable

$ 51,677,000

$ 84,656,000

Fair Value Adjustment of Warrants

1,189,000

27,000

Opus Credit Facility (2019 Notes) [Member]

Debt Instrument [Line Items]

Debt instrument face amount

9,000,000

Maximum borrowing capacity

$ 25,000,000

Credit facility, amount outstanding

$ 0

9,000,000

Debt instrument, stated interest rate

12.00%

12.00%

Debt maturity date

Sep. 14, 2018

Repayments of debt

$ 21,700,000

$ 9,000,000

Total notes payable

9,000,000

Warrant expiration term

5 years

Debt instrument conversion price per share | $ / shares

$ 10

Class of warrant or right value of securities called by warrants or rights

1,500,000

Number of shares of Common Stock equal to the product | shares

1,000,000

Credit facility agreement, number by which the notes are divided by

25,000,000

Exercise price of warrants | $ / shares

$ 3

Opus Credit Facility (2019 Notes) [Member] | DAK Capital Inc. [Member]

Debt Instrument [Line Items]

Total notes payable

3,800,000

Opus Credit Facility (2019 Notes) [Member] | Chief Executive Officer (Dr. Rosenwald) [Member]

Debt Instrument [Line Items]

Repayments of debt

$ 500,000

Total notes payable

300,000

Common shares issued (in shares) | shares

396,825

Share price per share | $ / shares

$ 1.26

Opus Credit Facility (2019 Notes) [Member] | Executive Vice President (Mr. Weiss) [Member]

Debt Instrument [Line Items]

Total notes payable

2,000,000

Opus Credit Facility (2019 Notes) [Member] | Chief Executive Officer And Executive Vice President [Member]

Debt Instrument [Line Items]

Total notes payable

2,900,000

Opus Credit Facility (2019 Notes) [Member] | Event of Default [Member]

Debt Instrument [Line Items]

Debt Instrument, Interest Rate, Effective Percentage

14.00%

IDB Note Payable [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

2.25%

Repayments of debt

$ 14,858,000

0

IDB Note Payable [Member] | Promissory Note [Member]

Debt Instrument [Line Items]

Maximum borrowing capacity

$ 15,000,000

Amount outstanding

14,000,000

$ 0

$ 14,900,000

Remaining borrowing capacity

$ 100,000

Debt instrument, stated interest rate

2.25%

Basis spread on variable rate

1.50%

Collateral amount

$ 15,000,000

Debt maturity date

Aug. 1, 2021

Aug. 1, 2020

IDB Note Payable [Member] | Letter of Credit [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

2.00%

Letter of credit, amount outstanding

$ 1,600,000

2017 Subordinated Note Financing [Member]

Debt Instrument [Line Items]

Debt instrument face amount

$ 3,250,000

Maximum borrowing capacity

$ 40,000,000

Debt instrument, stated interest rate

8.00%

Repayments of debt

$ 28,400,000

28,356,000

$ 0

Total notes payable

0

28,400,000

Paid-in-kind interest rate

7.00%

Payment of debt issuance fees

$ 93,000

118,000

2017 Subordinated Note Financing [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Agency fees payment

$ 2,800,000

Repayments of debt

$ 28,400,000

Issuance of private placement, placement fees as a percentage of net proceeds

10.00%

10.00%

Additional shares | shares

716,180

Warrant expiration term

5 years

Warrants issued, percentage of aggregate principal amount of the Notes

10.00%

10.00%

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

716,180

2017 Subordinated Note Financing [Member] | May Increase Upon Sole Discretion [Member]

Debt Instrument [Line Items]

Maximum borrowing capacity

$ 50,000,000

2017 Subordinated Note Financing [Member] | Maximum [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Exercise price of warrants | $ / shares

$ 4.75

2017 Subordinated Note Financing [Member] | Minimum [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Exercise price of warrants | $ / shares

$ 3.61

2017 Subordinated Note Financing One [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

8.00%

2017 Subordinated Note Financing One [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Additional shares | shares

87,946

Proceed from closing of the 2017 Subordinated Note Financing

$ 3,200,000

Payment of debt issuance fees

$ 300,000

Exercise price of warrants | $ / shares

$ 3.70

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

87,946

2017 Subordinated Note Financing Two [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

8.00%

2017 Subordinated Note Financing Two [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Additional shares | shares

234,438

Proceed from closing of the 2017 Subordinated Note Financing

$ 8,600,000

Payment of debt issuance fees

$ 900,000

Exercise price of warrants | $ / shares

$ 3.65

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

234,438

2017 Subordinated Note Financing Three [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

8.00%

2017 Subordinated Note Financing Three [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Additional shares | shares

147,806

Proceed from closing of the 2017 Subordinated Note Financing

$ 5,300,000

Payment of debt issuance fees

$ 500,000

Exercise price of warrants | $ / shares

$ 3.61

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

147,806

2017 Subordinated Note Financing Four [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

8.00%

2017 Subordinated Note Financing Four [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Additional shares | shares

63,526

38,315

Proceed from closing of the 2017 Subordinated Note Financing

$ 3,000,000

$ 1,800,000

Payment of debt issuance fees

$ 300,000

$ 200,000

Exercise price of warrants | $ / shares

$ 4.75

$ 4.75

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

63,526

38,315

2017 Subordinated Note Financing Five [Member]

Debt Instrument [Line Items]

Debt instrument, stated interest rate

8.00%

2017 Subordinated Note Financing Six [Member] | National Securities Corporation ("NSC") [Member]

Debt Instrument [Line Items]

Additional shares | shares

144,149

Proceed from closing of the 2017 Subordinated Note Financing

$ 6,400,000

Payment of debt issuance fees

$ 600,000

Exercise price of warrants | $ / shares

$ 4.42

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

144,149

Oaktree Note [Member]

Debt Instrument [Line Items]

Debt instrument face amount

$ 60,000,000

Debt instrument, stated interest rate

11.00%

11.00%

Debt maturity date

Aug. 27, 2025

Percentage of upfront commitment fee

3.00%

Upfront Commitment Fee

$ 1,800,000

Debt issuance fees

$ 8,700,000

Agency fees payment

35,000

Payment of expenses to third parties

$ 2,500,000

Additional shares | shares

1,749,450

Payment of debt issuance fees

$ 4,302,000

$ 0

Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares

1,749,450

Warrants, fair value

$ 4,400,000

Debt and Interest (2018 Venture

Debt and Interest (2018 Venture Notes and Mustang Horizon Notes) (Narrative) (Details)	Sep. 30, 2020USD ($)	Mar. 29, 2019USD ($)$ / sharesshares	Mar. 29, 2019USD ($)installment$ / sharesshares	Mar. 31, 2018USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Debt maturity date					Sep. 14, 2018
Cash balance					$ 13,000,000
Total notes payable, gross					60,000,000	$ 89,742,000
Debt instrument, accrued interest					$ 9,704,000	8,528,000
LIBOR Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate					2.50%
2018 Venture Notes [Member]
Debt Instrument [Line Items]
Payment of debt issuance fees					$ 58,000	134,000
Proceeds from Notes						2,000,000
Debt repayment terms							will be repaid at the rate of 1/12 of the principal amount per month for a period of 12 months. Interest on the note is 8% payable quarterly during the first 24 months (or the first 30 months if the note is extended) and monthly during the last 12 months
Debt instrument, stated interest rate							8.00%
Total notes payable, gross					0	21,700,000
Repayments of debt					21,707,000	0
Debt instrument, accrued interest					$ 1,253,000	1,737,000
2018 Venture Notes [Member] | National Securities Corporation ("NSC") [Member]
Debt Instrument [Line Items]
Warrant expiration term					10 years
Warrant on Sale Price of Note Percentage					25.00%
2018 Venture Notes [Member] | Promissory Note [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 21,700,000
Proceeds from Notes							21,700,000
2018 Venture Notes [Member] | Promissory Note [Member] | National Securities Corporation ("NSC") [Member]
Debt Instrument [Line Items]
Payment of debt issuance fees				$ 1,700,000
Venture Note One [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate					8.00%
Total notes payable, gross					$ 0	6,517,000
Venture Note Two [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate					8.00%
Total notes payable, gross					$ 0	15,190,000
Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Term		42 months
Payment of debt issuance fees					$ 0	1,393,000
Warrant expiration term		10 years	10 years
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 900,000	$ 900,000
Debt maturity date		Oct. 1, 2022
Commitment fee amount		$ 200,000
Percentage of Warrants Included in Debt		5.00%
Reimbursement of Legal Fees		$ 30,000
Maximum borrowing capacity		20,000,000	20,000,000
Remaining borrowing capacity		5,000,000	5,000,000
Legal fees		1,200,000
Debt instrument face amount		$ 15,000,000	$ 15,000,000
Debt instrument, stated interest rate					9.00%
Amortization payments, installments | installment			18
Percent of Outstanding Loan Principal Amount for Calculation of Repayment Change			4.00%
Percentage Of Amortization Loan Date			3.00%
Exercise price of warrants | $ / shares		$ 3.47	$ 3.47
Number of shares called by warrants | shares		288,184	288,184
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate		2.00%	2.00%
Additional Rate Of Accrued Interest Percentage			5.00%
Debt redemption, prepayment of debt amount		$ 250,000
Debt Prepayment Penalties	$ 600,000				$ 600,000
Final payment fee	800,000
Total notes payable, gross					0	15,750,000
Repayments of debt	15,000,000				15,750,000	0
Debt instrument, accrued interest	$ 100,000				$ 1,585,000	$ 1,042,000
Mustang Horizon Notes [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate						9.00%
Basis spread on variable rate						2.50%
Tamid [Member] | 2018 Venture Notes [Member]
Debt Instrument [Line Items]
Proceeds from Notes						$ 1,600,000
Aevitas [Member] | 2018 Venture Notes [Member]
Debt Instrument [Line Items]
Proceeds from Notes						3,800,000
Cyprium [Member] | 2018 Venture Notes [Member]
Debt Instrument [Line Items]
Proceeds from Notes						$ 2,200,000
Maximum [Member] | Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Cash balance		13,000,000	$ 13,000,000
Minimum [Member] | Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Cash balance		$ 8,000,000	$ 8,000,000
First 24 Months the Company May Extend the Maturity Date by Six Months [Member] | 2018 Venture Notes [Member]
Debt Instrument [Line Items]
Principal payment due							$ 0
First 24 Months the Company May Extend the Maturity Date by Six Months [Member] | 2018 Venture Notes [Member] | Promissory Note [Member]
Debt Instrument [Line Items]
Debt Instrument, Term							36 months
LIBOR Rate Exceeds 2.50% [Member] | Mustang Horizon Notes [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, stated interest rate		9.00%	9.00%
Prepayment charge of 4.0% [Member] | Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Debt redemption, prepayment of debt amount			$ 500,000
Final Payment [Member] | Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Debt redemption, prepayment of debt amount			250,000
Aggregate Final Payment [Member] | Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Principal payment due			$ 750,000

Debt and Interest (Schedule of

Debt and Interest (Schedule of Debt) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Aug. 27, 2020	Mar. 29, 2019	Dec. 31, 2018	Mar. 31, 2017	Sep. 14, 2016
Debt Instrument [Line Items]
Total notes payable, gross	$ 60,000	$ 89,742
Less: Discount of notes payable	8,323	5,086
Long-term Debt, Total	51,677	84,656
Notes payable, short-term	$ 0	7,220
LIBOR Rate [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.50%
IDB Note Payable [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	14,929
Interest Rate	2.25%
Maturity Date, description	Aug - 2021
2017 Subordinated Note Financing [Member]
Debt Instrument [Line Items]
Less: Discount of notes payable	$ 1,200
Long-term Debt, Total	$ 0	28,400
Interest Rate						8.00%
2017 Subordinated Note Financing [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Interest Rate	9.00%
2017 Subordinated Note Financing One [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	3,254
Interest Rate	8.00%
Maturity Date, description	March - 2022
2017 Subordinated Note Financing Two [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	13,893
Interest Rate	8.00%
Maturity Date, description	May - 2022
2017 Subordinated Note Financing Three [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	1,820
Interest Rate	8.00%
Maturity Date, description	June - 2022
2017 Subordinated Note Financing Four [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	3,018
Interest Rate	8.00%
Maturity Date, description	August - 2022
2017 Subordinated Note Financing Five [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	6,371
Interest Rate	8.00%
Maturity Date, description	September - 2022
2018 Venture Notes [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	21,700
Less: Discount of notes payable	300
Interest Rate					8.00%
Notes payable, short-term		6,000
Venture Note One [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	6,517
Interest Rate	8.00%
Maturity Date, description	August - 2021
Venture Note Two [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	15,190
Interest Rate	8.00%
Maturity Date, description	September - 2021
Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	15,750
Less: Discount of notes payable	$ 1,800
Interest Rate	9.00%
Maturity Date, description	October - 2022
Notes payable, short-term		$ 1,200
Mustang Horizon Notes [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Interest Rate		9.00%
Basis spread on variable rate		2.50%
Mustang Horizon Notes [Member] | LIBOR Rate Exceeds 2.50% [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Interest Rate				9.00%
Oaktree Note [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 60,000	$ 0
Interest Rate	11.00%		11.00%
Maturity Date, description	August - 2025
Opus Credit Facility (2019 Notes) [Member]
Debt Instrument [Line Items]
Total notes payable, gross	$ 0	9,000
Long-term Debt, Total		$ 9,000
Interest Rate	12.00%						12.00%
Maturity Date, description	September - 2021

Debt and Interest (Interest Exp

Debt and Interest (Interest Expense) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Interest expense, interest		$ 9,704	$ 8,528
Amortization of fees		5,622	3,321
Interest expense, Total		15,326	11,849
Unamortized debt discount fees		8,323	5,086
Opus Credit Facility (2019 Notes) [Member]
Debt Instrument [Line Items]
Interest expense, interest		710	1,113
Amortization of fees		0	336
Interest expense, Total		710	1,449
Letter of Credit [Member]
Debt Instrument [Line Items]
Interest expense, interest		34	60
Amortization of fees		0	0
Interest expense, Total		34	60
IDB Note Payable [Member]
Debt Instrument [Line Items]
Interest expense, interest		246	356
Amortization of fees		0
Interest expense, Total		246	356
2017 Subordinated Note Financing [Member]
Debt Instrument [Line Items]
Interest expense, interest		2,870	4,220
Amortization of fees		1,890	1,381
Interest expense, Total		4,760	5,601
Unamortized debt discount fees		1,200
2018 Venture Notes [Member]
Debt Instrument [Line Items]
Interest expense, interest		1,253	1,737
Amortization of fees		1,000	639
Interest expense, Total		2,253	2,376
Unamortized debt discount fees		300
Mustang Horizon Notes [Member]
Debt Instrument [Line Items]
Interest expense, interest	$ 100	1,585	1,042
Amortization of fees		2,321	710
Interest expense, Total		3,906	1,752
Unamortized debt discount fees		1,800
Debt prepayment penalties	$ 600	600
Oaktree Note [Member]
Debt Instrument [Line Items]
Interest expense, interest		2,311	0
Amortization of fees		411	0
Interest expense, Total		2,722	0
NSC Note [Member]
Debt Instrument [Line Items]
Interest expense, interest		697	0
Amortization of fees		0	255
Interest expense, Total		697	255
Other Debt [Member]
Debt Instrument [Line Items]
Interest expense, interest			0
Amortization of fees		0	0
Interest expense, Total			$ 0
Interest expense (income)		$ (2)

Accrued Liabilities and other_3

Accrued Liabilities and other Long-Term Liabilities (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 18, 2020	Jun. 29, 2020	Jul. 22, 2019
Long-term notes payable, net (Journey)	$ 51,677	$ 77,436
Amortization of interest discount	5,622	3,321
Notes payable, short-term	0	7,220
Ximino [Member]
Initial discount for imputed interest					$ 2,300
Ximino [Member] | Journey [Member]
Initial discount for imputed interest		2,300
Long-term notes payable, net (Journey)		$ 4,700
Effective interest rate used to calculated imputed interest discount (in percent)		11.96%
Period of effective interest rate considered for calculation of imputed interest discount (in years)		5 years
Amortization of interest discount	600	$ 300
Notes payable, short-term	2,000
Oral Acne Product (Isotretinoin) [Member]
Initial discount for imputed interest				$ 300
Oral Acne Product (Isotretinoin) [Member] | Journey [Member]
Initial discount for imputed interest	300
Long-term notes payable, net (Journey)	$ 3,700
Effective interest rate used to calculated imputed interest discount (in percent)	4.00%
Period of effective interest rate considered for calculation of imputed interest discount (in years)	3 years
Amortization of interest discount	$ 100
Notes payable, short-term	500
Anti-itch Product [Member]
Initial discount for imputed interest			$ 100
Anti-itch Product [Member] | Journey [Member]
Initial discount for imputed interest	100
Long-term notes payable, net (Journey)	$ 3,700
Effective interest rate used to calculated imputed interest discount (in percent)	4.25%
Period of effective interest rate considered for calculation of imputed interest discount (in years)	3 years
Notes payable, short-term	$ 2,800

Accrued Liabilities and other_4

Accrued Liabilities and other Long-Term Liabilities (Schedule of Accrued Expenses and Other Long-Term Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accrued expenses:
Professional fees	$ 1,236	$ 1,153
Salaries, bonus and related benefits	6,701	6,683
Research and development	5,007	4,215
Research and development - manufacturing	518	1,017
Research and development - license maintenance fees	461	361
Research and development - milestones	600	0
Accrued royalties payable	2,682	2,320
Accrued coupon expense	10,869	8,391
Other	1,188	1,259
Total accrued expenses	29,262	25,399
Other long-term liabilities:
Deferred rent and long-term lease abandonment charge	1,949	2,136
Partner company note payable, long-term	7,359	4,990
Total other long-term liabilities and partner company note payable, long-term	9,308	7,126
Ximino [Member]
Other long-term liabilities:
Partner company note payable, long-term	3,622	4,990
Oral Acne Product (Isotretinoin) [Member]
Other long-term liabilities:
Partner company note payable, long-term	2,792	0
Anti-itch Product [Member]
Other long-term liabilities:
Partner company note payable, long-term	$ 945	$ 0

Non-Controlling Interests (Sche

Non-Controlling Interests (Schedule of Non-Controlling Interests in Consolidated Entities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Noncontrolling Interest [Line Items]
NCI equity share	$ 153,120	$ 108,017
Net loss attributable to non-controlling interests	(56,459)	(61,700)
Non-controlling interests in consolidated entities	96,661	46,317
Acquisition Corp VIII [Member]
Noncontrolling Interest [Line Items]
NCI equity share	(7)
Net loss attributable to non-controlling interests	(27)
Non-controlling interests in consolidated entities	$ (34)
Non-controlling ownership	10.00%
Aevitas [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (2,370)	(1,249)
Net loss attributable to non-controlling interests	(823)	(694)
Non-controlling interests in consolidated entities	$ (3,193)	$ (1,943)
Non-controlling ownership	39.00%	35.80%
Avenue [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ 5,800	$ 24,269
Net loss attributable to non-controlling interests	(3,974)	(19,011)
Non-controlling interests in consolidated entities	$ 1,826	$ 5,258
Non-controlling ownership	77.40%	77.30%
Baergic [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (1,662)	$ 23
Net loss attributable to non-controlling interests	(97)	(1,162)
Non-controlling interests in consolidated entities	$ (1,759)	$ (1,139)
Non-controlling ownership	39.50%	33.00%
Cellvation [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (1,089)	$ (732)
Net loss attributable to non-controlling interests	(182)	(158)
Non-controlling interests in consolidated entities	$ (1,271)	$ (890)
Non-controlling ownership	22.10%	20.60%
Checkpoint [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ 41,704	$ 29,389
Net loss attributable to non-controlling interests	(13,265)	(14,687)
Non-controlling interests in consolidated entities	$ 28,439	$ 14,702
Non-controlling ownership	80.40%	78.00%
Coronado SO [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (290)	$ (290)
Net loss attributable to non-controlling interests	0	0
Non-controlling interests in consolidated entities	$ (290)	$ (290)
Non-controlling ownership	13.00%	13.00%
Cyprium [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ 567	$ (320)
Net loss attributable to non-controlling interests	(1,478)	(99)
Non-controlling interests in consolidated entities	$ (911)	$ (419)
Non-controlling ownership	30.50%	10.60%
Helocyte [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (4,986)	$ (4,322)
Net loss attributable to non-controlling interests	(259)	(402)
Non-controlling interests in consolidated entities	$ (5,245)	$ (4,724)
Non-controlling ownership	18.80%	19.30%
JMC [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ 138	$ (211)
Net loss attributable to non-controlling interests	491	325
Non-controlling interests in consolidated entities	$ 629	$ 114
Non-controlling ownership	7.10%	6.90%
Mustang [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ 116,060	$ 62,025
Net loss attributable to non-controlling interests	(36,429)	(25,727)
Non-controlling interests in consolidated entities	$ 79,631	$ 36,298
Non-controlling ownership	80.90%	70.30%
Oncogenuity [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (82)
Net loss attributable to non-controlling interests	(376)
Non-controlling interests in consolidated entities	$ (458)
Non-controlling ownership	25.30%
Tamid [Member]
Noncontrolling Interest [Line Items]
NCI equity share	$ (663)	$ (565)
Net loss attributable to non-controlling interests	(40)	(85)
Non-controlling interests in consolidated entities	$ (703)	$ (650)
Non-controlling ownership	22.80%	22.80%

Net Loss per Common Share (Narr

Net Loss per Common Share (Narrative) (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Net Loss per Common Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	19,216,795	18,293,739

Net Loss per Common Share (Sche

Net Loss per Common Share (Schedule of Diluted Weighted Average Shares Outstanding) (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from the computations of diluted weighted average shares outstanding	19,216,795	18,293,739
Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from the computations of diluted weighted average shares outstanding	3,419,812	2,729,186
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from the computations of diluted weighted average shares outstanding	1,103,643	1,179,680
Convertible preferred stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from the computations of diluted weighted average shares outstanding	0	1,038,251
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from the computations of diluted weighted average shares outstanding	14,302,004	12,625,144
Unvested Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from the computations of diluted weighted average shares outstanding	391,336	721,478

Stockholders' Equity (Common St

Stockholders' Equity (Common Stock and Preferred Stock) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2017
Common stock, increase in shares authorized	50,000,000
Common Stock, shares authorized	150,000,000	100,000,000
Common Stock, par value	$ 0.001	$ 0.001
Common Stock, shares outstanding	94,877,492	74,027,425
Preferred Stock, Shares Authorized	15,000,000	15,000,000
Preferred Stock, par value	$ 0.001	$ 0.001
Preferred Stock, shares issued	3,427,138	1,341,167
Preferred Stock, shares outstanding	3,427,138	1,341,167
Preferred Stock, liquidation preference per share	$ 25	$ 25
Series A Preferred Stock [Member]
Preferred Stock, Shares Authorized	5,000,000
Preferred Stock, par value	$ 0.001
Preferred Stock, shares issued		1,341,167
Preferred Stock, shares outstanding	3,427,138
Preferred Stock, dividend rate percentage	9.375%
Preferred Stock, dividend payable per share per annum	$ 2.34375		$ 0.299479
Preferred Stock, quarterly dividend rate per share	$ 0.5839375
Preferred Stock dividends	$ 6.5	$ 2.6
Preferred Stock, Redemption Terms	may be redeemed in whole or in part (at the Company’s option) any time on or after December 15, 2022, upon not less than 30 days nor more than 60 days
Preferred Stock, redemption price per share	$ 25
Preferred Stock, liquidation preference per share	25
Series A Preferred Stock [Member] | Change of Control [Member]
Preferred Stock, redemption price per share	25
Preferred Stock, liquidation preference per share	$ 25
Preferred Stock to common stock conversion ratio	13.05483

Stockholders' Equity (Stock Bas

Stockholders' Equity (Stock Based Compensation) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2015	Aug. 27, 2020	Dec. 31, 2018	Dec. 31, 2016	Dec. 31, 2013	Dec. 31, 2007
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period			10 years
Stock-based compensation expense			$ 13,451	$ 13,188
Stock-based compensation expense			$ 13,451	$ 13,188
Outstanding warrants			4,590,621	2,741,180			2,754,189
Payments of Stock Issuance Costs			$ 1,658	$ 427
Proceeds from Issuance of Preferred Stock and Preference Stock			$ 39,075	$ 6,038
Common Stock, Shares, Outstanding			94,877,492	74,027,425
Common Stock, Value, Issued			$ 95	$ 74
Revenue from Contract with Customer, Including Assessed Tax			$ 44,531	34,921
Consulting Agreements [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			100,000
Additional shares			100,000
Oaktree Note [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights						1,749,450
Additional shares						1,749,450
2007 and 2013 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation, number of shares granted			14,721,911
Stock based compensation, shares available for issuance			4,278,089
2013 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, number of shares authorized					13,000,000				2,300,000
Share based compensation, additional shares authorized			3,000,000		7,700,000
2012 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Predetermined fair value percentage during offering period			85.00%
Shares purchased in connection with the ESPP offering			577,301
Number of shares available for future issuance			422,699
Stock-based compensation expense			$ 100	100
Long-term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of stock granted			$ 2,100	600
LTIP, Percentage of outstanding shares			1.00%
Long-Term Incentive Program condition, increase in market capitalization			$ 100,000
Stock-based compensation expense			$ 2,500	1,400
Maximum [Member] | 2007 and 2013 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, shares available for issuance								19,000,000
Maximum [Member] | 2007 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, number of shares authorized										6,000,000
Chief Executive Officer (Dr. Rosenwald) [Member] | Long-term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted	801,536
Executive Vice President (Mr. Weiss) [Member] | Long-term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted		648,204
Employees and Non-Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted			600,000
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, unrecognized compensation expense				0
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options				0
Employee Stock Option [Member] | Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			$ 3,200	2,800
Employee Stock Option [Member] | General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense			10,300	10,400
Restricted Stock Awards and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of stock granted			2,000	2,000
Stock-based compensation expense			$ 12,500	$ 11,500
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period			4 years 1 month 6 days
Number of shares Granted			1,873,072	1,546,408
Fair value of stock granted			$ 4,800	$ 1,400
Unrecognized compensation expense			$ 12,600
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 2.57	$ 0.88
Restricted Stock [Member] | Executives and Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted			1,900,000	1,500,000
Restricted Stock [Member] | Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred compensation plan, shares issued			230,000	230,000
Restricted Stock [Member] | Employees and Non-Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted				300,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation, vesting period			2 years 9 months 18 days
Number of shares Granted			630,126	290,000
Fair value of stock granted			$ 2,400	$ 400
Unrecognized compensation expense			$ 3,100
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value			$ 3.82	$ 1.49
Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense			$ 0
Stock-based compensation expense			$ 130	$ 97
Performance-based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted			100,000

Stockholders' Equity (Capital R

Stockholders' Equity (Capital Raise) (Narrative) (Details) - USD ($)	Oct. 23, 2020	Aug. 28, 2020	Aug. 26, 2020	Jun. 11, 2020	May 09, 2020	Feb. 14, 2020	Aug. 16, 2019	Jul. 13, 2018	Dec. 01, 2016	Nov. 30, 2020	Sep. 30, 2020	Nov. 30, 2019	Apr. 30, 2019	Nov. 30, 2017	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate fees paid																$ 1,658,000	$ 427,000
Preferred Stock, liquidation preference per share																$ 25	$ 25
Common Stock [Member] | MLV & Co. and FBR Capital Markets & Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, price per share																	$ 1.88
Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued																		0
Preferred Stock, dividend rate percentage																9.375%
Preferred Stock, liquidation preference per share																$ 25
Cyprium [Member] | Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, dividend rate percentage																9.375%
Preferred Stock, dividend per share															$ 0.19531
Preferred stock, dividend paid															$ 49,883	$ 200,000
Mustang [Member] | Common Stock [Member] | Cantor Fitzgerald & Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued				10,769,231
Option to purchase additional shares, exercised				686,373
Option to purchase additional number of shares				1,615,384
Stock offering, price per share				$ 3.25
Stock offering, gross proceeds				$ 37,200,000
Sale of stock, net proceeds				34,800,000
Stock offering, aggregate fees paid				$ 2,400,000
At the Market Offering [Member] | Common Stock [Member] | MLV & Co. and FBR Capital Markets & Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued																	8,000,000
Stock offering, gross proceeds																	$ 15,100,000
Stock offering, aggregate fees paid																	$ 300,000
Stock offering, sales agreement termination date									Aug. 17, 2019
At the Market Offering [Member] | Common Stock [Member] | Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., Jones Trading Institutional Services LLC and B. Riley [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued																17,400,000	3,800,000
Stock offering, price per share																$ 2.73	$ 1.49
Stock offering, gross proceeds																$ 47,500,000	$ 5,600,000
Stock offering, aggregate fees paid																$ 1,400,000	$ 200,000
At the Market Offering [Member] | Series A Preferred Stock [Member] | B. Riley, National Securities Corporation, LifeSci Capital LLC, Maxim Group LLC and Noble Capital Markets, Inc [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued																	39,292
Stock offering, price per share																	$ 20.67
Stock offering, gross proceeds																	$ 800,000
Stock offering, aggregate fees paid																	$ 24,000
Stock offering, sales agreement termination date																Dec. 1, 2019
At the Market Offering [Member] | Mustang [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued																17,600,000	3,500,000
Stock offering, price per share																$ 3.40	$ 6.42
Stock offering, gross proceeds																$ 59,800,000	$ 22,500,000
Sale of stock, net proceeds																58,700,000	22,000,000
Stock offering, aggregate fees paid																1,100,000	$ 500,000
At the Market Offering [Member] | Maximum [Member] | Common Stock [Member] | MLV & Co. and FBR Capital Markets & Co [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement									$ 53,000,000
At the Market Offering [Member] | Maximum [Member] | Common Stock [Member] | Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., Jones Trading Institutional Services LLC and B. Riley [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, commission rate																	3.00%
At the Market Offering [Member] | Maximum [Member] | Series A Preferred Stock [Member] | B. Riley, National Securities Corporation, LifeSci Capital LLC, Maxim Group LLC and Noble Capital Markets, Inc [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, commission rate																	7.00%
Public Offering [Member] | Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued			666,666		555,556	625,000						262,500
Option to purchase additional shares, exercised												39,375
Option to purchase additional number of shares			66,666		83,333	93,750
Stock offering, price per share			$ 18		$ 18	$ 20						$ 20
Stock offering, gross proceeds			$ 13,200,000		$ 11,500,000	$ 14,400,000						$ 6,000,000
Stock offering, aggregate fees paid			$ 1,100,000		$ 1,100,000	$ 1,300,000
Public Offering [Member] | Cyprium [Member] | Series A Preferred Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued		255,400
Option to purchase additional number of shares		64,600
Stock offering, price per share		$ 25
Stock offering, gross proceeds		$ 8,000,000
Stock offering, aggregate fees paid		$ 900,000
Preferred Stock, liquidation preference per share		$ 25
Public Offering [Member] | Cyprium [Member] | Series A Preferred Stock [Member] | Annual Dividend [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, dividend per share		2.34375
Public Offering [Member] | Cyprium [Member] | Series A Preferred Stock [Member] | Monthly Dividend [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred Stock, dividend per share		$ 0.19531
Public Offering [Member] | Checkpoint [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued											7,321,429	15,400,000
Stock offering, price per share											$ 2.80	$ 1.27			$ 2.80
Stock offering, gross proceeds											$ 20,500,000	$ 19,600,000
Sale of stock, net proceeds											18,900,000	17,600,000
Stock offering, aggregate fees paid											$ 1,600,000	$ 2,000,000
Public Offering [Member] | Mustang [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued													6,875,000
Option to purchase additional number of shares													1,031,250
Stock offering, price per share													$ 4
Stock offering, gross proceeds														$ 31,600,000
Sale of stock, net proceeds													$ 29,500,000
Stock offering, aggregate fees paid														2,100,000
Shelf Registration Statement [Member] | Common Stock [Member] | Cantor Fitzgerald & Co., Oppenheimer & Co., Inc., H.C. Wainwright & Co. Inc., Jones Trading Institutional Services LLC and B. Riley [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount available for future stock offerings																$ 26,700,000
Shelf Registration Statement [Member] | Checkpoint [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, commission rate										3.00%
Shelf Registration Statement [Member] | Checkpoint [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, number of shares issued																5,104,234	2,273,189
Stock offering, price per share																$ 2.50	$ 3.52
Stock offering, gross proceeds																$ 12,800,000	$ 8,000,000
Sale of stock, net proceeds																12,400,000	$ 7,800,000
Amount available for future stock offerings																83,600,000
Shelf Registration Statement [Member] | Mustang [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement	$ 100,000,000						$ 75,000,000	$ 75,000,000								$ 85,700,000
Stock offering, commission rate								3.00%
Shelf Registration Statement [Member] | Maximum [Member] | Checkpoint [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement										$ 100,000,000
Shelf Registration Statement [Member] | Maximum [Member] | Checkpoint [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock offering, aggregate offering permitted by the agreement														$ 100,000,000
Stock offering, commission rate														3.00%

Stockholders' Equity (Stock B_2

Stockholders' Equity (Stock Based Compensation Plans of Partner Companies) (Details)	Dec. 31, 2020shares
2018 Long term Incentive Plan [Member] | Aevitas [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	1,602,000
2017 Long term Incentive Plan [Member] | Baergic [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	1,150,000
2017 Long term Incentive Plan [Member] | Cyprium [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	575,000
2017 Long term Incentive Plan [Member] | Oncogenuity [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	1,600,000
2017 Long term Incentive Plan [Member] | Tamid [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	1,600,000
2016 Long term Incentive Plan [Member] | Cellvation [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	300,000
2016 Long term Incentive Plan [Member] | Mustang [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	5,000,000
Shares available	1,180,085
2015 Long term Incentive Plan [Member] | Avenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	229,436
2015 Long term Incentive Plan [Member] | Checkpoint [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	9,000,000
Shares available	4,288,465
2015 Long term Incentive Plan [Member] | Helocyte [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	2,000,000
Shares available	341,667
2015 Long term Incentive Plan [Member] | Journey [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Authorized	3,642,857
Shares available	34,000

Stockholders' Equity (Stock-Bas

Stockholders' Equity (Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 13,451	$ 13,188
Avenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	710	1,839
Checkpoint [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,780	3,121
Mustang [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	2,987	2,664
Other Partners [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	190	252
Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	4,991	3,666
Executive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,504	1,428
Non-Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	159	121
Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 130	$ 97

Stockholders' Equity (Stock Opt

Stockholders' Equity (Stock Option Activities) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options vested and expected to vest, Number of shares	1,410,501	1,285,501
Number of shares, Granted		125,000
Number of shares, Exercised	(100,000)
Number of shares, Forfeited	(257,011)
Options vested and expected to vest, Number of shares	1,053,490	1,410,501	1,285,501
Options vested and expected to vest, Weighted average exercise price	$ 4.30	$ 3.75
Weighted average exercise price, Granted		1.18
Weighted average exercise price, Exercised	1.18
Weighted average exercise price, Forfeited	2.57
Options vested and expected to vest, Weighted average exercise price	$ 5.02	$ 4.30	$ 3.75
Total weighted average intrinsic value, Options vested and expected to vest	$ 684,752
Total weighted average intrinsic value, Granted		$ 173,750
Total weighted average intrinsic value, Options vested and expected to vest	$ 647,482	$ 684,752
Options vested and expected to vest, Weighted average contractual life	2 years 10 months 2 days	2 years 3 months 29 days	2 years 11 months 4 days

Stockholders' Equity (Restricte

Stockholders' Equity (Restricted Stock Awards and Restricted Stock Units) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted Stock Awards and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares, Unvested balance	15,507,504	13,768,014	12,645,982
Weighted average grant price, Unvested balance	$ 2.49	$ 2.46	$ 2.72
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted	1,873,072	1,546,408
Number of shares, Vested	(230,000)	(220,000)
Weighted average grant price, Granted	$ 2.57	$ 0.88
Weighted average grant price, Vested	$ 2.78	$ 3.16
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares Granted	630,126	290,000
Number of shares, Vested	(384,958)	(358,960)
Number of shares, Forfeited	(148,750)	(135,416)
Weighted average grant price, Granted	$ 3.82	$ 1.49
Weighted average grant price, Vested	3.49	3.61
Weighted average exercise price, Forfeited	$ 3.30	$ 3.91

Stockholders' Equity (Schedule

Stockholders' Equity (Schedule of Warrant activities) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Warrants outstanding, Number of shares	2,741,180	2,754,189
Warrants granted, Number of shares	1,849,450	60,000
Warrants forfeited, Number of shares	(9)	(73,009)
Warrants outstanding, Number of shares	4,590,621	2,741,180	2,754,189
Warrants exercisable, Number of shares	4,430,621
Warrants outstanding, Weighted average exercise price	$ 3.19	$ 3.28
Warrants granted, Weighted average exercise price	3.14	1.92
Warrants forfeited, Weighted average exercise price	3	5.65
Warrants outstanding, Weighted average exercise price	3.17	$ 3.19	$ 3.28
Warrants exercisable, Weighted average exercise price	$ 3.21
Warrants outstanding, Weighted average intrinsic value	$ 111,000	$ 0
Warrants granted, Weighted average intrinsic value	101,000	39,000
Warrants forfeited, Weighted average intrinsic value	2	0
Warrants outstanding, Weighted average intrinsic value	607,848	$ 111,000	$ 0
Warrants exercisable, Weighted average intrinsic value	$ 452,848
Warrants, Weighted average remaining contractual life	4 years 10 months 6 days	2 years 8 months 23 days	3 years 5 months 26 days
Warrants exercisable, Weighted average remaining contractual life	4 years 9 months 18 days

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details)

Oct. 27, 2017USD ($)ft²

Oct. 03, 2014USD ($)

Dec. 31, 2020USD ($)

Aug. 31, 2020USD ($)

Aug. 31, 2018USD ($)ft²

Oct. 27, 2017USD ($)

Jun. 30, 2017USD ($)ft²

Oct. 31, 2015USD ($)ft²

Dec. 31, 2020USD ($)

Dec. 31, 2019USD ($)

Nov. 01, 2019USD ($)

Oct. 30, 2015

Lessee, Operating Lease, Description [Abstract]

Operating lease term

15 years

Operating lease cost

$ 3,246,000

$ 3,199,000

Operating Lease, Expense

$ 2,500,000

2,000,000

2,100,000

Operating lease liabilities

$ 24,740,000

24,740,000

24,700,000

Operating lease right-of-use asset, net

$ 20,487,000

$ 20,487,000

$ 21,480,000

New York, NY Office Space [Member]

Lessee, Operating Lease, Description [Abstract]

Lease amount for office space

40,700,000

Lease expiration date

Apr. 30, 2031

New York, NY Office Space [Member] | TGTX and OPPM [Member]

Lessee, Operating Lease, Description [Abstract]

Lease amount for office space

16,000,000

New York, NY Office Space [Member] | OPPM [Member]

Lessee, Operating Lease, Description [Abstract]

Operating Lease, Expense

$ 300,000

Percentage of Rentable Area

10.00%

New York, NY Office Space [Member] | TGTX [Member]

Lessee, Operating Lease, Description [Abstract]

Operating Lease, Expense

$ 1,100,000

Percentage of Rentable Area

45.00%

Waltham office space [Member]

Lessee, Operating Lease, Description [Abstract]

Operating lease term

2 years

2 years

5 years

Operating lease, area leased | ft²

6,100

Operating Lease, Expense

$ 200,000

$ 200,000

Lease expiration date

Mar. 31, 2023

Journey [Member] | Scottsdale, Arizona [Member]

Lessee, Operating Lease, Description [Abstract]

Operating lease term

1 year

Operating lease, area leased | ft²

3,681

2,295

Operating Lease, Expense

$ 100,000

$ 94,000

$ 55,000

Lease expiration date

Dec. 31, 2022

Nov. 30, 2020

Mustang [Member] | Worcester, Massachusetts [Member]

Lessee, Operating Lease, Description [Abstract]

Operating lease, area leased | ft²

27,043

Operating Lease, Expense

$ 600,000

Lease amount for office space

3,600,000

Lease expiration date

Oct. 27, 2026

Security deposit

$ 800,000

800,000

$ 1,300,000

Mustang [Member] | Worcester, Massachusetts [Member] | Cash [Member]

Lessee, Operating Lease, Description [Abstract]

Security deposit

300,000

300,000

300,000

Mustang [Member] | Worcester, Massachusetts [Member] | Letter of Credit [Member]

Lessee, Operating Lease, Description [Abstract]

Security deposit

$ 500,000

$ 500,000

$ 1,000,000

Commitments and Contingencies_3

Commitments and Contingencies (Lease Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies
Operating lease cost	$ 3,246	$ 3,199
Shared lease costs	(1,873)	(1,876)
Variable lease cost	593	801
Total lease expense	$ 1,966	$ 2,124

Commitments and Contingencies_4

Commitments and Contingencies (Quantitative Information about Operating Leases) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies
Operating cash flows from operating leases	$ (2,958)	$ (3,001)
Right-of-use assets exchanged for new operating lease liabilities	$ 634
Weighted-average remaining lease term - operating leases (years)	5 years 8 months 12 days	6 years 3 months 18 days
Weighted-average discount rate - operating leases	6.30%	6.20%

Commitments and Contingencies_5

Commitments and Contingencies (Future Minimum Lease Payments) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
Year ended December 31, 2021	$ 3,353
Year ended December 31, 2022	3,461
Year ended December 31, 2023	3,233
Year ended December 31, 2024	3,193
Year ended December 31, 2025	3,244
Other	17,028
Total operating lease liabilities	33,512
Less: present value discount	(8,772)
Net operating lease liabilities, short-term and long-term	$ 24,740	$ 24,700

Employee Benefit Plan (Narrativ

Employee Benefit Plan (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan [Abstract]
Employee contribution percentage	4.00%
Employer matching contribution	$ 0.5	$ 0.4

Related Party Transactions (Nar

Related Party Transactions (Narrative) (Details) - USD ($)

Sep. 30, 2019

Sep. 14, 2019

Jul. 18, 2019

Mar. 12, 2018

Mar. 31, 2017

Mar. 17, 2017

Sep. 14, 2016

Oct. 03, 2014

Aug. 31, 2020

May 31, 2016

Sep. 30, 2014

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Jun. 12, 2020

Oct. 30, 2015

Related Party Transaction [Line Items]

Operating lease term

15 years

Revenue from TGTX

$ 1,068,000

$ 1,708,000

Interest paid

15,326,000

11,849,000

Total notes payable

$ 51,677,000

84,656,000

Checkpoint [Member]

Related Party Transaction [Line Items]

PIK dividend as a percentage of fully diluted outstanding capitalization

0.00%

Avenue [Member]

Related Party Transaction [Line Items]

Remaining funding commitment

$ 800,000

PIK dividend as a percentage of fully diluted outstanding capitalization

0.00%

Caelum [Member]

Related Party Transaction [Line Items]

PIK dividend as a percentage of fully diluted outstanding capitalization

0.00%

2018 Venture Notes [Member]

Related Party Transaction [Line Items]

Repayments of debt

$ 21,707,000

0

Interest paid

2,253,000

2,376,000

Interest Rate

8.00%

Proceeds from Notes

2,000,000

2017 Subordinated Note Financing [Member]

Related Party Transaction [Line Items]

Repayments of debt

$ 28,400,000

28,356,000

0

Interest paid

4,760,000

5,601,000

Total notes payable

0

28,400,000

Interest Rate

8.00%

Maximum borrowing capacity

$ 40,000,000

Opus Credit Facility (2019 Notes) [Member]

Related Party Transaction [Line Items]

Credit facility expiration date

Sep. 14, 2021

Sep. 14, 2019

Sep. 14, 2018

Repayments of debt

$ 21,700,000

9,000,000

Interest paid

710,000

1,449,000

Credit facility, amount outstanding

$ 0

9,000,000

Total notes payable

9,000,000

Interest Rate

12.00%

12.00%

Class of Warrant or Right, Exercise Price of Warrants or Rights

$ 3

Maximum borrowing capacity

$ 25,000,000

Promissory Note [Member] | 2018 Venture Notes [Member]

Related Party Transaction [Line Items]

Proceeds from Notes

$ 21,700,000

Maximum borrowing capacity

$ 21,700,000

Waltham office space [Member]

Related Party Transaction [Line Items]

Operating lease term

2 years

5 years

Total payment for rent

$ 300,000

200,000

DAK Capital Inc. [Member] | Opus Credit Facility (2019 Notes) [Member]

Related Party Transaction [Line Items]

Total notes payable

$ 3,800,000

Chief Executive Officer (Dr. Rosenwald) [Member]

Related Party Transaction [Line Items]

Interest own in percent by principal stockholder or director

9.90%

11.60%

Chief Executive Officer (Dr. Rosenwald) [Member] | Opus Credit Facility (2019 Notes) [Member]

Related Party Transaction [Line Items]

Repayments of debt

$ 500,000

Common shares issued (in shares)

396,825

Share price per share

$ 1.26

Total notes payable

$ 300,000

Executives Vice Chairman [Member]

Related Party Transaction [Line Items]

Interest own in percent by principal stockholder or director

10.80%

12.70%

Executives Vice Chairman [Member] | Opus Credit Facility (2019 Notes) [Member]

Related Party Transaction [Line Items]

Total notes payable

$ 2,000,000

Chief Executive Officer And Executive Vice President [Member] | Opus Credit Facility (2019 Notes) [Member]

Related Party Transaction [Line Items]

Interest paid

$ 500,000

Total notes payable

2,900,000

OPPM [Member] | New York, NY Office Space [Member]

Related Party Transaction [Line Items]

Percentage of Rentable Area

10.00%

TGTX [Member] | New York, NY Office Space [Member]

Related Party Transaction [Line Items]

Percentage of Rentable Area

45.00%

TGTX [Member] | Waltham office space [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

100,000

100,000

Shared Services Agreement [Member] | TGTX and OPPM [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

1,400,000

Shared Services Agreement [Member] | TGTX [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

600,000

500,000

Proceeds from Related Party Agreement

500,000

500,000

Desk Share Agreements [Member]

Related Party Transaction [Line Items]

Total payment for rent

2,900,000

2,800,000

Desk Share Agreements [Member] | New York, NY Office Space [Member]

Related Party Transaction [Line Items]

Total payment for rent

2,600,000

2,600,000

Desk Share Agreements [Member] | TGTX and OPPM [Member] | New York, NY Office Space [Member]

Related Party Transaction [Line Items]

Operating lease term

5 years

Related party transaction, receivables

400,000

Desk Share Agreements [Member] | OPPM [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

$ 0

Desk Share Agreements [Member] | OPPM [Member] | New York, NY Office Space [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

200,000

Percentage of Rentable Area

10.00%

20.00%

0.00%

Desk Share Agreements [Member] | TGTX [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

$ 1,700,000

Percentage of Rentable Area

65.00%

Desk Share Agreements [Member] | TGTX [Member] | New York, NY Office Space [Member]

Related Party Transaction [Line Items]

Related party transaction, receivables

$ 1,600,000

$ 1,300,000

Percentage of Rentable Area

45.00%

40.00%

Founders Agreement [Member]

Related Party Transaction [Line Items]

Agreement with partner companies, term

15 years

Agreement with partner companies, number of preferred stock received

250,000

Agreement with partner companies, percentage of preferred stock owned

100.00%

Agreement with partner companies, period for payment of equity fees

5 days

Agreement with partner companies, percentage of gross amount of any such equity or debt financing

2.50%

Agreement with partner companies, percentage of annual net assets payable as cash fee

4.50%

Agreement with partner companies, period for the payment of annual cash fee

90 days

Agreement with partner companies, change in control fee description

each such partner company will pay a one-time change in control fee equal to five (5x) times the product of (A) net sales for the twelve (12) months immediately preceding the change in control and (B) four and one-half percent (4.5%).

PIK dividend as a percentage of fully diluted outstanding capitalization

2.50%

Management Services Agreements [Member]

Related Party Transaction [Line Items]

Agreement with partner companies, term

5 years

National Securities Corporation ("NSC") [Member] | 2018 Venture Notes [Member]

Related Party Transaction [Line Items]

Warrant on Sale Price of Note Percentage

25.00%

National Securities Corporation ("NSC") [Member] | 2017 Subordinated Note Financing [Member]

Related Party Transaction [Line Items]

Repayments of debt

$ 28,400,000

Professional Fees

$ 2,800,000

Issuance of private placement, placement fees as a percentage of net proceeds

10.00%

10.00%

Warrants issued, percentage of aggregate principal amount of the Notes

10.00%

10.00%

National Securities Corporation ("NSC") [Member] | 2017 Subordinated Note Financing [Member] | Minimum [Member]

Related Party Transaction [Line Items]

Class of Warrant or Right, Exercise Price of Warrants or Rights

$ 3.61

National Securities Corporation ("NSC") [Member] | 2017 Subordinated Note Financing [Member] | Maximum [Member]

Related Party Transaction [Line Items]

Class of Warrant or Right, Exercise Price of Warrants or Rights

$ 4.75

InvaGen [Member] | Avenue [Member]

Related Party Transaction [Line Items]

Remaining funding commitment

$ 1,200,000

Credit facility, amount outstanding

$ 0

Interest Rate

7.00%

Maximum borrowing capacity

$ 2,000,000

Related Party Transactions (PIK

Related Party Transactions (PIK Dividend or Equity Fee Payable) (Details)	12 Months Ended
	Dec. 31, 2020
Helocyte [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 20, 2015
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%
Avenue [Member]
Related Party Transaction [Line Items]
Effective date	Feb. 17, 2015
PIK dividend as a percentage of fully diluted outstanding capitalization	0.00%
Mustang [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 13, 2015
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%
Checkpoint [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 17, 2015
PIK dividend as a percentage of fully diluted outstanding capitalization	0.00%
Annual equity fee as a percentage of fully diluted outstanding capitalization	2.50%
Cellvation [Member]
Related Party Transaction [Line Items]
Effective date	Oct. 31, 2016
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%
Caelum [Member]
Related Party Transaction [Line Items]
Effective date	Jan. 1, 2017
PIK dividend as a percentage of fully diluted outstanding capitalization	0.00%
Baergic [Member]
Related Party Transaction [Line Items]
Effective date	Dec. 17, 2019
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%
Cyprium [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 13, 2017
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%
Aevitas [Member]
Related Party Transaction [Line Items]
Effective date	Jul. 28, 2017
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%
Oncogenuity [Member]
Related Party Transaction [Line Items]
Effective date	Apr. 22, 2020
PIK dividend as a percentage of fully diluted outstanding capitalization	2.50%

Related Party Transactions (Sch

Related Party Transactions (Schedule of Equity Fees) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Dividends receivable	$ (13,061)	$ (7,589)
Dividends Current	$ 0	0
Aevitas [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 11	6
Caelum [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 0	0
Cellvation [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 7	7
Helocyte [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 138	131
Mustang [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 7,577	4,923
Checkpoint [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 4,617	2,510
Cyprium [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 711	5
Tamid [Member]
PIK Dividend date	January 1
Partner companies dividend	$ 0	$ 7

Related Party Transactions (Man

Related Party Transactions (Management Services Agreement) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Fortress - MSA Income	$ (4,000)	$ (4,000)
Consolidated (income) expense	$ 0	0
Helocyte [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 20, 2015
Partner companies, MSA fee expense	$ 500	500
Avenue [Member]
Related Party Transaction [Line Items]
Effective date	Feb. 17, 2015
Partner companies, MSA fee expense	$ 0	0
Mustang [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 13, 2015
Partner companies, MSA fee expense	$ 500	500
Checkpoint [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 17, 2015
Partner companies, MSA fee expense	$ 500	500
Cellvation [Member]
Related Party Transaction [Line Items]
Effective date	Oct. 31, 2016
Partner companies, MSA fee expense	$ 500	500
Baergic [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 9, 2017
Partner companies, MSA fee expense	$ 500	500
Cyprium [Member]
Related Party Transaction [Line Items]
Effective date	Mar. 13, 2017
Partner companies, MSA fee expense	$ 500	500
Aevitas [Member]
Related Party Transaction [Line Items]
Effective date	Jul. 28, 2017
Partner companies, MSA fee expense	$ 500	500
Tamid [Member]
Related Party Transaction [Line Items]
Effective date	Nov. 30, 2017
Partner companies, MSA fee expense	$ 0	500
Oncogenuity [Member]
Related Party Transaction [Line Items]
Effective date	Feb. 10, 2017
Partner companies, MSA fee expense	$ 500	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Line Items]
Income tax expense (benefit)	$ 136,000	$ 0
Effective income tax rate	0.13%	0.00%
Operating Loss Carryforwards, Valuation Allowance	$ 203,900,000
Minimum ownership interest in subsidiaries for consolidated income tax return	80.00%
Unrecognized tax benefits	$ 0
Unrecognized tax benefits, interest and penalties	0
Increase (decrease) in valuation allowance	$ 35,700,000
Income tax credits expiration date	Dec. 31, 2028
Caelum [Member]
Income Tax Disclosure [Line Items]
Income tax expense (benefit)		$ 0
Federal [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards without expiration	$ 284,800,000
Net operating losses (NOLs)	525,700,000
Income tax credits	$ 15,400,000
Net operating losses (NOLs), expiration	Dec. 31, 2026
State and Local Jurisdiction [Member]
Income Tax Disclosure [Line Items]
Operating loss carryforwards without expiration	$ 4,500,000
Net operating losses (NOLs)	648,200,000
Income tax credits	$ 1,200,000
Net operating losses (NOLs), expiration	Dec. 31, 2022

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense (Benefit)) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Current
Federal	$ 0	$ 0
State	136,000	0
Deferred
Federal	0	0
State	0	0
Total	$ 136,000	$ 0

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryforwards	$ 152,295	$ 125,657
Amortization of license fees	20,628	17,077
Amortization of in-process R&D	415	449
Stock compensation	14,732	13,280
Lease liability	7,306	7,454
Accruals and reserves	1,570	1,810
Tax credits	16,326	12,716
Startup costs	54	58
Unrealized gain/loss on investments	1,075	716
State taxes	41	0
Reserve on Sales Return, Discount and Bad Debt	1,455	0
Total deferred tax assets	215,897	179,217
Less: valuation allowance	(203,930)	(168,223)
Net deferred tax assets	11,967	10,994
Deferred tax liabilities:
Right of use asset	(6,050)	(6,280)
Fair Value adjustment on investment in Caelum	(4,804)	(2,879)
Basis in subsidiary	(1,113)	(1,835)
Total deferred tax assets, net	$ 0	$ 0

Income Taxes (Effective Income

Income Taxes (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Percentage of pre-tax income:
U.S. federal statutory income tax rate	21.00%	21.00%
State taxes, net of federal benefit	11.00%	12.00%
Credits	4.00%	3.00%
Non-deductible items	(1.00%)	0.00%
Provision to return	1.00%	1.00%
Stock based compensation shortfall	(1.00%)	(1.00%)
Change in state rate	0.00%	3.00%
Deconsolidation of Caelum	0	(3)
Change in valuation allowance	(35.00%)	(36.00%)
Change in subsidiary basis	1.00%	(1.00%)
Other	(1.00%)	1.00%
Effective income tax rate	0.13%	0.00%

Segment Information (Narrative)

Segment Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020segment
Segment Information
Number of reportable segment	2

Segment Information (Schedule o

Segment Information (Schedule of Segment Information) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net Revenue	$ 45,599,000	$ 36,629,000
Direct cost of goods	(14,594,000)	(10,532,000)
Sales and marketing costs	(17,384,000)	(17,120,000)
Research and development	(64,109,000)	(81,326,000)
General and administrative	(43,782,000)	(38,470,000)
Other income (expense)	(8,579,000)	9,159,000
Income tax expense	(136,000)	0
Net loss	(102,985,000)	(101,660,000)
Intangible asset, net	14,629,000	7,377,000	$ 1,417,000
Tangible assets	314,205,000	219,045,000
Total assets	328,834,000	226,422,000
Dermatology Products Sales [Member]
Segment Reporting Information [Line Items]
Net Revenue	44,531,000	34,921,000
Direct cost of goods	(14,594,000)	(10,532,000)
Sales and marketing costs	(17,384,000)	(17,120,000)
Research and development	0	0
General and administrative	(4,716,000)	(2,556,000)
Other income (expense)	(697,000)	0
Income tax expense	(96,000)
Net loss	7,044,000	4,713,000
Intangible asset, net	14,629,000	7,377,000
Tangible assets	30,843,000	19,946,000
Total assets	45,472,000	27,323,000
Pharmaceutical and Biotechnology Product Development [Member]
Segment Reporting Information [Line Items]
Net Revenue	1,068,000	1,708,000
Direct cost of goods	0	0
Sales and marketing costs	0	0
Research and development	(64,109,000)	(81,326,000)
General and administrative	(39,066,000)	(35,914,000)
Other income (expense)	(7,882,000)	9,159,000
Income tax expense	(40,000)
Net loss	(110,029,000)	(106,373,000)
Intangible asset, net	0	0
Tangible assets	283,362,000	199,099,000
Total assets	$ 283,362,000	$ 199,099,000

Revenues from Contracts and S_3

Revenues from Contracts and Significant Customers (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)product	Dec. 31, 2019USD ($)
Disaggregation of Revenue [Line Items]
Number of marketed products | product	5
Revenue from Contract with Customer, Including Assessed Tax	$ 44,531	$ 34,921
Product revenue constrained in prior period	$ 1,400	$ 0
Customer Concentration Risk [Member] | Accounts Receivable [Member]
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	12.00%
Customer one [Member] | Customer Concentration Risk [Member] | Revenue [Member]
Disaggregation of Revenue [Line Items]
Concentration risk, percentage		50.00%
Customer one [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Disaggregation of Revenue [Line Items]
Concentration risk, percentage		21.00%
Customer Two [Member] | Customer Concentration Risk [Member] | Revenue [Member]
Disaggregation of Revenue [Line Items]
Concentration risk, percentage		10.00%
Customer Two [Member] | Customer Concentration Risk [Member] | Accounts Receivable [Member]
Disaggregation of Revenue [Line Items]
Concentration risk, percentage		18.00%

Revenues from Contracts and S_4

Revenues from Contracts and Significant Customers (Company's product revenue) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues from Contracts and Significant Customers
Product revenue, net	$ 44,531	$ 34,921
Revenue - related party	1,068	1,708
Net revenue	$ 45,599	$ 36,629

Subsequent Events (Narrative) (

Subsequent Events (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Feb. 24, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Proceeds from issuance of preferred stock				$ 39,075	$ 6,038
Cyprium [Member]
Subsequent Event [Line Items]
Proceeds from issuance of preferred stock				$ 8,000
Subsequent Events [Member] | Sentynl Therapeutics, Inc [Member] | Cyprium [Member]
Subsequent Event [Line Items]
Total consideration		$ 9,000
Upfront fees payment		$ 8,000
Percentage of ownership over any FDA priority review voucher		100.00%
Subsequent Events [Member] | Sentynl Therapeutics, Inc [Member] | Cyprium [Member] | Clinical Development and Regulatory Milestones [Member]
Subsequent Event [Line Items]
Payments of milestones		$ 3,000
Subsequent Events [Member] | Sentynl Therapeutics, Inc [Member] | Cyprium [Member] | Achievement of Certain Sales Milestones [Member]
Subsequent Event [Line Items]
Payments of milestones		$ 255,000
Subsequent Events [Member] | 8% Cumulative Convertible Class A Preferred Stock [Member] | Journey [Member]
Subsequent Event [Line Items]
Preferred Stock, dividend rate percentage			8.00%
Common stock's average trading price discount percentage			7.50%
Proceeds from issuance of preferred stock	$ 12,500
Subsequent Events [Member] | 8% Cumulative Convertible Class A Preferred Stock [Member] | Journey [Member] | Minimum [Member]
Subsequent Event [Line Items]
Preferred stock offering, aggregate proceeds			$ 12,500
Number of common shares issuable as Preferred stock dividend			72,849
Subsequent Events [Member] | 8% Cumulative Convertible Class A Preferred Stock [Member] | Journey [Member] | Maximum [Member]
Subsequent Event [Line Items]
Preferred stock offering, aggregate proceeds			$ 30,000
Number of common shares issuable as Preferred stock dividend			174,838
Subsequent Events [Member] | 8% Cumulative Convertible Class A Preferred Stock [Member] | Journey [Member] | Preferred Stock has not been Converted into Journey Common Stock [Member] | Minimum [Member]
Subsequent Event [Line Items]
Preferred stock offering, aggregate proceeds			$ 25,000
Number of common shares issuable as Preferred stock dividend			3,400,000
Subsequent Events [Member] | 8% Cumulative Convertible Class A Preferred Stock [Member] | Journey [Member] | Preferred Stock has not been Converted into Journey Common Stock [Member] | Maximum [Member]
Subsequent Event [Line Items]
Number of common shares issuable as Preferred stock dividend			8,100,000