Alaunos Therapeutics (TCRT) 10-K 1 Mar 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 24, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Registrant Name	ZIOPHARM Oncology, Inc.
Entity Central Index Key	0001107421
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Trading Symbol	ZIOP
Document Transition Report	false
Document Annual Report	true
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock
Entity File Number	001-33038
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	One First Avenue
Entity Address, Address Line Two	Parris Building 34, Navy Yard Plaza
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02129
Entity Tax Identification Number	84-1475642
City Area Code	617
Local Phone Number	259-1970
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Common Stock, Shares Outstanding		214,667,023
Entity Public Float			$ 687,342,598

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 115,069	$ 79,741
Receivables	4,665	3,330
Prepaid expenses and other current assets	10,855	22,421
Total current assets	130,589	105,492
Property and equipment, net	10,231	1,110
Deposits	130	130
Right-of-use asset	4,650	2,272
Other non-current assets	745	110
Total assets	146,345	109,114
Current liabilities:
Accounts payable	960	906
Accrued expenses	16,589	10,846
Lease liability - current portion	819	774
Total current liabilities	18,368	12,526
Lease liability - noncurrent portion	3,995	1,578
Total liabilities	22,363	14,104
Commitments and contingencies (Note 9)
Stockholders' equity:
Common stock, $0.001 par value; 250,000,000 shares authorized; 214,591,906 and 181,803,320 shares issued and outstanding at December 31, 2020 and 2019, respectively	215	182
Additional paid-in capital	887,868	778,953
Accumulated deficit	(764,101)	(684,125)
Total stockholders' equity	123,982	95,010
Total liabilities and stockholders' equity	146,345	$ 109,114
Series 1 Preferred Stock
Current liabilities:
Series 1 preferred stock, $1,200 stated value; 250,000 designated; 0 shares issued and outstanding at December 31, 2020 and 2019; liquidation value of $0 million at December 31, 2020 and 2019

BALANCE SHEETS (Parenthetical)

BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	30,000,000	30,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	214,591,906	181,803,320
Common stock, shares outstanding	214,591,906	181,803,320
Series 1 Preferred Stock
Preferred stock, stated value	$ 1,200	$ 1,200
Preferred stock, shares authorized	250,000	250,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Preferred stock, liquidation preference	$ 0	$ 0

STATEMENTS OF OPERATIONS

STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Collaboration revenue			$ 146
Operating expenses:
Research and development	$ 52,696	$ 38,331	34,134
General and administrative	27,665	19,527	19,918
Total operating expenses	80,361	57,858	54,052
Loss from operations	(80,361)	(57,858)	(53,906)
Other income, net	385	813	631
Non-cash inducement warrant expense		(60,751)
Change in fair value of derivative liabilities	0	0	158
Net loss	(79,976)	(117,796)	(53,117)
Preferred stock dividends			(16,998)
Settlement of a related party relationship			207,361
Net income (loss) applicable to common stockholders	$ (79,976)	$ (117,796)	$ 137,246
Net income (loss) per share - basic	$ (0.38)	$ (0.70)	$ 0.96
Net income (loss) per share - diluted	$ (0.38)	$ (0.70)	$ 0.96
Weighted average common shares outstanding used to compute basic net income (loss) per share	209,636,456	167,952,114	143,508,674
Weighted average common shares outstanding used to compute diluted net income (loss) per share	209,636,456	167,952,114	143,710,160

STATEMENTS OF CHANGES IN PREFER

STATEMENTS OF CHANGES IN PREFERRED STOCK AND STOCKHOLDERS' Equity (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid In Capital	Accumulated Deficit	Series 1 Preferred Stock - Mezzanine
Balance at Dec. 31, 2017	$ (96,806)	$ 143	$ 615,493	$ (712,442)	$ 143,992
Balance (Accounting Standards Update 2014-09 [Member]) at Dec. 31, 2017	(8,131)			(8,131)
Balance (in shares) at Dec. 31, 2017		142,658,037			119,644
Stock-based compensation	7,534		7,534
Issuance of restricted common stock	1	$ 2	(1)
Issuance of restricted common stock (in shares)		150,321
Exercise of employee stock options	$ 242	$ 2	240
Exercise of employee stock options (in shares)	104,167	104,166
Cancelled restricted common stock	$ 1	$ (2)	3
Cancelled restricted common stock (in shares)		(271,433)
Repurchase of restricted common stock	(1,624)	$ (3)	(1,621)
Repurchase of restricted common stock (Shares)		(514,349)
Issuance of common stock in connection with a public offering, net	47,101	$ 19	47,082
Issuance of common stock in connection with a public offering, net (in shares)		18,939,394
Preferred stock dividends	(16,998)		(16,998)		$ (16,775)
Preferred stock dividends (in shares)					11,415
Settlement of a related party relationship (Note 7)	207,361			207,361	$ (160,767)
Settlement of a related party relationship (Note 7) (in shares)					(131,059)
Net loss	(53,117)			(53,117)
Balance at Dec. 31, 2018	85,564	$ 161	651,732	(566,329)
Balance (in shares) at Dec. 31, 2018		161,066,136
Stock-based compensation	6,341		6,341
Issuance of restricted common stock	1,000	$ 2	998
Issuance of restricted common stock (in shares)		1,519,766
Exercise of employee stock options	$ 1,219	$ 1,219
Exercise of employee stock options (in shares)	581,105	443,051
Cancelled restricted common stock (in shares)		(74,599)
Issuance of common stock upon exercise of warrants, net	$ 60,751		60,751
Repurchase of restricted common stock	(653)	$ (653)
Repurchase of restricted common stock (Shares)		(225,339)
Issuance of common stock in connection with at the market offering, net	6,085	$ 1	6,084
Issuance of common stock in connection with at the market offering, net (in shares)		1,271,274
Warrant exercise, net of commissions and expenses of $1.1 million	52,499	$ 18	52,481
Warrant exercise, net of commissions and expenses of $1.1 million (in shares)		17,803,031
Net loss	(117,796)			(117,796)
Balance at Dec. 31, 2019	95,010	$ 182	778,953	(684,125)
Balance (in shares) at Dec. 31, 2019		181,803,320
Stock-based compensation	6,829		6,829
Exercise of employee stock options	$ 442		442
Exercise of employee stock options (in shares)	338,333	252,799
Restricted stock awards		$ 1	(1)
Restricted stock awards (in shares)		805,900
Cancelled restricted common stock (in shares)		(194,897)
Issuance of common stock in connection with at the market offering, net	$ 13,016	$ 3	13,013
Issuance of common stock in connection with at the market offering, net (in shares)	2,814,673	2,814,673
Issuance of common stock in connection with a public offering, net	$ 88,661	$ 29	88,632
Issuance of common stock in connection with a public offering, net (in shares)		29,110,111
Net loss	(79,976)			(79,976)
Balance at Dec. 31, 2020	$ 123,982	$ 215	$ 887,868	$ (764,101)
Balance (in shares) at Dec. 31, 2020		214,591,906

STATEMENTS OF CHANGES IN PREF_2

STATEMENTS OF CHANGES IN PREFERRED STOCK AND STOCKHOLDERS' Equity (DEFICIT) (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Issuance of common stock, commissions and expenses			$ 2,898,000
Common stock issuance cost			$ 2,898,000
Market Offering [Member]
Issuance of common stock, commissions and expenses	$ 400,000	$ 100,000
Common stock issuance cost	400,000	100,000
Warrant [Member]
Issuance of common stock, commissions and expenses		1,100,000
Common stock issuance cost		$ 1,100,000
Public Offering [Member]
Issuance of common stock, commissions and expenses	5,900
Common stock issuance cost	$ 5,900

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net loss	$ (79,976)	$ (117,796)	$ (53,117)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,128	629	575
Stock-based compensation	6,829	7,341	7,534
Non-cash inducement warrant expense		60,751
Change in fair value of derivative liabilities	0	0	(158)
(Increase) decrease in:
Receivables	(1,335)	(1,466)	(1,845)
Prepaid expenses and other current assets	11,566	(1,729)	(1,263)
Right of use assets	(2,378)
Deposits		(2)
Other noncurrent assets	(635)	9,431	3,942
Increase (decrease) in:
Accounts payable	54	199	(3,709)
Accrued expenses	5,272	1,725	(1,145)
Deferred revenue			(146)
Deferred rent			(125)
Lease liabilities	2,462	63
Net cash used in operating activities	(57,013)	(40,854)	(49,457)
Cash flows from investing activities:
Purchases of property and equipment	(9,778)	(284)	(459)
Net cash used in investing activities	(9,778)	(284)	(459)
Cash flows from financing activities:
Proceeds from exercise of stock options	442	1,219	240
Repurchase of common stock		(653)	(1,622)
Proceeds from underwritten financing			47,101
Issuance of common stock upon exercise of warrants, net		52,499
Issuance of common stock in connection with a public offering, net	88,661
Issuance of common stock in connection with an at the market offering, net	13,016	6,085
Cash paid for settlement of related party relationship			(5,408)
Net cash provided by financing activities	102,119	59,150	40,311
Net decrease in cash and cash equivalents, and restricted cash	35,328	18,012	(9,605)
Cash and cash equivalents, and restricted cash, beginning of period	79,741	61,729	71,334
Cash and cash equivalents, and restricted cash, end of period	115,069	79,741	61,729
Supplementary disclosure of cash flow information:
Bonus paid in common stock		1,000
Fixed assets in accrued expenses	$ 471	$ 358
Supplementary disclosure of noncash investing and financing activities:
Noncash portion of related party relationship settlement			212,769
Series 1 Preferred Stock
Supplementary disclosure of noncash investing and financing activities:
Payment of dividends in preferred stock			$ 16,998

Organization

Organization	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Organization	1. Organization ZIOPHARM Oncology, Inc., which is referred to herein as “ZIOPHARM,” or the “Company,” is a biopharmaceutical company seeking to develop, acquire, and commercialize, on its own or with partners, a diverse portfolio of immuno-oncology therapies. The Company’s operations to date have consisted primarily of raising capital and conducting research and development. The Company’s fiscal year ends on December 31. The Company has operated at a loss since its inception in 2003 and has no recurring revenues from operations. The Company anticipates that losses will continue for the foreseeable future. As of December 31, 2020, the Company has approximately $115.1 million of cash and cash equivalents and the Company’s accumulated deficit was approximately $764.1 million. Given the Company’s current development plans, the Company anticipates its cash resources will be sufficient to fund its operations into the second quarter of 2022. The Company’s ability Our amended and restated certificate of incorporation authorizes us to issue 250,000,000 shares of common stock. As of February 24 In addition to these factors, our actual cash requirements may vary materially from our current expectations for a number of other factors that may include, but are not limited to, changes in the focus and direction of our development programs, competitive and technical advances, costs associated with the development of our product candidates, our ability to secure partnering arrangements, and the costs of filing, prosecuting, defending and enforcing our intellectual property rights. If we exhaust our capital reserves more quickly than anticipated, regardless of the reason, and we are unable to obtain additional financing on terms acceptable to us or at all, we will be unable to proceed with development of some or all of our product candidates on expected timelines and will be forced to prioritize among them. We expect that we will need additional financing to support our long-term plans for clinical trials and new product development. We expect to finance our cash needs through the sale of equity securities, strategic collaborations and/or debt financings, or through other sources that may be dilutive to existing stockholders. There can be no assurance that we will be able to obtain funding from any of these sources or, if obtained, what the terms of such funding(s) may be, or that any amount that we are able to obtain will be adequate to support our working capital requirements until we achieve profitable operations.

Financings

Financings	12 Months Ended
	Dec. 31, 2020
Text Block [Abstract]
Financings	2. Financings February 2020 Public Offering On February 5, 2020, the Company entered into an underwriting agreement with Jefferies, as representative of the several underwriters named therein, relating to the issuance and sale of 27,826,086 shares of its commo n stock. The price to the public in the offering was $ per share, and the underwriters agreed to purchase the from the Company pursuant to the underwriting agreement at a purchase price of $ per share. Under the terms of the underwriting agreement, the Company also granted the underwriters an option, exercisable for 30 days, to purchase up to an additional shares of common stock at a purchase price of $ per share. The offering was made pursuant to the Company’s Form S-3ASR 333-232283) On March 10, 2020 At-the-Market Offering Program During the year ended S-3ASR During the year ended December 31, 2019, the Company sold an aggregate of 1,271,274 shares of its common stock. The offering was made pursuant to the Company’s effective registration statement on Form S-3ASR November 2018 Private Placement and 2019 Inducement Warrants On November 11, 2018, the Company entered into a securities purchase agreement with certain institutional and accredited investors pursuant to which it sold an aggregate of 18,939,394 immediately separable units at a price per unit of $2.64 to such investors, for net proceeds of approximately $47.1 million. Each unit was comprised of (i) one share of the Company’s common stock, par value $0.001 per share and (ii) a warrant to purchase one share of common stock. The securities issued by the Company pursuant to the securities purchase agreement and to be issued upon exercise of the warrants were not registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. When issuing the units, the Company relied on the private placement exemption from registration provided by Section 4(a)(2) of the Securities Act and by Rule 506 of Registration D, promulgated thereunder and on similar exemptions under applicable state laws and filed a Form D with the SEC on November 19, 2018. On February 7, 2019, the Company filed a registration statement on Form S-3 warrants. July 2019 and September 2019 Warrant Exercise On July 26, 2019 and September 12, 2019, the Company entered into agreements for the exercise of the warrants issued in November 2018 to purchase common stock in a private placement. Pursuant to the terms of the a exercised warrants for an aggregate of shares of common stock, at an exercise price of $ per share. The Company issued new warrants to purchase up to additional shares of common stock as an inducement for warrant holders to exercise their 2018 warrants early. The new warrants will become exercisable six months following the date of issuance, will expire on the fifth anniversary of the initial exercise date, and have an exercise price of $ (Note 10). Proceeds from the exercise of the warrants, before deducting placement agent fees and other related expenses of $ million were approximately $ million. For the year ended December 31, 2019, the Company also recorded $ million in non-cash inducement warrant expense, which is included in the Company’s statement of operations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America or U.S. GAAP. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. The Company’s most significant estimates and judgments used in the preparation of the financial statements are: • Clinical trial expenses and other research and development expenses; • Collaboration agreements; • Fair value measurements of stock-based compensation and; and • Income taxes. Impact of COVID-19 Pandemic With the ongoing COVID-19 COVID-19 COVID-19 healthcare systems and the other risks and uncertainties associated with the COVID-19 Subsequent Events The Company evaluated all events and transactions that occurred after the balance sheet date through the date of the Annual Report. Except as disclosed below, the Company did not have any material subsequent events that impacted its financial statements or disclosures. On February 4, 2021, the Company entered into an agreement with Watermill Asset Management Corp. and Robert W. Postma. Pursuant to the Settlement Agreement, the Company increased the size of the Company’s Board of Directors from eight to nine directors and appointed Mr. Postma to fill the newly created directorship. Mr. Postma will serve an initial term expiring at the Company’s 2021 annual meeting of stockholders. Additionally, the Company agreed to nominate each of Mr. Postma, Jaime Vieser and Holger Weis for election at any stockholder meeting at which directors are to be elected and will recommend, support, and solicit proxies for the election of each of Messrs. Postma, Vieser and Weis. Additionally, the Company agreed to reimburse Watermill for up to thousand of its reasonable out-of-pocket fees and expenses. This agreement also resulted in $1.0 million in strategic advisory services becoming due. These costs were expensed during the year ended Organizational Changes During the year ended December 31, 2020 there were changes in the members of the Board of Directors. The following Directors left during the quarter: Scott Braunstein on November 16, 2020, Elan Ezickson on December 3, 2020, and Scott Tarriff on December 15, 2020. Messers. Braunstein and Ezickson received an extended period to exercise stock options along accelerated vesting of restricted stock. In turn, the following Directors joined the board: Mary Thistle on November 15, 2020, Jaime Vieser on December 15, 2020, and Holger Weis on December 15, 2020. On December 10, 2020, Satyavrat Shukla notified the Company of his decision to resign from the position of Chief Financial Officer of the Company, effective December 31, 2020. Included in his separation agreement, Mr. Shukla was to receive his annual bonus which was accrued at December 31, 2020. Additionally, on February 25, 2021, the Company announced that Heidi Hagen, formerly Lead Independent Director, was appointed Interim Chief Executive Officer, replacing Dr. Laurence Cooper, MD., Ph.D. Ms. Hagen is remaining a member of the Board of Directors. Dr. Cooper is also stepping down from his seat on the Board of Directors and is expected to continue with the Company in a scientific advisory capacity to support the Company’s R&D programs. Cash and Cash Equivalents Cash equivalents consist primarily of demand deposit accounts, certificates of deposit and deposits in short-term U.S. treasury money market mutual funds. Cash equivalents are stated at cost, which approximates fair market value. Concentrations of Credit Risk Financial instruments which potentially subject the Company to concentrations of credit risk consist Property and Equipment Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Expenditures for maintenance and repairs are charged to expense while the costs of significant improvements are capitalized. Depreciation and amortization is calculated on a straight-line basis using the following periods, which represent the estimated useful lives of the assets: ● Office and computer equipment 3 years ● Software 3 years ● Laboratory equipment 5 years ● Leasehold improvements Life of the lease Costs, including certain design, construction and installation costs related to assets that are under construction and are in the process of being readied for their intended use, are recorded as construction in progress and are not depreciated until such time as the subject asset is placed in service. Repairs and maintenance that do not extend the useful life of the asset are expensed as incurred. Upon sale, retirement Long-Lived Assets Assessments of long-lived assets and the remaining useful lives of such long-lived assets are reviewed for impairment whenever a triggering event occurs or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. An asset, or group of assets, are considered to be impaired when the undiscounted estimated net cash flows expected to be generated by the asset, or group of assets, are less than its carrying amount. The impairment recognized is the amount by which the carrying amount exceeds the fair market value of the impaired asset, or group of assets, based on the present value of the expected future cash flows associated with the use of the asset. Operating Segments Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, the Company’s chief operating decision maker, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment and does not track expenses on a program-by-program Warrants The Company assesses whether warrants issued require accounting as derivatives. The Company determined that the warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 815, Derivatives and Hedging The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value on a recurring basis as of December 31, 2020 and 2019 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 75,990 $ 75,990 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 68,031 $ 68,031 $ — $ — The cash equivalents represent demand deposit accounts and deposits in a short-term United States treasury money market mutual fund quoted in an active market and classified as a Level 1 asset. Revenue Recognition from Collaboration Agreements The Company adopted Accounting Standards Codification, or ASC Topic 606, Revenue from Contracts with Customers, its assessment and the implementation resulted in a cumulative effect adjustment to accumulated deficit as of January 1, 2018 of approximately $8.1 million and a corresponding increase to the contract liability (formerly deferred revenue). The adjustment to the Company’s financial statements due to the adoption of ASC 606 is related to the Company’s Ares Trading Agreement (Note 6), which was the Company’s sole open revenue contract outstanding at January 1, 2018. There was no revenue for the years ended December 31, 2020 and 2019. The Company primarily generates revenue through collaboration arrangements with strategic partners for the development and commercialization of product candidates. Commencing January 1, 2018, the Company recognized revenue in accordance with ASC 606 which replaced ASC 605, Multiple Element Arrangements The Company recognizes collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property, research and development services and options to purchase additional goods and/or services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front non-refundable, up-front The terms of the Company’s arrangements with customers typically include the payment of one or more of the following: (i) non-refundable, up-front catch-up payments based upon the achievement of a certain level of product sales, the Company recognizes revenue upon the later of: (i) when the related sales occur or (ii) when the performance obligation to which some or all of the payment has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any development, regulatory or commercial milestones or royalty revenue resulting from any of its collaboration arrangements. Consideration that would be received for optional goods and/or services is excluded from the transaction price at contract inception. The Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. However, certain components of variable consideration are allocated specifically to one or more particular performance obligations in a contact to the extent both of the following criteria are met: (i) the terms of the payment relate specifically to the efforts to satisfy the performance obligation or transfer the distinct good or service and (ii) allocating the variable amount of consideration entirely to the performance obligation or the distinct good or service is consistent with the allocation objective of the standard whereby the amount allocated depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services. The Company develops assumptions that require judgment to determine the standalone selling price for each performance obligation identified in each contract. The key assumptions utilized in determining the standalone selling price for each performance obligation may include forecasted revenues, development timelines, estimated research and development costs, discount rates, likelihood of exercise and probabilities of technical and regulatory success. Revenue is recognized based on the amount of the transaction price that is allocated to each respective performance obligation when or as the performance obligation is satisfied by transferring a promised good and/or service to the customer. For performance obligations that are satisfied over time, the Company recognizes revenue by measuring the progress toward complete satisfaction of the performance obligation using a single method of measuring progress which depicts the performance in transferring control of the associated goods and/or services to the customer. The Company uses input methods to measure the progress toward the complete satisfaction of performance obligations satisfied over time. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up The Company recognized the upfront payment received in 2015 associated with a former open contract as a contract liability upon receipt of payment as it requires deferral of revenue recognition to a future period until the Company performs its obligations under the arrangement. Amounts expected to be recognized as revenue within the twelve months following the balance sheet date were classified in current liabilities. Amounts not expected to be recognized as revenue within the twelve months following the balance sheet date were classified as contract liabilities, net of current portion. The Company determined that there were three performance obligations; the first performance obligation consists of the license and research development services and the other two performance obligations are material rights as it relates to potential future targets that have not yet been identified. As described above, the transaction price of $57.5 million was allocated to the performance obligations based on their relative standalone selling prices. There were multiple distinct performance obligations, including material rights; thus, the Company allocated the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost-plus margin. Revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations using an input measure. Furthermore, the Company has not capitalized any contract costs under the guidance in ASC 340-40, Other Assets and Deferred Costs: Contracts with Customers The Company did not believe that any variable consideration should be included in the transaction price at the date of adoption of ASC 606 on January 1, 2018. Such assessment considered the application of the constraint to ensure that estimates of variable consideration would be included in the transaction price only to the extent the Company had a high degree of confidence that revenue would not be reversed in a subsequent reporting period. The Company will re-evaluate the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as other changes in circumstances Impact of Topic 606 Adoption As a result of adopting ASC 606, the Company recorded an $8.1 million adjustment to the opening balance of accumulated deficit in the first quarter of 2018 as a result of the treatment of the up-front d 2015 605-25 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Contract liability, current portion $ 622 $ (5,767 ) $ 6,389 Contract liability, net of current portion $ 49,037 $ 13,898 $ 35,139 Accumulated deficit $ (720,573 ) $ (8,131 ) $ (712,442 ) ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Collaboration revenue $ 146 $ (4,732 ) $ 4,878 Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Net income (loss) applicable to common shareholders $ 137,246 $ (4,732 ) $ 141,978 Net income (loss) per share - basic $ 0.96 $ (0.03 ) $ 0.99 Net income (loss) per share - diluted $ 0.96 $ (0.03 ) $ 0.99 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Net loss $ (53,117 ) $ (4,732 ) $ (48,385) Changes in contract liability $ — $ — $ — The most significant change above relates to the Company’s collaboration revenue, which to date has been exclusively generated from its collaboration arrangement with Ares Trading and PGEN Therapeutics, a wholly owned subsidiary of Precigen Inc., or Precigen, which was formerly known as Intrexon Corporation, ( Note 7 the research and development services which was estimated to be 9 years. In connection , the Company uses cost-based input method to measure were generally consistent with the units of account identified under ASC 605 , the timing of the allocation of the transaction price to the identified performance obligations under ASC 606 differed from the allocations of consideration under ASC 605 . Accordingly, the transaction price ultimately allocated to each performance obligation under ASC 606 differed from the amounts allocated under ASC 605 . Additionally, at December 31 , 2018 , the contract liability is $0 under both methods of revenue recognition (Note 7) . There is no revenue related to the years ended December 31 , 2020 and 2019 . Research and Development Costs As part of the process of preparing our financial statements estimate • CROs in connection with performing research services on our behalf and clinical trials, • investigative sites or other providers in connection with clinical trials, • vendors in connection with preclinical and clinical development activities, and • vendors related to product manufacturing, development, and distribution of preclinical and clinical supplies. We base our expenses related to preclinical studies and clinical trials on our estimates of the services received and efforts expended pursuant to quotes and contracts with multiple CROs that conduct and manage clinical trials on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the clinical expense. Payments under some of these contracts depend on factors such as the completion of clinical trial milestones. In accruing service fees, we estimate the time period over which services will be performed, enrollment of patients, number of sites activated and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrual or amount of prepaid expense accordingly. Although we do not expect our estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in us reporting amounts that are too high or too low in any particular period. To date, we have not made any material adjustments to our prior estimates of accrued research and development expenses. Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled. The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a “more-likely-than-not” Accounting for Stock-Based Compensation Stock-based compensation cost is measured at the grant date, based on the estimated fair value of the award, and is recognized as expense over the employee’s requisite service period. Stock-based compensation expense is based on the number of awards ultimately expected to vest and is therefore reduced for an estimate of the awards that are expected to be forfeited prior to vesting. Consistent with prior years, the Company uses the Black-Scholes option pricing model which requires estimates of the expected term option holders will retain their options before exercising them and the estimated volatility of the Company’s common stock price over the expected term. The Company recognizes the full impact of its share-based employee payment plans in the statements of operations for each of the years ended December 31, 2020, 2019, and 2018 and did not capitalize any such costs on the balance sheets. The Company recognized $4.3 million, $4.0 million, and $3.0 million of compensation expense related to stock options during the years ended December 31, 2020, 2019, and 2018, respectively. In the years ended December 31, 2020, 2019, and 2018, the Company recognized $2.5 million, $2.3 million, and $4.5 million of compensation expense, respectively, related to restricted stock (Note 14). The total compensation expense relating to vesting of stock options and restricted stock awards for the years ended December 31, 2020, 2019, and 2018 was $6.8 million, $6.3 million, and $7.5 million, respectively.The following table presents share-based compensation expense included in the Company’s Statements of Operations: Year ended December 31, (in thousands) 2020 2019 2018 Research and development $ 2,098 $ 1,461 $ 1,683 General and administrative 4,731 4,880 5,851 Share based employee compensation expense before tax 6,829 6,341 7,534 Income tax benefit — — — Net share based employee compensation expense $ 6,829 $ 6,341 $ 7,534 The fair value of each stock option is estimated at the date of grant using the Black-Scholes option pricing model. The estimated weighted-average fair value of stock options granted to employees in 2020, 2019, and 2018 was approximately volatility, expected . 107 and No . 110 as it continues to meet the requirements promulgated in SAB No . 110 . The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below: 2020 2019 2018 Weighted average risk-free interest rate 0.36 - 1.68% 1.39 - 2.53% 2.55 - 3.06% Expected life in years 5.75 - 6.25 5.75 - 6.25 6 Expected volatility 71.11 - 74.41% 71.39 - 85.00% 80.75 - 84.71% Expected dividend yield 0 0 0 Net Income (Loss) Per Share Basic net loss per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. For the Year Ended December 31, in thousands, except share and per share data 2020 2019 2018 Basic Net loss $ (79,976 ) $ (117,796 ) $ (53,117 ) Preferred stock dividends — — (16,998 ) Settlement of a related party relationship — — 207,361 Net income / (loss) applicable to common shareholders $ (79,976 ) $ (117,796 ) $ 137,246 Weighted-average common shares outstanding 209,636,456 167,952,114 143,508,674 Earnings per share, basic $ (0.38 ) $ (0.70 ) $ 0.96 Diluted Net Loss $ (79,976 ) $ (117,796 ) $ (53,117 ) Preferred stock dividends — — (16,998 ) Precigen license transaction — — 207,361 Net income / (loss) applicable to common shareholders $ (79,976 ) $ (117,796 ) $ 137,246 Weighted-average common shares outstanding 209,636,456 167,952,114 143,508,674 For the Year Ended December 31, in thousands, except share and per share data 2020 2019 2018 Effect of dilutive securities Stock options — — 201,362 Unvested restricted common stock — — 124 Warrants — — — Dilutive potential common shares — — 201,486 Shares used in calculating diluted earnings per share 209,636,456 167,952,114 143,710,160 Earnings per share, diluted $ (0.38 ) $ (0.70 ) $ 0.96 Certain shares related to some of the Company’s outstanding common stock options, unvested restricted stock, preferred stock, and warrants have not been included in the computation of diluted net earnings (loss) per share for the years ended December , , and as the result would be , , , and consist of the following: December 31, 2020 2019 2018 Stock options 6,832,386 6,872,879 5,075,723 Inducement stock options 588,333 1,030,000 500,000 Unvested restricted stock 786,280 939,636 681,946 Warrants 22,272,727 22,272,727 18,939,394 30,479,726 31,115,242 25,197,063 During the year ended December 31, 2018, the Company and PGEN entered into a License Agreement to replace all existing agreements between the companies that provides the Company with certain exclusive and non-exclusive New Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes 2019-12

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment, net	4. Property and Equipment, net Property and equipment, net, consists of the following: December 31, (in thousands) 2020 2019 Office and computer equipment $ 869 $ 1,436 Software 1,153 1,030 Leasehold improvements 7,457 1,195 Research and development equipment 5,401 1,892 Construction - in-process 313 389 15,193 5,942 Less: accumulated depreciation (4,962 ) (4,832 ) Property and equipment, net $ 10,231 $ 1,110 Depreciation expense charged to the statement of operations for the years ended December 31, 2020, 2019, and 2018 was $1.1 million, $629 thousand, and $575 thousand, respectively ( ote 3)

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consist of the following: December 31, (in thousands) 2020 2019 Clinical services $ 4,450 $ 5,247 Employee compensation 3,298 1,910 Preclinical services 749 1,147 Professional services 3,993 991 Manufacturing services 3,159 586 Accrued vacation 725 489 Payroll taxes and benefits 16 284 Other consulting services 199 192 Total $ 16,589 $ 10,846

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	6. Related Party Transactions Collaborations with Precigen During the year ended December 31, 2018 Company Agreement During the year ended December 31, 2018, the Company issued an aggregate of 11,415 shares of Series 1 preferred stock to Precigen, the holder of all of the outstanding shares of the Company’s Series 1 preferred stock, as monthly dividend payments. The Company recorded such shares of Series 1 preferred stock at a fair value of $18.9 million, which is a component of temporary equity and recorded a loss on the change of the derivative liabilities in the amount of $1.3 million. The Series 1 preferred stock was cancelled on October 5, 2018. See Notes 3 and 13 for additional discussion regarding the accounting for and valuation of these derivative financial instruments. During the years ended December 31, 2020, 2019, and 2018, the Company recorded expenses of $0.1 million, $3.0 million, and $8.1 million, respectively, for services performed by Precigen. As of December 31, 2019, the Company recorded $0.1 million in current liabilities on its balance sheet for amounts due to Precigen. Collaboration with PGEN and MD Anderson On January 13, 2015, the Company, together with Precigen, entered into the MD Anderson License with MD Anderson (which Precigen subsequently assigned to PGEN). Pursuant to the MD Anderson License, the company, together with PGEN, hold an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell non-viral to February 2021 and was formerly a tenured professor of pediatrics at MD Anderson. In partial consideration for entering into the MD Anderson License, the Company issued MD Anderson an aggregate of During the years ending December 31, 2020, 2019, and 2018, the Company did not make any payments to MD Anderson, and the total aggregate payments made in connection with this agreement are $41.9 million. The net balance of cash resources on hand at MD Anderson available to offset expenses and future costs is $8.1 million, which is included in prepaid expenses and other current assets. The classification is based on management’s current estimate of plans to utilize the prepaid balance and is subject to revision on a quarterly basis. Collaboration with Vineti Inc. On July 9, 2020, the Company entered into a master service agreement and statement of work with Vineti, Inc., or Vineti. Pursuant to the agreements, Vineti is developing a software platform to coordinate and orchestrate the order, cell collection and manufacturing process for the Company’s TCR-T clinical programs. Heidi Hagen, who became a director of the Company in June 2019 and our Interim Chief Executive Officer on February 25, 2021, is a co-founder and former officer, of Vineti. In the year ended December 31, 2020, the Company recorded expenses of approximately $29 thousand for services performed by Vineti. Joint Venture with TriArm Therapeutics/Eden Biocell On December 19, 2018, the Company and TriArm launched Eden BioCell as a joint venture to lead commercialization of the Company’s Sleeping Beauty-generated CAR-T therapies in the People’s Republic of China (including Macau and Hong Kong), Taiwan and Korea. The Company licensed to Eden BioCell the rights in Greater China for its third-generation Sleeping Beauty-generated CAR-T therapies targeting the CD19 antigen. Eden BioCell is owned equally by the Company and TriArm and the parties share decision-making authority. TriArm has contributed $10.0 million to Eden BioCell and has committed up to an additional $25.0 million to this joint venture. TriArm also manages all clinical development in the territory pursuant to a Master Services Agreement between TriArm and Eden BioCell. James Huang, who became a director of the Company in July 2020, Chairman of the Board of Directors in January 2021 and Executive Chairman in February 2021, was the founder and serves as managing partner of Panacea Venture, which is an investor in TriArm. Mr. Huang also serves as a member of Eden BioCell’s Board of Directors.

Settlement of a Related Party R

Settlement of a Related Party Relationship	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Settlement of relatedparty relationship	7. Settlement of a Related Party Relationship Exclusive License Agreement with PGEN Therapeutics On October 5, 2018, the Company entered into the license agreement with PGEN. As between the Company and PGEN, the terms of the License Agreement replace and supersede the terms of: (a) that certain Exclusive Channel Partner Agreement by and between the Company and Precigen, dated January 6, 2011, as amended by the First Amendment to Exclusive Channel Partner Agreement effective September 13, 2011, the Second Amendment to the Exclusive Channel Partner Agreement effective March 27, 2015 2015 2015 Pursuant to the terms of the License Agreement, PGEN has granted the Company exclusive, worldwide rights to research, develop and commercialize (i) products utilizing PGEN’s RheoSwitch ® ® IL-12 (iii) T-cell sub-licensable Sleeping Beauty The Company is solely responsible for all aspects of the research, development and commercialization of the exclusively licensed products for the treatment of cancer. The Company is required to use commercially reasonable efforts to develop and commercialize IL-12 two-year In consideration of the licenses and other rights granted by PGEN, the Company pays PGEN an annual license fee of $ million. The Company recorded a liability for $0.1 million for the years ended December 31, 2019, and has included this amount in accrued expenses on the balance sheet. The Company will also make milestone payments totaling up to an additional $52.5 million for each exclusively licensed program upon the initiation of later stage clinical trials and upon the approval of exclusively licensed products in various jurisdictions. In addition, the Company will pay PGEN tiered royalties ranging from low-single IL-12 low-single mid-single The Company is responsible for all development costs associated with each of the licensed products . PGEN will pay the Company royalties ranging from low-single mid-single During the years ended December 31, 2020, 2019 and 2018, there were no expenses for services performed by PGEN. As of December 31, 2020 and 2019, the Company had $0.1 million in accrued expenses for amounts due to PGEN. In consideration of the Company The Company determined that this transaction represented a capital transaction between related parties. The Company fair valued the preferred stock and the derivative liability on the date of the transaction, noting a total fair value of $163.3 million. The relinquishment of the Ziopharm’s obligation under the Ares Trading Agreement was also considered part of the overall capital transaction. The Company recognized an additional credit to accumulated deficit of $49.5 million as a result of the relief of the obligation under the Ares Trading Agreement (Note 7). The total amount of the settlement was $212.8 million. The Company incurred approximately $7.4 million of transaction advisory costs with third-party vendors, of which $5.4 million was considered a direct cost associated with the Series 1 preferred stock extinguishment and is also included as part of the consideration transferred. The remaining $2.0 million of transaction costs were recognized as an expense during the year ended December 31, 2018. The Company recognized a net credit to accumulated deficit of $207.3 million, calculated as the difference in the carrying value of the Series 1 preferred stock, derivative liability, and contract liability, and the consideration transferred of $5.4 million, in connection with the transaction. This amount is included in net income available to common shareholders in the calculation of earnings per share for the year ended December 31, 2018 (Note 3).

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases, Operating [Abstract]
Leases	8. Leases Operating Leases The Company adopted FASB ASU No. 2016-02, Leases (Topic 842) expedients permitted under the transition guidance within Topic 842 which, among other things, allowed it to carry forward the historical lease classification. The Company does not allocate consideration in its leases to lease and non-lease The Company uses its estimated incremental borrowing rate, which is derived from information available at the lease commencement date, in determining the present value of lease payments. The Company’s incremental borrowing rate represents the rate of interest that it would have to pay to borrow over a similar term an amount equal to the lease payments in a similar economic environment. The Company considers publicly available data for instruments with similar terms and characteristics when determining its incremental borrowing rates. The adoption of Topic 842 resulted in recognition of approximately $1.6 million of right-of-use right-of-use In June 2012, the Company entered into a master lease for the Company’s corporate office headquarters in Boston, which was originally set to expire in August 2016, but renewed through August 31, 2021. As of December 31, 20 20 9 two hundred and ten On March 12, 2019, the Company entered into a lease agreement for office space in Houston. Under the terms of the First Houston Lease agreement, the Company leases approximately 1,038 8,443 % throughout the term. Effective April 13, 2020, the Company leased an additional 5,584 thousand per month through February 2027, subject to an annual base rent increase of approximately % throughout the term. All future rent expense incurred in Houston, will be deducted from the Company’s prepayments at MD Anderson. Effective June 1, 2020, the Company entered into a noncancelable lease for a period of less than a year with monthly payments of approximately $ thousand. Effective September 1, 2020, the Company added additional space to the noncancelable lease for a period of less than a year with monthly payments now totaling approximately $ thousand. Effective December 15, 2020, the Company leased approximately 35,482 square feet from MD Anderson. The Company is initially required to make rental payments of approximately $ thousand per month through April 2028, subject to an annual base rent increase of approximately % throughout the term beginning in April 202 3 The components of lease expense were as follows: Years Ended December 31, 2020 2019 Operating lease cost $ 1,054 $ 772 Total lease cost $ 1,054 $ 772 Weighted-average remaining lease term (years) 6.19 4.42 Weighted-average discount rate 8.00 % 8.00 % Cash paid for amounts included in the measurement of the lease liabilities were $1.0 million for the year-ended December 31, 2020. The Company recognized new operating lease assets obtained in exchange for operating for As of December 31, 2020, the maturities of the Company’s operating lease liabilities Maturity of Lease Liabilities Operating Leases 2021 $ 1,189 2022 800 2023 820 2024 844 2025 869 Thereafter 1,650 Total lease payments $ 6,172 Less : imputed interest and adjustments (1,358 ) Present value of lease payments $ 4,814

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies License Agreements Exclusive License Agreement with PGEN On October 5, 2018, the Company entered into an exclusive license agreement with PGEN. Refer to Note 7 – Settlement of a Related Party Relationship License Agreement and Research and Development Agreements —The University of Texas MD Anderson Cancer Center On January 13, 2015, ZIOPHARM, together with Precigen, entered into the MD Anderson License with MD Anderson (which Precigen subsequently assigned to PGEN). Pursuant to the MD Anderson License, the Company, together with PGEN, holds an exclusive, worldwide license to certain technologies owned and licensed by MD Anderson including technologies relating to novel CAR T-cell non-viral May 2015 to February 2021 and was formerly a tenured professor of pediatrics at MD Anderson. The term of the MD Anderson License expires on the later of (a) the expiration of all patents licensed thereunder, or (b) the twentieth anniversary of the date of the MD Anderson License; provided, however, that following the expiration of the term of the MD Anderson License, the Company, together with PGEN, shall have a fully-paid up, royalty free, perpetual, irrevocable and sublicensable license to use the licensed intellectual property thereunder. After ten years from the date of the MD Anderson License and subject to a 90-day non-exclusive case-by-case 180-day cured within 60 days of receiving such notice. In addition, the MD Anderson License will terminate upon the occurrence of certain insolvency events for both the Company and PGEN and may be terminated by the mutual written agreement of the Company, PGEN, and MD Anderson. On August 17, 2015, the Company, PGEN and MD Anderson entered into the Research and Development, or the 2015 Agreement, to formalize the scope and process for the transfer by MD Anderson, pursuant to the terms of the MD Anderson License, of certain existing research programs and related technology rights, as well as the terms and conditions for future collaborative research and development of new and ongoing research programs. Pursuant to the 2015 Agreement, the Company, PGEN and MD Anderson have agreed to form a joint steering committee that will oversee and manage the new and ongoing research programs. Under the License Agreement with PGEN, ZIOPHARM and PGEN agreed that PGEN would no longer participate on the joint steering committee after the date of the License Agreement. As provided under the MD Anderson License, the Company provided funding for research and development activities in support of the research programs under the Research and Development Agreement for a period of three years and in an amount of no less than $15.0 million and no greater than $20.0 million per year. On October 22, 2019, the Company entered into an amendment to the Research and Development Agreement extending its term until December 31, 2026. On October 22, 2019, the Company entered into the 2019 Research and Development Agreement, or the 2019 Agreement, with MD Anderson, pursuant to which the parties agreed to collaborate with respect to the Company’s Sleeping Beauty non-viral The Company will own all intellectual property developed under the 2019 Agreement and will retain all rights to intellectual property for oncology products manufactured using non-viral Sleeping Beauty non-exclusive In connection with the execution of the 2019 Agreement, the Company issued MD Anderson a warrant to purchase 3,333,333 shares of common stock. Refer to Note 10 – Warrants The Company has agreed, beginning on January 1, 2021, to reimburse MD Anderson up to a total of $20.0 million for development costs incurred starting after January 1, 2021 under the 2019 Agreement. In addition, the Company will pay MD Anderson royalties on net sales of its TCR products at rates in the low single digits. The Company is required to make performance-based payments upon the successful completion of clinical and regulatory benchmarks relating to its TCR products. The aggregate potential benchmark payments are $ million, of which only $ million will be due prior to the first marketing approval of the Company’s TCR products. The royalty rates and benchmark payments owed to MD Anderson may be reduced upon the occurrence of certain events. The Company also agreed that it will sell the Company’s TCR products to MD Anderson at preferential prices and will sell its TCR products in Texas exclusively to MD Anderson for a limited period of time following the first commercial sale of the Company’s TCR products. During the years ended December 31, 2020 and 2019, the Company made no payments to MD Anderson. The net balance of cash resources on hand at MD Anderson available to offset expenses and future costs is $8.1 million, which is included in prepaid expenses and other current assets on the Company’s balance sheet on December 31, 2020. The term of the MD Anderson License expires on the last to occur of (a) the expiration of all patents licensed thereunder, or (b) the twentieth anniversary of the date of the MD Anderson License; provided, however, that following the expiration of the term of the MD Anderson License, the Company, together with PGEN, shall then have a fully-paid up, royalty free, perpetual, irrevocable and sublicensable license to use the licensed intellectual property thereunder. After ten years from the date of the MD Anderson License and subject to a 90-day non-exclusive case-by-case 180-day License Agreement with the National Cancer Institute On May 28, 2019, the Company entered into a patent license agreement, or the Patent License, with the National Cancer Institute, or the NCI. Pursuant to the Patent License, the Company holds an exclusive, worldwide license to certain intellectual property to develop and commercialize patient-derived (autologous), peripheral blood T-cell T-cell non-viral non-exclusive, Pursuant to the terms of the Patent License, the Company made payments of $0.5 and $1.0 million during the years ended December 31, 2020 and 2019, respectively. The terms of the Patent License also require the Company to pay the NCI minimum annual royalties in the amount of $0.3 million, which amount will be reduced to $0.1 million once the aggregate minimum annual royalties paid by the Company equals $1.5 million. The first minimum annual royalty payment was paid during the year ending December 31, 2020. On December 31, 2020 and 2019, the Company included $0.3 million related to the Patent License as prepaid expenses and other current assets on the Company’s balance sheet. On December , and , the Company included $ and $ million, respectively in accrued expenses on the Company’s balance sheet. On January , , the Company entered into an amendment to the patent license agreement which expanded the TCR library to include additional TCR’s reactive to mutated KRAS and TP . Under the amendment, the Company paid $ million during the year ending December , . On September , , the Company entered into a second amendment to the patent license agreement which expanded the TCR library to include additional TCR’s receptors. Under the second amendment, the Company paid $ million for the year ended December , . The Company is also required to make performance-based payments upon successful completion of clinical and regulatory benchmarks relating to the licensed products. The aggregate potential benchmark payments are $4.3 million, of which aggregate payments of $3.0 million are due only after marketing approval in the United States or in Europe, Japan, Australia, China or India. The first benchmark payment of $0.1 million will be due upon the initiation of the Company’s first sponsored Phase 1 clinical trial of a licensed product or licensed process in the field of use licensed under the Patent License. There have been no payments as of December 31, 2020. In addition, the Company is required to pay the NCI one-time mid-single ensed product. To the extent the Company enters into a sublicensing agreement relating to a licensed product, the Company is required to pay the NCI a percentage of all consideration received from a sublicensee, which percentage will decrease based on the stage of development of the licensed product at the time of the sublicense. The Patent License will expire upon expiration of the last patent contained in the licensed patent rights, unless terminated earlier. The NCI may terminate or modify the Patent License in the event of a material breach, including if the Company does not meet certain milestones by certain dates, or upon certain insolvency events that remain uncured following the date that is 90 days following written notice of such breach or insolvency event. The Company may terminate the Patent License, or any portion thereof, in the Company’s sole discretion at any time upon 60 days’ written notice to the NCI. In addition, the NCI has the right to: (i) require the Company to sublicense the rights to the product candidates covered by the Patent License upon certain conditions, including if the Company is not reasonably satisfying required health and safety needs and (ii) terminate or modify the Patent License, including if the Company is not satisfying requirements for public use as specified by federal regulations. Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute On January 10, 2017, the Company announced the signing of the CRADA with the NCI for the development of adoptive cell transfer, or ACT,-based immunotherapies genetically modified using the Sleeping Beauty non-viral Sleeping Beauty 20 9 Company made payments of $ million, each year. In February 2019, the Company extended the CRADA with the NCI for two years, committing an additional $ million to this program. Exclusive Channel Partner Agreement with PGEN for the Cancer Programs From 2011 to 2018, the Company was party to various arrangements with Precigen (now PGEN) in which the Company used PGEN’s technology to research and develop cancer treatments in return for various future profit sharing and royalty arrangements. These agreements were modified or terminated by the License Agreement described in Note 7. Ares Trading License and Collaboration Agreement On March 27, 2015, the Company, together with Precigen (now PGEN), signed the Ares Trading Agreement, with Ares Trading S.A., a subsidiary of the biopharmaceutical business of Merck KGaA, Darmstadt, Germany, through which the parties established a collaboration for the research and development and commercialization of certain products for the prophylactic, therapeutic, palliative or diagnostic use for cancer in humans. PGEN was entitled to receive $5.0 million from Ares Trading, payable in equal quarterly installments over two years for each identified product candidate, which will be used to fund discovery work. The Company was responsible for costs exceeding the quarterly installments and all other costs of the preclinical research and development. For the years ended December 31, 2020 and 2019, the Company incurred no expense under the Ares Trading Agreement. For the year ended December 31, 2018, the Company has expensed $0.1 million under the Ares Trading Agreement. Ares Trading paid a non-refundable Under the License Agreement, PGEN agreed to perform all future obligations of the Company under the Ares Trading Agreement other than certain payment obligations. Accordingly, the Company recognized the remaining deferred revenue as part of the settlement of related party relationships as described in Note . Patent and Technology License Agreement—The University of Texas MD Anderson Cancer Center and the Texas A&M University System On August 24, 2004, the Company entered into a patent and technology license agreement with MD Anderson and the Texas A&M University System, which the Company refers to, collectively, as the Licensors. Under this agreement, were granted an exclusive, worldwide license to rights (including rights to U.S. and foreign patent and patent applications and related improvements and know-how) The Company issued options to purchase 50,222 shares outside of its stock option plans following the successful completion of certain clinical milestones, of which all have vested.The Licensors are entitled to receive certain milestone payments. In addition, the Company may be required to make additional payments to the Licensors (as defined in the MD Anderson License) upon achievement of certain other milestones in varying amounts which, on a cumulative basis could total up to $4.5 million. In addition, the Licensors are entitled to receive single digit percentage royalty payments on sales from a licensed product and will also be entitled to receive a portion of any fees that the Company may receive from a possible sublicense under certain circumstances. Collaboration Agreement with Solasia Pharma K.K. On March 7, 2011, the Company entered into a License and Collaboration Agreement with Solasia which was amended on July 31, 2014 to include an exclusive worldwide license. Pursuant to the License and Collaboration Agreement, the Company granted Solasia an exclusive license to develop and commercialize darinaparsin in both intravenous and oral forms and related organic arsenic molecules, in all indications for human use As consideration for the license, the Company is eligible to receive from Solasia development- and sales-based milestones, a royalty on net sales of darinaparsin, once commercialized, and a percentage of any sublicense revenues generated by Solasia. Solasia will be responsible for all costs related to the development, manufacturing and commercialization of darinaparsin. The Company’s Licensors, as defined in the agreement, will receive a portion of all milestone and royalty payments made by Solasia to the Company in accordance with the terms of the license agreement with the Licensors.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2020
Warrants Disclosure [Abstract]
Warrant	10. Warrants In connection with the Company’s November 2018 private placement which provided net proceeds of approximately $47.1 million, the Company issued warrants to purchase an aggregate of 18,939,394 shares of common stock which became exercisable six months after the closing of the private placement. The warrants have an exercise price of $3.01 per share and have a five-year term. The relative fair value of the warrants was estimated at $18.4 million using a Black-Scholes model with the following assumptions: expected volatility of 71%, risk free interest rate of 2.99%, expected life of five years and no dividends. On July 26, 2019 and September 12, 2019, the Company entered into agreements with existing investors for the exercise of previously issued warrants to the agreements, investors exercised their 2018 warrants for an aggregate of shares of common stock, at an exercise price of $ per share. The warrants exercised were originally issued by the Company in a private placement that closed in November 2018. Proceeds from the warrant exercise, after deducting placement agent fees and other related expenses of $ million were approximately $ million. The Company issued participating investors new warrants to purchase up to additional shares of common stock as an inducement for the warrant holders to exercise their 2018 warrants early. The 2019 warrants will become exercisable six months following the date of issuance, will expire on the fifth anniversary of the initial exercise date, and have an exercise price of $ . The 2019 warrants were valued using a Black-Scholes valuation model and resulted in a $ million non-cash charge in the Company’s statement of operations during the year ended December 31, 2019 . The Company assessed whether both the 2019 and 2018 warrants required accounting as derivatives. The Company determined that the warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 815, Derivatives and Hedging On October 22, 2019, the Company entered into the 2019 Agreement with MD Anderson. In connection with the execution of the 2019 Agreement, the Company issued MD Anderson a warrant to purchase 3,333,333 shares of common stock. The warrant has an initial exercise price of $0.001 per share and grant date fair value of $14.5 million. The warrant expires on December 31, 2026 and vests upon the occurrence of certain clinical milestones. The Company will recognize expense on the warrant in the same manner as if the Company paid cash for services to be rendered. For the years ended December 31, 2020 and 2019, the Company did not recognize any expense related to the warrant as no work on the clinical milestones has begun.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	11. Income Taxes There is no provision for income taxes because the Company has incurred operating losses since inception. The reported amount of income tax expense for the years differs from the amount that would result from applying domestic federal statutory tax rates to pretax losses primarily because of the changes in the valuation allowance. Significant components of the Company’s deferred tax assets at December 31, 2020 2019 December 31, (in thousands) 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 147,004 $ 124,115 Start-up 25,909 30,480 Research and development credit carryforwards 37,183 35,130 Stock compensation 1,478 1,087 Capitalized acquisition costs 3,691 4,501 Lease liability 1,225 626 Depreciation 71 176 Other 135 1,186 216,696 197,301 Less valuation allowance (215,513 ) (196,696 ) Total deferred tax assets 1,183 605 Deferred tax liabilities: Right of use asset (1,183 ) (605 ) Total deferred tax liabilities $ (1,183 ) $ (605 ) Net deferred taxes $ — $ — Deferred income taxes reflect the net tax effects of temporary differences between the carrying amount of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. At December 31, 2020 2040 2020 Under the IRC Section 382, certain substantial changes in the Company’s ownership may limit the amount of net operating loss carryforwards that can be utilized in any one year to offset future taxable income. Section 382 of the IRC provides limits to which a corporation that has undergone a change in ownership (as defined) can utilize any net operating loss, or NOL, and general business tax credit carryforwards it may have. The Company commissioned an analysis to determine whether Section 382 could limit the use of its carryforwards in this manner. After completing the analysis, it was determined an ownership change had occurred in February 2007. As a result of this change, the Company’s NOL’s and general business tax credits from February 23, 2007 and prior would be completely limited under IRC Section 382. The deferred tax assets related to NOL’s and general business credits have been reduced by $11.2 million and $636 thousand, respectively, as a result of the change. The Company updated the IRC Section 382 analysis through December 31, 2018. There was no change in ownership at this time. The Company has provided a valuation allowance for the full amount of these net deferred tax assets, since it is more likely than not that these future benefits will not be realized. However, these deferred tax assets may be available to offset future income tax liabilities and expenses. The valuation allowance increased by $18.8 million in 2020 Income taxes using the federal statutory income tax rate differ from the Company’s effective tax rate primarily due to non-deductible A reconciliation of income tax expense (benefit) at the statutory federal income tax rate and income taxes as reflected in the financial statements is as follows: Year Ended December 31, (in thousands) 2020 2019 2018 Federal income tax at statutory rates 21 % 21 % 21 % State income tax, net of federal tax benefit 3 % 3 % 4 % Non-cash 0 % -11 % 0 % Research and development credits 3 % 1 % 2 % Stock compensation -1 % 0 % -1 % Research and development true-up 0 % 0 % 0 % Officers compensation 0 % 0 % -1 % Other 0 % -1 % -2 % Federal rate change -2 % 0 % 3 % Change in valuation allowance -24 % -13 % -26 % Effective tax rate 0 % 0 % 0 % The Company adopted ASC740, “Accounting for Uncertain Tax Positions” on January 1, 2007. ASC 740 clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements in accordance with FASB Statement No. 109, “Accounting for Income Taxes.” ASC 740 prescribes a recognition threshold and measurement of a tax position taken or expected to be taken in a tax return. The Company did not establish any additional reserves for uncertain tax liabilities upon adoption of ASC 740. There were no years ended December 31, 2020, 2019, and 2018. The Company has not recognized any interest and penalties in the statement of operations because of the Company’s net operating losses and tax credits that are available to be carried forward. When necessary, the Company will account for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. The Company does not expect the amounts of unrecognized benefits will change significantly within the next twelve months. The Company is currently open to audit under the statute of limitations by the Internal Revenue Service and state jurisdictions for the years ended December 31, 1999 through 2020. On March 27, 2020, the United States enacted the Coronavirus Aid, Relief, and Economic Security (“CARES”) Act into law which was an emergency economic stimulus package in response to the COVID-19 pandemic and its impact on the economy, public health, state and local governments, individuals and businesses. The Company has considered the legislation surrounding the impact of the CARES Act and the potential effects it may have on the Company. Some of the more significant provisions under the CARES Act include five-year carryback of net operating losses (Section 2303), Refundable AMT credit (Section 2305), relaxation of the limitation of adjusted taxable income (ATI) as determined under IRC Section 163(j) from 30% to 50% (Section 2306), and changes to qualified bonus improvement property (QIP) tax life and bonus depreciation eligibility allowing for a 15

Preferred Stock and Stockholder

Preferred Stock and Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Preferred Stock and Stockholders' Equity (Deficit)	12. Preferred Stock and Stockholders’ Equity (Deficit) On April 26, 2006, the date of the Company’s annual stockholders meeting that year, the shareholders approved the adoption of an Amended and Restated Certificate of Incorporation pursuant to which the Company has 280,000,000 shares of authorized capital stock, of which 250,000,000 shares are designated as common stock (par value $0.001 per share), and 30,000,000 shares are designated as preferred stock (par value $0.001 per share). Common Stock The Company’s amended and res t 24 February 2020 Public Offering On February 5, 2020, the Company entered into an underwriting agreement with Jefferies, as representative of the several underwriters named therein, relating to the issuance and sale of 27,826,086 shares of its common stock. The price to the public in the offering was $3.25 per share, and the underwriters agreed to purchase the shares from the Company pursuant to the underwriting agreement at a purchase price of $3.055 per share. Under the terms of the underwriting agreement, the Company also granted the underwriters an option, exercisable for 30 days, to purchase up to an additional 4,173,912 shares of common stock at a purchase price of $3.055 per share. The offering was made pursuant to the Company’s effective registration statement on Form S-3ASR No. 333-232283) At-the-Market Offering During the year ended December 31, 2020, the Company sold an aggregate of 2,814,673 shares of common stock. The offering was made pursuant to the Company’s effective registration statement on Form S-3ASR (File 333-232283) previously filed with the SEC, and a prospectus supplement thereunder. The net proceeds from the offering were approximately $13.0 million after deducting underwriting discounts and offering expenses payable by the Company. During the year ended De c were approximately $6.1 million after deducting underwriting discounts and offering expenses payable by the Company. November 2018 Private Placement and 2019 Inducement Warrants On November 11, 2018, the Company entered into a securities purchase agreement with certain institutional and accredited investors, pursuant to which the Company agreed to issue and sell to the Investors an aggregate of 18,939,394 immediately separable units, with each unit being composed of (i) one share of the Company’s common stock, par value $0.001 per share, and (ii) a warrant to purchase one share of common stock, at a price per unit of $2.64, for net proceeds of approximately $47.1 million (Note 10). Preferred Stock The Company’s Board of Directors are authorized to designate any series of Preferred Stock, to fix and determine the variations in relative rights, preferences, privileges and restrictions as between and among such series. On June 29, 2016, the Company entered into amendments to certain agreements with Precigen (now PGEN) (Note 7). In consideration for the execution and delivery of these amendments, the Company issued to Precigen 100,000 shares of its newly designated Series 1 preferred stock. Each share of the Company’s Series 1 preferred stock had a stated value of $1,200, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other recapitalization. The Series 1 preferred stock had certain rights, preferences, privileges and obligations, including dividend rights, conversion rights, consent rights with respect to certain Company actions, and rights to preferential payments in the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or a change of control or sale, lease, tran s On October 5, 2018, the Company and PGEN entered into the License Agreement to replace all existing agreements between the companies, which provides the Company with certain exclusive and non-exclusive

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	13. Derivative Financial Instruments The Company determined that certain embedded features related to the Series 1 preferred stock were derivative financial instruments. The company values the embedded derivative financial instruments related to the Series 1 preferred stock as Level 3 financial liabilities (Note 3). On October 5, 2018, the Company entered into the License Agreement with PGEN. In partial consideration for the termination of the former agreements, the Company and PGEN agreed that Precigen would forfeit all outstanding shares of the Series 1 preferred stock held by Precigen, including any accrued dividends and related financial instruments. Thus, upon closing of the transaction, these derivative financial instruments were no longer outstanding (Note 7). The change in the derivative liability for the years ended December 31, 2020, 2019, and 2018 consists of the following: Fair Value Balance, December 31, 2017 $ 2,424 Dividends 223 Change in fair value (158 ) Settlement of a related party relationship (2,489 ) Balance, December 31, 2018 $ — Dividends — Change in fair value — Balance, December 31, 2019 $ — Dividends — Change in fair value — Balance, December 31, 2020 $ — The fair value of the Series 1 preferred stock dividends was estimated using a probability-weighted approach and a Monte Carlo simulation model. The fair value of the embedded derivatives was estimated using the “with” and “without” method where the preferred stock was first valued with all of its features (“with” scenario) and stock change December 31, 2018 Risk-free interest rate 2.50 - 3.13% Expected dividend rate 0 Expected volatility 77.6 - 82.4% Preferred stock conversion limit - percentage of outstanding common stock 19.90% Preferred conversion floor $ 1.00

Stock Option Plan

Stock Option Plan	12 Months Ended
	Dec. 31, 2020
Text Block [Abstract]
Stock Option Plan	14. Stock Option Plan The Company adopted the 2012 Equity Incentive Plan, or the “2012 Plan,” in May 2012. Including subsequent increases, the Company had reserved 14 million shares for issuance. On December 31, 2020, there are 5,659,018 shares reserved for issuance and no shares available for future grant. The Company adopted the 2020 Equity Incentive Plan, or the “2020 Plan,” in June 2020 registered As of December 31, 2020 5,733,1551 Stock options to employees generally vest ratably in either quarterly or annual installments over three or four years, commencing on the first anniversary of the grant date and have contractual terms of ten years. Stock options to directors generally vest ratably over one or two years and have contractual terms of ten years. Stock options are valued using the Black-Scholes option pricing model and compensation is recognized based Proceeds from the option exercises during the years ended December 31, 2020, 2019, and 2018 amounted to $0.4 million, $1.2 million and $0.2 million respectively. The intrinsic value of these options amounted to $0.3 million, $1.1 million and $0.1 million for years ended December 31, 2020, 2019 and 2018, respectively. Transactions under the 2012 Plan and the 2020 Plan for the years ending December , , , and were as follows: (in thousands, except share and per share data) Number of Weighted- Weighted- Aggregate Outstanding, December 31, 2017 3,852,135 $ 5.12 Granted 1,744,950 2.35 Exercised (104,167 ) 2.35 Cancelled (215,833 ) 5.72 Outstanding, December 31, 2018 5,277,085 4.24 Granted 2,880,691 3.40 Exercised (581,105 ) 3.30 Cancelled (1,733,792 ) 4.21 Outstanding, December 31, 2019 5,842,879 3.21 Granted 2,222,368 3.39 Exercised (338,333 ) 2.01 Cancelled (894,528 ) 4.22 Outstanding, December 31, 2020 6,832,386 $ 3.81 7.94 $ 812 Options exercisable, December 31, 2020 3,596,315 $ 4.17 6.90 $ 598 Options exercisable, December 31, 2019 2,765,357 $ 4.39 6.70 $ 3,603 Options available for future grant at December 31, 2020 5,714,648 In September 2017, the Company granted an option for 500,000 inducement stock options, with an exercise price of $6.16 per share, which vests ratably in annual installments over three years, commencing on the first anniversary of the grant date and has a contractual term of ten years. The grant date fair value was $2.2 million. On July 22, 2019, August 19, 2019, and November 21, 2019, the Company granted 400,000, 65,000, and 65,000 inducement stock options, with exercise prices of $5.60, $5.18, and $4.59, respectively. The options vest ratably, over four years, commencing with one quarter on the first anniversary of the grant date and then quarterly thereafter. The options have a contractual term of ten years. These options were granted outside of the 2012 Plan and therefore, are not included in the table above. The grant date fair value was $1.5 million, $231 thousand, and $193 thousand, respectively. As of December 31 , 2020 , 588,333 options are outstanding from all inducement stock options. Restricted Stock In the fiscal years ended December 31, 2020 and 2019, the Company issued 805,900 and 1,519,766 shares of restricted stock, respectively, to employees. and directors. On December 31 , 2020 , total unrecognized compensation costs related to non-vested million. The cost is expected to be recognized over a weighted-average period of 1.78 years. In January 2019 , one of the Company’s executives received 446,428 shares of restricted stock in lieu of their annual cash bonus. The shares were immediately vested. In the year ended December 31 , 2019 , the Company repurchased 225,339 shares at average prices ranging from $2.24 to 4.72 to cover payroll taxes. In the year ended December 31 , 2018 , the Company repurchased 514,349 shares at average prices ranging from $1.70 to 4.41 to cover payroll taxes. A summary of the status of restricted stock as of December 31 , 2020 , 2019 and 2018 is as follows: Number of Weighted-Average Non-vested, 1,808,559 $ 5.74 Granted 150,321 1.87 Vested (1,005,337 ) 6.62 Cancelled (271,433 ) 5.00 Non-vested, 682,110 3.47 Granted 1,519,766 2.44 Vested (1,187,601 ) 2.82 Cancelled (74,599 ) 3.41 Non-vested, 939,676 2.93 Granted 805,900 3.75 Vested (764,360 ) 3.51 Cancelled (194,897 ) 3.44 Non-vested, 786,319 $ 3.08 As of December 31, 2020, there was $1.8 million of total unrecognized stock-based compensation expense related to non- vested

Employee Benefit Plan

Employee Benefit Plan	12 Months Ended
	Dec. 31, 2020
Postemployment Benefits [Abstract]
Employee Benefit Plan	15. Employee Benefit Plan The Company sponsors a qualified 401(k) retirement plan under which employees are allowed to contribute certain percentages of their pay, up to the maximum allowed under Section 401(k) of the IIRC. The Company may make contributions to this plan at its discretion. The Company contributed approximately $538 thousand, $404 thousand, and $329 thousand to this plan during the years ended December 31 , 2020 , 2019 , and 2018 , respectively.

Joint Venture

Joint Venture	12 Months Ended
	Dec. 31, 2020
Equity Method Investments and Joint Ventures [Abstract]
Joint Venture	16. Joint Venture On December 18 , 2018 , the Company entered into a Framework Agreement with TriArm Therapeutics, Ltd., or TriArm, whereby the parties will launch Eden BioCell, Ltd., or Eden BioCell, to lead clinical development and commercialization of certain Sleeping Beauty-generated CAR-T On January 3, 2019, Eden BioCell was incorporated in Hong Kong as a private company. Eden BioCell, the Company and TriArm entered into a Share Subscription Agreement on January 23, 2019 The closing of the transaction occurred on July 5, 2019. The Framework Agreement and Share Subscription Agreements were each respectively amended to be effective as of this date. Upon consummation of the joint venture, Sleeping Beauty CAR-T As of July 5, 2019, as a result of the design and purpose of Eden BioCell, the Company determined that Eden BioCell was considered a variable interest entity, or VIE, and concluded that it is not the primary beneficiary of the VIE as it did not have the power to direct the activities of the VIE that most significantly impact its performance. Rather, the Company accounts for the equity interest in Eden BioCell under the equity method of accounting as it has the ability to exercise significant influence over the operations of Eden BioCell. The Company determined that Eden BioCell was not a customer and therefore, accounted for the transaction as the transfer of nonfinancial assets to be recognized at their fair value on the contribution date. The fair value of the intellectual property contributed to Eden BioCell had a de minimis value due to the early stage of the technology and the likelihood of clinical success. Due to the de minimis fair value of the intellectual property contributed, the Company did not record a gain or loss on this transaction and recognized a value of $0 for the equity-method investment. For the year ended December 31, 2020, Eden Biocell incurred a net loss and the Company continues to have no commitment to fund its operations.

Selected Quarterly Information

Selected Quarterly Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Information (Unaudited)	17. Selected Quarterly Information (Unaudited) (in thousands, except per share amounts) Year Ended December 31, 2020 First Second Third Fourth Revenue $ — $ — $ — $ — Total operating expenses 18,660 18,606 20,321 22,774 Loss from operations (18,660 ) (18,606 ) (20,321 ) (22,774 ) Net income (loss) applicable to common shareholders (18,293 ) (18,596 ) (20,315 ) (22,772 ) Net income (loss) per share, basic $ (0.09 ) $ (0.09 ) $ (0.10 ) $ (0.11 ) Net income (loss) per share, diluted $ (0.09 ) $ (0.09 ) $ (0.10 ) $ (0.11 ) Year Ended December 31, 2019 First Second Third Fourth Revenue $ — $ — $ — $ — Total operating expenses 13,621 14,753 13,448 16,036 Loss from operations (13,621 ) (14,753 ) (13,448 ) (16,036 ) Non-cash — — (60,751 ) — Net income (loss) applicable to common shareholders (13,434 ) (14,620 ) (73,996 ) (15,746 ) Net income (loss) per share, basic $ (0.08 ) $ (0.09 ) $ (0.43 ) $ (0.09 ) Net income (loss) per share, diluted $ (0.08 ) $ (0.09 ) $ (0.43 ) $ (0.09 )

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America or U.S. GAAP.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although the Company regularly assesses these estimates, actual results could differ from those estimates. Changes in estimates are recorded in the period in which they become known. The Company’s most significant estimates and judgments used in the preparation of the financial statements are: • Clinical trial expenses and other research and development expenses; • Collaboration agreements; • Fair value measurements of stock-based compensation and; and • Income taxes.
Impact of COVID-19 Pandemic	Impact of COVID-19 Pandemic With the ongoing COVID-19 COVID-19 COVID-19 healthcare systems and the other risks and uncertainties associated with the COVID-19
Subsequent Events	Subsequent Events The Company evaluated all events and transactions that occurred after the balance sheet date through the date of the Annual Report. Except as disclosed below, the Company did not have any material subsequent events that impacted its financial statements or disclosures. On February 4, 2021, the Company entered into an agreement with Watermill Asset Management Corp. and Robert W. Postma. Pursuant to the Settlement Agreement, the Company increased the size of the Company’s Board of Directors from eight to nine directors and appointed Mr. Postma to fill the newly created directorship. Mr. Postma will serve an initial term expiring at the Company’s 2021 annual meeting of stockholders. Additionally, the Company agreed to nominate each of Mr. Postma, Jaime Vieser and Holger Weis for election at any stockholder meeting at which directors are to be elected and will recommend, support, and solicit proxies for the election of each of Messrs. Postma, Vieser and Weis. Additionally, the Company agreed to reimburse Watermill for up to thousand of its reasonable out-of-pocket fees and expenses. This agreement also resulted in $1.0 million in strategic advisory services becoming due. These costs were expensed during the year ended
Organizational Changes	Organizational Changes During the year ended December 31, 2020 there were changes in the members of the Board of Directors. The following Directors left during the quarter: Scott Braunstein on November 16, 2020, Elan Ezickson on December 3, 2020, and Scott Tarriff on December 15, 2020. Messers. Braunstein and Ezickson received an extended period to exercise stock options along accelerated vesting of restricted stock. In turn, the following Directors joined the board: Mary Thistle on November 15, 2020, Jaime Vieser on December 15, 2020, and Holger Weis on December 15, 2020. On December 10, 2020, Satyavrat Shukla notified the Company of his decision to resign from the position of Chief Financial Officer of the Company, effective December 31, 2020. Included in his separation agreement, Mr. Shukla was to receive his annual bonus which was accrued at December 31, 2020. Additionally, on February 25, 2021, the Company announced that Heidi Hagen, formerly Lead Independent Director, was appointed Interim Chief Executive Officer, replacing Dr. Laurence Cooper, MD., Ph.D. Ms. Hagen is remaining a member of the Board of Directors. Dr. Cooper is also stepping down from his seat on the Board of Directors and is expected to continue with the Company in a scientific advisory capacity to support the Company’s R&D programs.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents consist primarily of demand deposit accounts, certificates of deposit and deposits in short-term U.S. treasury money market mutual funds. Cash equivalents are stated at cost, which approximates fair market value.
Concentrations of Credit Risk	Concentrations of Credit Risk Financial instruments which potentially subject the Company to concentrations of credit risk consist
Property and Equipment	Property and Equipment Property, plant and equipment are stated at cost, less accumulated depreciation and amortization. Expenditures for maintenance and repairs are charged to expense while the costs of significant improvements are capitalized. Depreciation and amortization is calculated on a straight-line basis using the following periods, which represent the estimated useful lives of the assets: ● Office and computer equipment 3 years ● Software 3 years ● Laboratory equipment 5 years ● Leasehold improvements Life of the lease Costs, including certain design, construction and installation costs related to assets that are under construction and are in the process of being readied for their intended use, are recorded as construction in progress and are not depreciated until such time as the subject asset is placed in service. Repairs and maintenance that do not extend the useful life of the asset are expensed as incurred. Upon sale, retirement
Long-Lived Assets	Long-Lived Assets Assessments of long-lived assets and the remaining useful lives of such long-lived assets are reviewed for impairment whenever a triggering event occurs or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. An asset, or group of assets, are considered to be impaired when the undiscounted estimated net cash flows expected to be generated by the asset, or group of assets, are less than its carrying amount. The impairment recognized is the amount by which the carrying amount exceeds the fair market value of the impaired asset, or group of assets, based on the present value of the expected future cash flows associated with the use of the asset.
Operating Segments	Operating Segments Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision maker, the Company’s chief operating decision maker, in making decisions regarding resource allocation and assessing performance. The Company views its operations and manages its business in one operating segment and does not track expenses on a program-by-program
Warrants	Warrants The Company assesses whether warrants issued require accounting as derivatives. The Company determined that the warrants were (1) indexed to the Company’s own stock and (2) classified in stockholders’ equity in accordance with Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 815, Derivatives and Hedging
Fair Value Measurements	The Company has certain financial assets and liabilities recorded at fair value which have been classified as Level 1, 2 or 3 within the fair value hierarchy as described in the accounting standards for fair value measurements. • Level 1—Quoted prices in active markets for identical assets or liabilities. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Assets and liabilities measured at fair value on a recurring basis as of December 31, 2020 and 2019 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 75,990 $ 75,990 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 68,031 $ 68,031 $ — $ — The cash equivalents represent demand deposit accounts and deposits in a short-term United States treasury money market mutual fund quoted in an active market and classified as a Level 1 asset.
Revenue Recognition from Collaboration Agreements	Revenue Recognition from Collaboration Agreements The Company adopted Accounting Standards Codification, or ASC Topic 606, Revenue from Contracts with Customers, its assessment and the implementation resulted in a cumulative effect adjustment to accumulated deficit as of January 1, 2018 of approximately $8.1 million and a corresponding increase to the contract liability (formerly deferred revenue). The adjustment to the Company’s financial statements due to the adoption of ASC 606 is related to the Company’s Ares Trading Agreement (Note 6), which was the Company’s sole open revenue contract outstanding at January 1, 2018. There was no revenue for the years ended December 31, 2020 and 2019. The Company primarily generates revenue through collaboration arrangements with strategic partners for the development and commercialization of product candidates. Commencing January 1, 2018, the Company recognized revenue in accordance with ASC 606 which replaced ASC 605, Multiple Element Arrangements The Company recognizes collaboration revenue under certain of the Company’s license or collaboration agreements that are within the scope of ASC 606. The Company’s contracts with customers typically include promises related to licenses to intellectual property, research and development services and options to purchase additional goods and/or services. If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenue from non-refundable, up-front non-refundable, up-front The terms of the Company’s arrangements with customers typically include the payment of one or more of the following: (i) non-refundable, up-front catch-up payments based upon the achievement of a certain level of product sales, the Company recognizes revenue upon the later of: (i) when the related sales occur or (ii) when the performance obligation to which some or all of the payment has been allocated has been satisfied (or partially satisfied). To date, the Company has not recognized any development, regulatory or commercial milestones or royalty revenue resulting from any of its collaboration arrangements. Consideration that would be received for optional goods and/or services is excluded from the transaction price at contract inception. The Company allocates the transaction price to each performance obligation identified in the contract on a relative standalone selling price basis. However, certain components of variable consideration are allocated specifically to one or more particular performance obligations in a contact to the extent both of the following criteria are met: (i) the terms of the payment relate specifically to the efforts to satisfy the performance obligation or transfer the distinct good or service and (ii) allocating the variable amount of consideration entirely to the performance obligation or the distinct good or service is consistent with the allocation objective of the standard whereby the amount allocated depicts the amount of consideration to which the entity expects to be entitled in exchange for transferring the promised goods or services. The Company develops assumptions that require judgment to determine the standalone selling price for each performance obligation identified in each contract. The key assumptions utilized in determining the standalone selling price for each performance obligation may include forecasted revenues, development timelines, estimated research and development costs, discount rates, likelihood of exercise and probabilities of technical and regulatory success. Revenue is recognized based on the amount of the transaction price that is allocated to each respective performance obligation when or as the performance obligation is satisfied by transferring a promised good and/or service to the customer. For performance obligations that are satisfied over time, the Company recognizes revenue by measuring the progress toward complete satisfaction of the performance obligation using a single method of measuring progress which depicts the performance in transferring control of the associated goods and/or services to the customer. The Company uses input methods to measure the progress toward the complete satisfaction of performance obligations satisfied over time. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Any such adjustments are recorded on a cumulative catch-up The Company recognized the upfront payment received in 2015 associated with a former open contract as a contract liability upon receipt of payment as it requires deferral of revenue recognition to a future period until the Company performs its obligations under the arrangement. Amounts expected to be recognized as revenue within the twelve months following the balance sheet date were classified in current liabilities. Amounts not expected to be recognized as revenue within the twelve months following the balance sheet date were classified as contract liabilities, net of current portion. The Company determined that there were three performance obligations; the first performance obligation consists of the license and research development services and the other two performance obligations are material rights as it relates to potential future targets that have not yet been identified. As described above, the transaction price of $57.5 million was allocated to the performance obligations based on their relative standalone selling prices. There were multiple distinct performance obligations, including material rights; thus, the Company allocated the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost-plus margin. Revenue is recognized by measuring the progress toward complete satisfaction of the performance obligations using an input measure. Furthermore, the Company has not capitalized any contract costs under the guidance in ASC 340-40, Other Assets and Deferred Costs: Contracts with Customers The Company did not believe that any variable consideration should be included in the transaction price at the date of adoption of ASC 606 on January 1, 2018. Such assessment considered the application of the constraint to ensure that estimates of variable consideration would be included in the transaction price only to the extent the Company had a high degree of confidence that revenue would not be reversed in a subsequent reporting period. The Company will re-evaluate the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as other changes in circumstances Impact of Topic 606 Adoption As a result of adopting ASC 606, the Company recorded an $8.1 million adjustment to the opening balance of accumulated deficit in the first quarter of 2018 as a result of the treatment of the up-front d 2015 605-25 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Contract liability, current portion $ 622 $ (5,767 ) $ 6,389 Contract liability, net of current portion $ 49,037 $ 13,898 $ 35,139 Accumulated deficit $ (720,573 ) $ (8,131 ) $ (712,442 ) ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Collaboration revenue $ 146 $ (4,732 ) $ 4,878 Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Net income (loss) applicable to common shareholders $ 137,246 $ (4,732 ) $ 141,978 Net income (loss) per share - basic $ 0.96 $ (0.03 ) $ 0.99 Net income (loss) per share - diluted $ 0.96 $ (0.03 ) $ 0.99 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Net loss $ (53,117 ) $ (4,732 ) $ (48,385) Changes in contract liability $ — $ — $ — The most significant change above relates to the Company’s collaboration revenue, which to date has been exclusively generated from its collaboration arrangement with Ares Trading and PGEN Therapeutics, a wholly owned subsidiary of Precigen Inc., or Precigen, which was formerly known as Intrexon Corporation, ( Note 7 the research and development services which was estimated to be 9 years. In connection , the Company uses cost-based input method to measure were generally consistent with the units of account identified under ASC 605 , the timing of the allocation of the transaction price to the identified performance obligations under ASC 606 differed from the allocations of consideration under ASC 605 . Accordingly, the transaction price ultimately allocated to each performance obligation under ASC 606 differed from the amounts allocated under ASC 605 . Additionally, at December 31 , 2018 , the contract liability is $0 under both methods of revenue recognition (Note 7) . There is no revenue related to the years ended December 31 , 2020 and 2019 .
Research and Development Costs	Research and Development Costs As part of the process of preparing our financial statements estimate • CROs in connection with performing research services on our behalf and clinical trials, • investigative sites or other providers in connection with clinical trials, • vendors in connection with preclinical and clinical development activities, and • vendors related to product manufacturing, development, and distribution of preclinical and clinical supplies. We base our expenses related to preclinical studies and clinical trials on our estimates of the services received and efforts expended pursuant to quotes and contracts with multiple CROs that conduct and manage clinical trials on our behalf. The financial terms of these agreements are subject to negotiation, vary from contract to contract and may result in uneven payment flows. There may be instances in which payments made to our vendors will exceed the level of services provided and result in a prepayment of the clinical expense. Payments under some of these contracts depend on factors such as the completion of clinical trial milestones. In accruing service fees, we estimate the time period over which services will be performed, enrollment of patients, number of sites activated and the level of effort to be expended in each period. If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrual or amount of prepaid expense accordingly. Although we do not expect our estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and may result in us reporting amounts that are too high or too low in any particular period. To date, we have not made any material adjustments to our prior estimates of accrued research and development expenses.
Income Taxes	Income taxes are accounted for under the liability method. Deferred tax assets and liabilities are recognized for the estimated future tax consequences of temporary differences between the financial statement carrying amounts and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which the temporary differences are expected to be recovered or settled. The Company evaluates the realizability of its deferred tax assets and establishes a valuation allowance when it is more likely than not that all or a portion of deferred tax assets will not be realized. The Company accounts for uncertain tax positions using a “more-likely-than-not”
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation Stock-based compensation cost is measured at the grant date, based on the estimated fair value of the award, and is recognized as expense over the employee’s requisite service period. Stock-based compensation expense is based on the number of awards ultimately expected to vest and is therefore reduced for an estimate of the awards that are expected to be forfeited prior to vesting. Consistent with prior years, the Company uses the Black-Scholes option pricing model which requires estimates of the expected term option holders will retain their options before exercising them and the estimated volatility of the Company’s common stock price over the expected term. The Company recognizes the full impact of its share-based employee payment plans in the statements of operations for each of the years ended December 31, 2020, 2019, and 2018 and did not capitalize any such costs on the balance sheets. The Company recognized $4.3 million, $4.0 million, and $3.0 million of compensation expense related to stock options during the years ended December 31, 2020, 2019, and 2018, respectively. In the years ended December 31, 2020, 2019, and 2018, the Company recognized $2.5 million, $2.3 million, and $4.5 million of compensation expense, respectively, related to restricted stock (Note 14). The total compensation expense relating to vesting of stock options and restricted stock awards for the years ended December 31, 2020, 2019, and 2018 was $6.8 million, $6.3 million, and $7.5 million, respectively.The following table presents share-based compensation expense included in the Company’s Statements of Operations: Year ended December 31, (in thousands) 2020 2019 2018 Research and development $ 2,098 $ 1,461 $ 1,683 General and administrative 4,731 4,880 5,851 Share based employee compensation expense before tax 6,829 6,341 7,534 Income tax benefit — — — Net share based employee compensation expense $ 6,829 $ 6,341 $ 7,534 The fair value of each stock option is estimated at the date of grant using the Black-Scholes option pricing model. The estimated weighted-average fair value of stock options granted to employees in 2020, 2019, and 2018 was 2020 2019 2018 Weighted average risk-free interest rate 0.36 - 1.68% 1.39 - 2.53% 2.55 - 3.06% Expected life in years 5.75 - 6.25 5.75 - 6.25 6 Expected volatility 71.11 - 74.41% 71.39 - 85.00% 80.75 - 84.71% Expected dividend yield 0 0 0 approximately volatility, expected . 107 and No . 110 as it continues to meet the requirements promulgated in SAB No . 110 . The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below:
Net Income (Loss) Per Share	Net Income (Loss) Per Share Basic net loss per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. For the Year Ended December 31, in thousands, except share and per share data 2020 2019 2018 Basic Net loss $ (79,976 ) $ (117,796 ) $ (53,117 ) Preferred stock dividends — — (16,998 ) Settlement of a related party relationship — — 207,361 Net income / (loss) applicable to common shareholders $ (79,976 ) $ (117,796 ) $ 137,246 Weighted-average common shares outstanding 209,636,456 167,952,114 143,508,674 Earnings per share, basic $ (0.38 ) $ (0.70 ) $ 0.96 Diluted Net Loss $ (79,976 ) $ (117,796 ) $ (53,117 ) Preferred stock dividends — — (16,998 ) Precigen license transaction — — 207,361 Net income / (loss) applicable to common shareholders $ (79,976 ) $ (117,796 ) $ 137,246 Weighted-average common shares outstanding 209,636,456 167,952,114 143,508,674 For the Year Ended December 31, in thousands, except share and per share data 2020 2019 2018 Effect of dilutive securities Stock options — — 201,362 Unvested restricted common stock — — 124 Warrants — — — Dilutive potential common shares — — 201,486 Shares used in calculating diluted earnings per share 209,636,456 167,952,114 143,710,160 Earnings per share, diluted $ (0.38 ) $ (0.70 ) $ 0.96 Certain shares related to some of the Company’s outstanding common stock options, unvested restricted stock, preferred stock, and warrants have not been included in the computation of diluted net earnings (loss) per share for the years ended December , , and as the result would be , , , and consist of the following: December 31, 2020 2019 2018 Stock options 6,832,386 6,872,879 5,075,723 Inducement stock options 588,333 1,030,000 500,000 Unvested restricted stock 786,280 939,636 681,946 Warrants 22,272,727 22,272,727 18,939,394 30,479,726 31,115,242 25,197,063 During the year ended December 31, 2018, the Company and PGEN entered into a License Agreement to replace all existing agreements between the companies that provides the Company with certain exclusive and non-exclusive
New Accounting Pronouncements	New Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes 2019-12

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis as of December 31, 2020 and 2019 are as follows: ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 75,990 $ 75,990 $ — $ — ($ in thousands) Fair Value Measurements at Reporting Date Using Description Balance as of Quoted Prices in Significant Other Significant Cash equivalents $ 68,031 $ 68,031 $ — $ —
Impact of Topic 606 Adoption on Financial Statements	Impact of Topic 606 Adoption As a result of adopting ASC 606, the Company recorded an $8.1 million adjustment to the opening balance of accumulated deficit in the first quarter of 2018 as a result of the treatment of the up-front d 2015 605-25 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Contract liability, current portion $ 622 $ (5,767 ) $ 6,389 Contract liability, net of current portion $ 49,037 $ 13,898 $ 35,139 Accumulated deficit $ (720,573 ) $ (8,131 ) $ (712,442 ) ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Collaboration revenue $ 146 $ (4,732 ) $ 4,878 Net loss $ (53,117 ) $ (4,732 ) $ (48,385 ) Net income (loss) applicable to common shareholders $ 137,246 $ (4,732 ) $ 141,978 Net income (loss) per share - basic $ 0.96 $ (0.03 ) $ 0.99 Net income (loss) per share - diluted $ 0.96 $ (0.03 ) $ 0.99 ($ in thousands) Impact of Topic 606 Adoption Description As reported under Adjustments Balances without Net loss $ (53,117 ) $ (4,732 ) $ (48,385) Changes in contract liability $ — $ — $ —
Share-Based Compensation Expense Included in Statements of Operations	The following table presents share-based compensation expense included in the Company’s Statements of Operations: Year ended December 31, (in thousands) 2020 2019 2018 Research and development $ 2,098 $ 1,461 $ 1,683 General and administrative 4,731 4,880 5,851 Share based employee compensation expense before tax 6,829 6,341 7,534 Income tax benefit — — — Net share based employee compensation expense $ 6,829 $ 6,341 $ 7,534
Assumptions for Volatility, Expected life, Dividend Yield and Risk-free Interest Rate	The assumptions for volatility, expected life, dividend yield and risk-free interest rate are presented in the table below: 2020 2019 2018 Weighted average risk-free interest rate 0.36 - 1.68% 1.39 - 2.53% 2.55 - 3.06% Expected life in years 5.75 - 6.25 5.75 - 6.25 6 Expected volatility 71.11 - 74.41% 71.39 - 85.00% 80.75 - 84.71% Expected dividend yield 0 0 0
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method	Basic net loss per share is computed by dividing net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period, plus the dilutive effect of outstanding options and warrants, using the treasury stock method and the average market price of the Company’s common stock during the applicable period. For the Year Ended December 31, in thousands, except share and per share data 2020 2019 2018 Basic Net loss $ (79,976 ) $ (117,796 ) $ (53,117 ) Preferred stock dividends — — (16,998 ) Settlement of a related party relationship — — 207,361 Net income / (loss) applicable to common shareholders $ (79,976 ) $ (117,796 ) $ 137,246 Weighted-average common shares outstanding 209,636,456 167,952,114 143,508,674 Earnings per share, basic $ (0.38 ) $ (0.70 ) $ 0.96 Diluted Net Loss $ (79,976 ) $ (117,796 ) $ (53,117 ) Preferred stock dividends — — (16,998 ) Precigen license transaction — — 207,361 Net income / (loss) applicable to common shareholders $ (79,976 ) $ (117,796 ) $ 137,246 Weighted-average common shares outstanding 209,636,456 167,952,114 143,508,674 For the Year Ended December 31, in thousands, except share and per share data 2020 2019 2018 Effect of dilutive securities Stock options — — 201,362 Unvested restricted common stock — — 124 Warrants — — — Dilutive potential common shares — — 201,486 Shares used in calculating diluted earnings per share 209,636,456 167,952,114 143,710,160 Earnings per share, diluted $ (0.38 ) $ (0.70 ) $ 0.96
Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share	Such potential common shares on December 31 , , , and consist of the following: December 31, 2020 2019 2018 Stock options 6,832,386 6,872,879 5,075,723 Inducement stock options 588,333 1,030,000 500,000 Unvested restricted stock 786,280 939,636 681,946 Warrants 22,272,727 22,272,727 18,939,394 30,479,726 31,115,242 25,197,063

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Component of Property and Equipment, Net	Property and equipment, net, consists of the following: December 31, (in thousands) 2020 2019 Office and computer equipment $ 869 $ 1,436 Software 1,153 1,030 Leasehold improvements 7,457 1,195 Research and development equipment 5,401 1,892 Construction - in-process 313 389 15,193 5,942 Less: accumulated depreciation (4,962 ) (4,832 ) Property and equipment, net $ 10,231 $ 1,110

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Payables and Accruals [Abstract]
Component of Accrued Expenses	Accrued expenses consist of the following: December 31, (in thousands) 2020 2019 Clinical services $ 4,450 $ 5,247 Employee compensation 3,298 1,910 Preclinical services 749 1,147 Professional services 3,993 991 Manufacturing services 3,159 586 Accrued vacation 725 489 Payroll taxes and benefits 16 284 Other consulting services 199 192 Total $ 16,589 $ 10,846

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases, Operating [Abstract]
Components of Lease Expense	The components of lease expense were as follows: Years Ended December 31, 2020 2019 Operating lease cost $ 1,054 $ 772 Total lease cost $ 1,054 $ 772 Weighted-average remaining lease term (years) 6.19 4.42 Weighted-average discount rate 8.00 % 8.00 %
Lessee, Operating Lease, Liability, Maturity	As of December 31, 2020, the maturities of the Company’s operating lease liabilities Maturity of Lease Liabilities Operating Leases 2021 $ 1,189 2022 800 2023 820 2024 844 2025 869 Thereafter 1,650 Total lease payments $ 6,172 Less : imputed interest and adjustments (1,358 ) Present value of lease payments $ 4,814

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Significant Component of Deferred Tax Assets	Significant components of the Company’s deferred tax assets at December 31, 2020 2019 December 31, (in thousands) 2020 2019 Deferred tax assets: Net operating loss carryforwards $ 147,004 $ 124,115 Start-up 25,909 30,480 Research and development credit carryforwards 37,183 35,130 Stock compensation 1,478 1,087 Capitalized acquisition costs 3,691 4,501 Lease liability 1,225 626 Depreciation 71 176 Other 135 1,186 216,696 197,301 Less valuation allowance (215,513 ) (196,696 ) Total deferred tax assets 1,183 605 Deferred tax liabilities: Right of use asset (1,183 ) (605 ) Total deferred tax liabilities $ (1,183 ) $ (605 ) Net deferred taxes $ — $ —
Reconciliation of Income Tax Expense (Benefit)	A reconciliation of income tax expense (benefit) at the statutory federal income tax rate and income taxes as reflected in the financial statements is as follows: Year Ended December 31, (in thousands) 2020 2019 2018 Federal income tax at statutory rates 21 % 21 % 21 % State income tax, net of federal tax benefit 3 % 3 % 4 % Non-cash 0 % -11 % 0 % Research and development credits 3 % 1 % 2 % Stock compensation -1 % 0 % -1 % Research and development true-up 0 % 0 % 0 % Officers compensation 0 % 0 % -1 % Other 0 % -1 % -2 % Federal rate change -2 % 0 % 3 % Change in valuation allowance -24 % -13 % -26 % Effective tax rate 0 % 0 % 0 %

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Change in Derivative Liability	The change in the derivative liability for the years ended December 31, 2020, 2019, and 2018 consists of the following: Fair Value Balance, December 31, 2017 $ 2,424 Dividends 223 Change in fair value (158 ) Settlement of a related party relationship (2,489 ) Balance, December 31, 2018 $ — Dividends — Change in fair value — Balance, December 31, 2019 $ — Dividends — Change in fair value — Balance, December 31, 2020 $ —
Fair Value Assumptions Used in Probability Weighted Approach and Monte Carlo Simulation Model	The fair value of the Series 1 preferred stock dividends was estimated using a probability-weighted approach and a Monte Carlo simulation model. The fair value of the embedded derivatives was estimated using the “with” and “without” method where the preferred stock was first valued with all of its features (“with” scenario) and stock change December 31, 2018 Risk-free interest rate 2.50 - 3.13% Expected dividend rate 0 Expected volatility 77.6 - 82.4% Preferred stock conversion limit - percentage of outstanding common stock 19.90% Preferred conversion floor $ 1.00

Stock Option Plans (Tables)

Stock Option Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Text Block [Abstract]
Transaction under Stock Option Plan	Transactions under the 2012 Plan and the 2020 Plan for the years ending December , , , and were as follows: (in thousands, except share and per share data) Number of Weighted- Weighted- Aggregate Outstanding, December 31, 2017 3,852,135 $ 5.12 Granted 1,744,950 2.35 Exercised (104,167 ) 2.35 Cancelled (215,833 ) 5.72 Outstanding, December 31, 2018 5,277,085 4.24 Granted 2,880,691 3.40 Exercised (581,105 ) 3.30 Cancelled (1,733,792 ) 4.21 Outstanding, December 31, 2019 5,842,879 3.21 Granted 2,222,368 3.39 Exercised (338,333 ) 2.01 Cancelled (894,528 ) 4.22 Outstanding, December 31, 2020 6,832,386 $ 3.81 7.94 $ 812 Options exercisable, December 31, 2020 3,596,315 $ 4.17 6.90 $ 598 Options exercisable, December 31, 2019 2,765,357 $ 4.39 6.70 $ 3,603 Options available for future grant at December 31, 2020 5,714,648 In September 2017, the Company granted an option for 500,000 inducement stock options, with an exercise price of $6.16 per share, which vests ratably in annual installments over three years, commencing on the first anniversary of the grant date and has a contractual term of ten years. The grant date fair value was $2.2 million. On July 22, 2019, August 19, 2019, and November 21, 2019, the Company granted 400,000, 65,000, and 65,000 inducement stock options, with exercise prices of $5.60, $5.18, and $4.59, respectively. The options vest ratably,
Summary of Non-Vested Restricted Stock	A summary of the status of restricted stock as of December 31 , 2020 , 2019 and 2018 is as follows: Number of Weighted-Average Non-vested, 1,808,559 $ 5.74 Granted 150,321 1.87 Vested (1,005,337 ) 6.62 Cancelled (271,433 ) 5.00 Non-vested, 682,110 3.47 Granted 1,519,766 2.44 Vested (1,187,601 ) 2.82 Cancelled (74,599 ) 3.41 Non-vested, 939,676 2.93 Granted 805,900 3.75 Vested (764,360 ) 3.51 Cancelled (194,897 ) 3.44 Non-vested, 786,319 $ 3.08

Selected Quarterly Informatio_2

Selected Quarterly Information (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Information	Year Ended December 31, 2020 First Second Third Fourth Revenue $ — $ — $ — $ — Total operating expenses 18,660 18,606 20,321 22,774 Loss from operations (18,660 ) (18,606 ) (20,321 ) (22,774 ) Net income (loss) applicable to common shareholders (18,293 ) (18,596 ) (20,315 ) (22,772 ) Net income (loss) per share, basic $ (0.09 ) $ (0.09 ) $ (0.10 ) $ (0.11 ) Net income (loss) per share, diluted $ (0.09 ) $ (0.09 ) $ (0.10 ) $ (0.11 ) Year Ended December 31, 2019 First Second Third Fourth Revenue $ — $ — $ — $ — Total operating expenses 13,621 14,753 13,448 16,036 Loss from operations (13,621 ) (14,753 ) (13,448 ) (16,036 ) Non-cash — — (60,751 ) — Net income (loss) applicable to common shareholders (13,434 ) (14,620 ) (73,996 ) (15,746 ) Net income (loss) per share, basic $ (0.08 ) $ (0.09 ) $ (0.43 ) $ (0.09 ) Net income (loss) per share, diluted $ (0.08 ) $ (0.09 ) $ (0.43 ) $ (0.09 )

Organization - Additional Infor

Organization - Additional Information (Detail) - USD ($) $ in Thousands	Feb. 24, 2021	Dec. 31, 2020	Feb. 24, 2020	Dec. 31, 2019	Dec. 31, 2017	Apr. 26, 2006
Cash and cash equivalents		$ 115,069		$ 79,741
Accumulated deficit		$ (764,101)		$ (684,125)	$ (712,442)
Common stock, shares authorized		250,000,000		250,000,000		250,000,000
Common stock, shares outstanding		214,591,906		181,803,320
Common stock reserved for future issuance	31,115,329
Common Stock
Common stock, shares authorized			250,000,000
Common stock, shares outstanding	214,667,023		214,667,023
Common stock reserved for future issuance			31,115,329

Financings - Additional Informa

Financings - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Mar. 10, 2020	Feb. 05, 2020	Sep. 12, 2019	Nov. 11, 2018	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Apr. 26, 2006
Class of Stock [Line Items]
Stock issued during period						2,814,673
Sale of stock consideration received on transaction						$ 88,661
Common stock, par value				$ 0.001		$ 0.001	$ 0.001	$ 0.001
Gross proceeds received						$ 13,016	$ 6,085
Class of warrant or right, number of securities called by warrants or rights				18,939,394
Warrant Exercise Price per share				$ 2.64
Proceeds from private placement			$ 52,500
Non-cash inducement warrant expense					$ (60,751)		$ 60,751
At The Market Offering [Member]
Class of Stock [Line Items]
Stock issued during period						2,814,673	1,271,274
Sale of stock consideration received on transaction						$ 13,000	$ 6,100
Private Placement [Member]
Class of Stock [Line Items]
Class of warrant or right, number of securities called by warrants or rights			17,803,031			18,939,394
Warrant Exercise Price per share			$ 3.01			$ 3.01
Placement agent fees and other expenses			$ 1,100
Private Placement [Member] | New Warrants [Member]
Class of Stock [Line Items]
Class of warrant or right, number of securities called by warrants or rights			17,803,031
Warrant Exercise Price per share			$ 7
Non-cash inducement warrant expense			$ 60,800			$ 60,800
Securities Purchase Agreement [Member]
Class of Stock [Line Items]
Stock issued during period				18,939,394
Common stock, par value				$ 0.001
par value per share				$ 2.64
Gross proceeds received				$ 47,100		47,100
Underwriting Agreement [Member]
Class of Stock [Line Items]
Stock issued during period		27,826,086					1,271,274
Issuance & sale of common stock in public offering price per share		$ 3.25
Sale of stock consideration received on transaction		$ 84,800				$ 13,000	$ 6,100
par value per share		$ 3.055
Underwriting Agreement [Member] | Maximum [Member]
Class of Stock [Line Items]
Stock issued during period		4,173,912
par value per share		$ 3.055
Underwriting Agreement [Member] | Stock Option [Member]
Class of Stock [Line Items]
Sale of stock consideration received on transaction	$ 3,900
Stock issued during period	1,284,025

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jan. 02, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 04, 2021	Jan. 01, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses		$ 6,829	$ 6,341	$ 7,534
Weighted average fair value of stock option granted		$ 2.15	$ 2.47	$ 1.64
Accumulated deficit		$ (764,101)	$ (684,125)				$ (712,442)
Transaction Price		57,500
Changes in contract liability				$ (146)
Strategic advisory services fee		$ 1,000
Office and computer equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life		3 years
Software
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life		3 years
Laboratory equipment
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life		5 years
Leasehold improvements
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life		Life of the lease
Difference between revenue guidance in effect before and after topic 606
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit						$ 8,100
Research and Development Services Contract Term		9 years
Changes in contract liability	$ 8,100
Stock Options
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses		$ 4,300	4,000	3,000
Restricted Stock
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses		2,500	2,300	4,500
Restricted Stock Units (RSUs) [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock based compensation expenses		6,800	6,300	7,500
Accrued Expenses [Member]
Summary Of Significant Accounting Policies [Line Items]
Cost Incurred in appointment of directors		$ 0
Subsequent Event
Summary Of Significant Accounting Policies [Line Items]
Reimbursement of expenses due					$ 400
ASU 2014-09
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit							(720,573)
ASU 2014-09 | Difference between revenue guidance in effect before and after topic 606
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit							$ (8,131)
Changes in contract liability			$ 0	$ 0

Assets and Liabilities Measured

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 75,990	$ 68,031
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 75,990	$ 68,031

Impact of Topic 606 Adoption on

Impact of Topic 606 Adoption on Financial Statements (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jan. 02, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liability, current portion														$ 6,389
Contract liability, net of current portion														35,139
Accumulated deficit		$ (764,101)				$ (684,125)				$ (764,101)	$ (684,125)			(712,442)
Collaboration revenue		0	$ 0	$ 0	$ 0							$ 146
Net loss		$ (22,772)	$ (20,315)	$ (18,596)	$ (18,293)	$ (15,746)	$ (73,996)	$ (14,620)	$ (13,434)	(79,976)	(117,796)	(53,117)
Net income (loss) applicable to common shareholders										$ (79,976)	$ (117,796)	$ 137,246
Net income (loss) per share—basic		$ (0.11)	$ (0.10)	$ (0.09)	$ (0.09)	$ (0.09)	$ (0.43)	$ (0.09)	$ (0.08)	$ (0.38)	$ (0.70)	$ 0.96
Net income (loss) per share—diluted		$ (0.11)	$ (0.10)	$ (0.09)	$ (0.09)	$ (0.09)	$ (0.43)	$ (0.09)	$ (0.08)	$ (0.38)	$ (0.70)	$ 0.96
Net loss		$ (22,772)	$ (20,315)	$ (18,596)	$ (18,293)	$ (15,746)	$ (73,996)	$ (14,620)	$ (13,434)	$ (79,976)	$ (117,796)	$ (53,117)
Changes in contract liability												(146)
ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liability, current portion														622
Contract liability, net of current portion														49,037
Accumulated deficit														(720,573)
Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accumulated deficit													$ 8,100
Changes in contract liability	$ 8,100
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract liability, current portion														(5,767)
Contract liability, net of current portion														13,898
Accumulated deficit														$ (8,131)
Collaboration revenue												(4,732)
Net loss												(4,732)
Net income (loss) applicable to common shareholders												$ (4,732)
Net income (loss) per share—basic												$ (0.03)
Net income (loss) per share—diluted												$ (0.03)
Net loss												$ (4,732)
Changes in contract liability											$ 0	0
Calculated under Revenue Guidance in Effect before Topic 606 | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Collaboration revenue												4,878
Net loss												(48,385)
Net income (loss) applicable to common shareholders												$ 141,978
Net income (loss) per share—basic												$ 0.99
Net income (loss) per share—diluted												$ 0.99
Net loss												$ (48,385)

Stock-Based Compensation Expens

Stock-Based Compensation Expense Included in Statement of Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 6,829	$ 6,341	$ 7,534
Net share based employee compensation expense	6,829	6,341	7,534
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	2,098	1,461	1,683
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 4,731	$ 4,880	$ 5,851

Fair Value of Stock Options Ass

Fair Value of Stock Options Assumptions Using Black-Scholes Option Valuation Model (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Risk-free interest rate, Minimum	0.36%	1.39%	2.55%
Risk-free interest rate, Maximum	1.68%	2.53%	3.06%
Expected life in years			6 years
Expected volatility, Minimum	71.11%	71.39%	80.75%
Expected volatility, Maximum	74.41%	85.00%	84.71%
Expected dividend yield	0.00%	0.00%	0.00%
Maximum [Member]
Expected life in years	6 years 3 months	6 years 3 months
Minimum [Member]
Expected life in years	5 years 9 months	5 years 9 months

Earning Per share Basic and Dil

Earning Per share Basic and Diluted (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share, Basic [Abstract]
Net loss	$ (22,772)	$ (20,315)	$ (18,596)	$ (18,293)	$ (15,746)	$ (73,996)	$ (14,620)	$ (13,434)	$ (79,976)	$ (117,796)	$ (53,117)
Preferred stock dividends											(16,998)
Settlement of a related party relationship											207,361
Net income (loss) applicable to common stockholders									$ (79,976)	$ (117,796)	$ 137,246
Weighted-average common shares outstanding									209,636,456	167,952,114	143,508,674
Earnings per share, basic	$ (0.11)	$ (0.10)	$ (0.09)	$ (0.09)	$ (0.09)	$ (0.43)	$ (0.09)	$ (0.08)	$ (0.38)	$ (0.70)	$ 0.96
Earnings Per Share, Diluted [Abstract]
Net loss	$ (22,772)	$ (20,315)	$ (18,596)	$ (18,293)	$ (15,746)	$ (73,996)	$ (14,620)	$ (13,434)	$ (79,976)	$ (117,796)	$ (53,117)
Preferred stock dividends											(16,998)
Precigen license transaction											207,361
Net income (loss) applicable to common stockholders									$ (79,976)	$ (117,796)	$ 137,246
Weighted-average common shares outstanding									209,636,456	167,952,114	143,508,674
Effect of dilutive securities
Stock options											201,362
Unvested restricted common stock											124
Dilutive potential common shares											$ 201,486
Shares used in calculating diluted earnings per share									209,636,456	167,952,114	143,710,160
Earnings per share, diluted	$ (0.11)	$ (0.10)	$ (0.09)	$ (0.09)	$ (0.09)	$ (0.43)	$ (0.09)	$ (0.08)	$ (0.38)	$ (0.70)	$ 0.96

Potential Dilutive Shares Exclu

Potential Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	30,479,726	31,115,242	25,197,063
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	22,272,727	22,272,727	18,939,394
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	6,832,386	6,872,879	5,075,723
Stock Options | Two Thousand Twelve Stock Option Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	588,333	1,030,000	500,000
Unvested Restricted Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	786,280	939,636	681,946

Component of Property and Equip

Component of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 15,193	$ 5,942
Less: accumulated depreciation	(4,962)	(4,832)
Property and equipment, net	10,231	1,110
Office and computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	869	1,436
Software
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	1,153	1,030
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	7,457	1,195
Research and development equipment
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	5,401	1,892
Construction-in-process
Property, Plant and Equipment [Line Items]
Property and equipment, Gross	$ 313	$ 389

Property and Equipment, net - A

Property and Equipment, net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Depreciation	$ 1,128	$ 629	$ 575

Component of Accrued Expenses (

Component of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Clinical services	$ 4,450	$ 5,247
Employee compensation	3,298	1,910
Preclinical services	749	1,147
Manufacturing services	3,159	586
Professional services	3,993	991
Accrued vacation	725	489
Payroll taxes and benefits	16	284
Other consulting services	199	192
Total	$ 16,589	$ 10,846

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Oct. 05, 2018	Jun. 29, 2016	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2015
Related Party Transaction [Line Items]
Change in fair value of derivative liability			$ 0	$ 0	$ 158,000
Amounts expensed for services incurred			80,361,000	57,858,000	54,052,000
Research and development expense			52,696,000	38,331,000	34,134,000
Expenses From Transactions With Related Party					2,000,000
MD Anderson License and the Research and Development Agreement Member [Member]
Related Party Transaction [Line Items]
Cash resources on hand			8,100,000
Series 1 Preferred Stock
Related Party Transaction [Line Items]
Temporary equity, fair value			18,900,000
Change in fair value of derivative liability			1,300
Expenses From Transactions With Related Party	$ 5,400,000
License Agreement | M.D. Anderson Cancer Center
Related Party Transaction [Line Items]
Issuance of common stock in licensing agreement (in shares)						11,722,163
Research and development expense						$ 67,300,000
Cooperative Research and Development Agreement | M.D. Anderson Cancer Center
Related Party Transaction [Line Items]
Research and development service agreement aggregate payments			41,900,000	41,900,000	41,900,000
Intrexon Corporation/Precigen
Related Party Transaction [Line Items]
Amounts expensed for services incurred			$ 100,000	3,000,000	$ 8,100,000
Amount due to related party, current				$ 100,000
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Related Party Transaction [Line Items]
Issuance of common stock in licensing agreement (in shares)		100,000	11,415
Vineti Inc | Collaborative Arrangement
Related Party Transaction [Line Items]
Expenses From Transactions With Related Party			$ 29,000
Eden BioCell [Member]
Related Party Transaction [Line Items]
Payments to Fund Long-term Loans to Related Parties			10,000,000
Additional Loans Committed			$ 25,000,000

Settlement of a Related Party_2

Settlement of a Related Party Relationship - Additional Information (Detail) - USD ($) $ in Thousands	Oct. 05, 2018	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Transaction advisory costs recognized as expense		$ 2,000
Preferred Stock Redemption Discount		$ 207,361
Accrued expenses			$ 16,589	$ 10,846
Related Party Liability				100
Precigen
Annual Licensing fee			100
Accrued expenses			$ 100	$ 100
Intrexon Corporation/Precigen
Preferred stock, contract liability, derivative liability	$ 163,300
Increase in accumulated deficit	49,500
Related party transaction, amounts of transaction	212,800
Additional milestone payment for exclusively licensed program to be paid	52,500
Maximum Royalty payable	$ 100,000
Percentage of sublicensing income	20.00%
Royalty payment to be received	$ 50,000
Third Party Vendor
Transaction advisory costs recognized as expense	7,400
Series 1 Preferred Stock [Member]
Transaction advisory costs recognized as expense	5,400
Series 1 Preferred Stock [Member] | Intrexon Corporation/Precigen
Consideration transferred	207,300
Preferred Stock Redemption Discount	$ 5,400

Lease expense (Detail)

Lease expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating lease cost	$ 1,054	$ 772
Total lease cost	$ 1,054	$ 772
Weighted-average remaining lease term (years)	6 years 2 months 8 days	4 years 5 months 1 day
Weighted-average discount rate	8.00%	8.00%

Operating lease liabilities (De

Operating lease liabilities (Detail) $ in Thousands	Dec. 31, 2020USD ($)
2021	$ 1,189
2022	800
2023	820
2024	844
2025	869
Thereafter	1,650
Total lease payments	6,172
Less: imputed interest and adjustments	(1,358)
Present value of lease payments	$ 4,814
Operating lease liability statement of financial position [extensible list]	us-gaap:OperatingLeaseLiability

Leases - Additional Information

Leases - Additional Information (Details)	Dec. 15, 2020USD ($)	Sep. 01, 2020USD ($)	Jun. 01, 2020USD ($)	Apr. 13, 2020USD ($)	Oct. 15, 2019USD ($)ft²	Mar. 12, 2019USD ($)ft²	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Jan. 01, 2019USD ($)	Jan. 30, 2018USD ($)ft²
Land Subject to Ground Leases | ft²						1,038
Operating Lease Monthly Rental Payment			$ 10,000			$ 2,000
Operating Lease, Payments							$ 1,000,000
Operating Lease, Right-of-Use Asset							4,650,000	$ 2,272,000
Operating Lease, Liability							4,814,000
Recognisition in exchange of Operating Lease Liabilities							3,200,000
Adjustments for New Accounting Pronouncement [Member]
Operating Lease, Right-of-Use Asset									$ 1,600,000
Operating Lease, Liability									$ 1,600,000
Boston, MA
Security Deposit							$ 100,000	$ 100,000
Sublease term amendment							Aug. 31, 2021
Operating lease expiration month and year							2016-08
Houston, TX
Land Subject to Ground Leases | ft²					8,443					210
Operating Leases Future Minimum Monthly Payment Due Through Year 2021	$ 37,000			$ 12,000	$ 17,000					$ 1,000
Annual Base Rent	3.00%			3.00%	3.00%
Lessee Operating Lease Monthly Rental Payment		$ 15,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)

May 28, 2019

Jan. 13, 2015

Jul. 31, 2015

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Dec. 31, 2017

Nov. 28, 2020

Oct. 22, 2019

Feb. 19, 2019

Nov. 11, 2018

Dec. 31, 2014

Aug. 24, 2004

Accrued Payments

Research and development expense

$ 52,696,000

$ 38,331,000

$ 34,134,000

Cash balance

115,069,000

79,741,000

Milestone payment receivable

$ 57,500,000

Agreement commencement date

2015-05

Expected Cash Payment Payable

$ 1,500,000

Minimum Royalties Amount Payable

$ 100,000

Number of Warrants

18,939,394

MD Anderson Warrant [Member]

Accrued Payments

Number of Warrants

3,333,333

MD Anderson License and the Research and Development Agreement Member [Member]

Accrued Payments

Research and development service agreement aggregate quarterly payments

$ 15,000,000

Reimbursement of historical costs

$ 20,000,000

Accrued Payments

3,000,000

Aggregate potential benchmark payments

$ 36,500,000

CRADA Agreement [Member]

Accrued Payments

Obligations due under contract

$ 5,000,000

Quarterly payments under contract

2,500,000

2,500,000

The University of Texas MD Anderson Cancer Center and The Texas A & M University System

Accrued Payments

Milestone maximum payment

$ 4,500,000

Payments for Royalties

400,000

The University of Texas MD Anderson Cancer Center and The Texas A & M University System | Upon enrollment of the first patient in a multi-center pivotal clinical trial

Accrued Payments

Shares vested

50,222

ARES Trading License

Accrued Payments

Research and development expense

$ 100,000

License Agreement with the National Cancer Institute [Member]

Accrued Payments

payments under the Patent License

0

Ziop License Agreement With The National Cancer Institute [Member]

Accrued Payments

Minimum Royalties Amount Payable

$ 300,000

Description Of First Annual Royalty Payable

The first minimum annual royalty payment was paid during the year ending December 31, 2020

Description Of First Benchmark Payable

The first benchmark payment of $0.1 million will be due upon the initiation of the Company’s first sponsored Phase 1 clinical trial of a licensed product or licensed process in the field of use licensed under the Patent License.

Description Of option To terminate Agreement

The NCI may terminate or modify the Patent License in the event of a material breach,including if the Company does not meet certain milestones by certain dates, or upon certain insolvency events that remain uncured following the date that is 90 days following written notice of such breach or insolvency event.

Agreement termination, notice period

60 days

payments under the Patent License

500,000

1,000,000

Accrued Payments

0

$ 500,000

Ziop License Agreement With The National Cancer Institute [Member] | Performance Based Payments Member [Member]

Accrued Payments

Aggregate Benchmark Payments Payable

$ 4,300,000

Ziop License Agreement With The National Cancer Institute [Member] | One Time Benchmark Payments [Member]

Accrued Payments

Potential Benchmark Payments Payable

12,000,000

Ziop License Agreement With The National Cancer Institute [Member] | Post Marketing Approval [Member] | Performance Based Payments Member [Member]

Accrued Payments

Aggregate Benchmark Payments Payable

3,000,000

Ziop License Agreement With The National Cancer Institute [Member] | License [Member]

Accrued Payments

payments under the Patent License

600,000

Ziop License Agreement With The National Cancer Institute [Member] | licensed products [Member] | One Time Benchmark Payments [Member]

Accrued Payments

Maximum Sales Revenue On Which Benchmark Payments Payable

$ 1,000,000,000

Prepaid Expenses and Other Current Assets | MD Anderson License

Accrued Payments

Cash balance

8,100,000

Prepaid Expenses and Other Current Assets | Ziop License Agreement With The National Cancer Institute [Member]

Accrued Payments

Prepaid Royalties

300,000

Intrexon Corporation

Accrued Payments

Licensing fee

$ 115,000,000

Milestone payment receivable

$ 5

Upfront payment received

$ 57,500,000

Percentage of upfront fee Payable

50.00%

Maximum [Member] | MD Anderson License and the Research and Development Agreement Member [Member]

Accrued Payments

Research and development expense

$ 20,000,000

Warrants - Additional Informati

Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Sep. 12, 2019	Nov. 11, 2018	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of securities into which the class of warrant converted		18,939,394
Warrant Exercise Per share		$ 2.64
Fair Value Assumptions Expected volatility Rate Maximum				74.41%	85.00%	84.71%
Fair Value Assumptions Risk Free Interest Rate Maximum				1.68%	2.53%	3.06%
Fair Value Assumptions Expected Term1						6 years
Fair Value Assumptions Expected Dividend Rate				0.00%	0.00%	0.00%
Net Proceeds from Underwriting				$ 13,016	$ 6,085
Proceeds from private placement	$ 52,500
Non-cash inducement warrant expense			$ (60,751)		$ 60,751
MD Anderson Warrant [Member]
Number of securities into which the class of warrant converted				3,333,333
Warrant Exercise Per share				$ 0.001
Grant Date Fair Value of a warrant				$ 14,500
Warrant Expiry date				Dec. 31, 2026
Securities Purchase Agreement [Member]
Net Proceeds from Underwriting		$ 47,100		$ 47,100
Private Placement [Member]
Number of securities into which the class of warrant converted	17,803,031			18,939,394
Warrant Exercise Per share	$ 3.01			$ 3.01
Grant Date Fair Value of a warrant				$ 18,400
Fair Value Assumptions Expected volatility Rate Maximum				71.00%
Fair Value Assumptions Risk Free Interest Rate Maximum				2.99%
Fair Value Assumptions Expected Term1				5 years
Fair Value Assumptions Expected Dividend Rate				0.00%
Placement agent fees and other expenses	$ 1,100
Private Placement [Member] | New Warrants [Member]
Number of securities into which the class of warrant converted	17,803,031
Warrant Exercise Per share	$ 7
Non-cash inducement warrant expense	$ 60,800			$ 60,800

Significant Component of Deferr

Significant Component of Deferred Tax Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Net operating loss carryforwards	$ 147,004	$ 124,115
Deferred tax assets:
Start-up and organizational costs	25,909	30,480
Research and development credit carryforwards	37,183	35,130
Stock compensation	1,478	1,087
Capitalized acquisition costs	3,691	4,501
Lease liability	1,225	626
Depreciation	71	176
Other	135	1,186
Deferred Tax Assets Gross	216,696	197,301
Less valuation allowance	(215,513)	(196,696)
Total deferred tax assets	1,183	605
Deferred tax liabilities:
Right of use asset	(1,183)	(605)
Total deferred tax liabilities	(1,183)	(605)
Net deferred taxes	$ 0	$ 0

Reconciliation of Income Tax Ex

Reconciliation of Income Tax Expense (Benefit) (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal income tax at statutory rates	21.00%	21.00%	21.00%
State income tax, net of federal tax benefit	3.00%	3.00%	4.00%
Non-cash inducement warrant expense	0.00%	(11.00%)	0.00%
Research and development credits	3.00%	1.00%	2.00%
Stock compensation	(1.00%)	0.00%	(1.00%)
Research and development true-up	0.00%	0.00%	0.00%
Officers compensation	0.00%	0.00%	(1.00%)
Other	0.00%	(1.00%)	(2.00%)
Federal rate change	(2.00%)	0.00%	3.00%
Change in valuation allowance	(24.00%)	(13.00%)	(26.00%)
Effective tax rate	0.00%	0.00%	0.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 27, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2013
Income Taxes [Line Items]
Net operating loss carryforwards		$ 147,004	$ 124,115
Deferred tax assets operating loss carryforwards without expire date		220,000
Research and development credit carryforwards		$ 37,183	35,130
Net operating loss carryforwards, expiration date		2040
Uncertain Tax Positions Adjustment		$ 0	$ 0	$ 0
Increase (decrease) in deferred tax assets		18,800
Covid 19
Income Taxes [Line Items]
Relaxation of taxable income, percentage	30.00%
Relaxation of Adjusted taxable income, percentage	50.00%
Covid 19 | Qualified Improvement Property
Income Taxes [Line Items]
Eligible bonus percentage	100.00%
Estimated useful life	15
Research Tax Credit Carryforward
Income Taxes [Line Items]
Research and development credit carryforwards		37,000
Net Operating Loss Carryforwards
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets					$ (11,200)
General Business Credits
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets					$ (636)
Domestic Tax Authority
Income Taxes [Line Items]
Net operating loss carryforwards		$ 562,000
Net operating loss carryforwards, expiration date		2037
Federal and State
Income Taxes [Line Items]
Deferred tax assets operating loss carryforwards with expire date		$ 342,000
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carryforwards		$ 458,000

Preferred Stock and Stockhold_2

Preferred Stock and Stockholders' Equity (Deficit) - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Mar. 10, 2020	Feb. 05, 2020	Nov. 11, 2018	Jun. 29, 2016	Dec. 31, 2020	Dec. 31, 2019	Feb. 24, 2021	Feb. 24, 2020	Apr. 26, 2006
Equity [Line Items]
Shares of authorized capital stock									280,000,000
Common stock, shares authorized					250,000,000	250,000,000			250,000,000
Initial Public Offering of Common Stock			$ 0.001		$ 0.001	$ 0.001			$ 0.001
Preferred stock, shares authorized					30,000,000	30,000,000			30,000,000
Issuance of Common Stock to Underwriters					2,814,673
Net Proceeds from Underwriting					$ 13,016	$ 6,085
Sale of stock consideration received on transaction					$ 88,661
Number of securities into which the class of warrant converted			18,939,394
Warrant Exercise Price per share			$ 2.64
Warrant exercise, net of commissions and expenses			$ 47,100			$ 52,499
Common stock, shares outstanding					214,591,906	181,803,320
Common Stock, shares reserved for future issuance							31,115,329
Common Stock [Member]
Equity [Line Items]
Common stock, shares authorized								250,000,000
Issuance of Common Stock to Underwriters					2,814,673	1,271,274
Net Proceeds from Underwriting					$ 3	$ 1
Common stock, shares outstanding							214,667,023	214,667,023
Common Stock, shares reserved for future issuance								31,115,329
At The Market Offering [Member]
Equity [Line Items]
Issuance of Common Stock to Underwriters					2,814,673	1,271,274
Sale of stock consideration received on transaction					$ 13,000	$ 6,100
Series 1 Preferred Stock
Equity [Line Items]
Preferred stock, stated value					$ 1,200	$ 1,200
Intrexon Corporation/Precigen | Series 1 Preferred Stock
Equity [Line Items]
Issuance of common stock in licensing agreement (in shares)				100,000	11,415
Preferred stock, stated value				$ 1,200
Underwriting Agreement with Jefferies [Member]
Equity [Line Items]
Issuance of Common Stock to Underwriters	1,284,025	27,826,086
Underwriters Purchase Price		$ 3.055
Number of Days Option Exerciable		30 days
Net Proceeds from Underwriting	$ 3,900	$ 84,800
Underwriting Agreement with Jefferies [Member] | Maximum [Member]
Equity [Line Items]
Issuance of Common Stock to Underwriters		4,173,912
Underwriting Agreement [Member]
Equity [Line Items]
Issuance of Common Stock to Underwriters		27,826,086				1,271,274
Underwriters Purchase Price		$ 3.055
Sale of stock consideration received on transaction		$ 84,800			$ 13,000	$ 6,100
Issuance & sale of common stock in public offering price per share		$ 3.25
Underwriting Agreement [Member] | Maximum [Member]
Equity [Line Items]
Issuance of Common Stock to Underwriters		4,173,912
Underwriters Purchase Price		$ 3.055

Change in Derivative Liability

Change in Derivative Liability (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Beginning Balance	$ 0	$ 0	$ 2,424
Dividends	0	0	223
Change in fair value	0	0	(158)
Settlement of a related party relationship			(2,489)
Ending Balance	$ 0	$ 0	$ 0

Fair Value Assumptions Used in

Fair Value Assumptions Used in Probability Weighted Approach and Monte Carlo Simulation Model for Derivatives (Detail) - Series 1 Preferred Stock	12 Months Ended
	Dec. 31, 2018$ / shares
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Preferred stock conversion limit - percentage of outstanding common stock	19.90%
Preferred conversion floor price	$ 1
Measurement Input, Expected Dividend Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	0.00%
Minimum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	2.50%
Minimum [Member] | Measurement Input, Price Volatility [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	77.60%
Maximum [Member] | Measurement Input, Risk Free Interest Rate [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	3.13%
Maximum [Member] | Measurement Input, Price Volatility [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair Value Assumptions of Preferred Stock	82.40%

Stock Option Activity Under Sto

Stock Option Activity Under Stock Option Plan (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Shares
Beginning Balance	5,842,879	5,277,085	3,852,135
Granted	2,222,368	2,880,691	1,744,950
Exercised	(338,333)	(581,105)	(104,167)
Cancelled	(894,528)	(1,733,792)	(215,833)
Ending Balance	6,832,386	5,842,879	5,277,085
Options exercisable, at end of period	3,596,315	2,765,357
Options available for future grant	5,714,648
Weighted Average Exercise Price
Beginning Balance	$ 3.21	$ 4.24	$ 5.12
Granted	3.39	3.40	2.35
Exercised	2.01	3.30	2.35
Cancelled	4.22	4.21	5.72
Ending Balance	3.81	3.21	$ 4.24
Options exercisable, at end of period	$ 4.17	$ 4.39
Weighted Average Contractual Term (Years)
Outstanding, at end of period	7 years 11 months 8 days
Options exercisable, at end of period	6 years 10 months 24 days	6 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding, at end of period	$ 812
Options exercisable, at end of period	$ 598	$ 3,603

Summary of Non-Vested Restricte

Summary of Non-Vested Restricted Stock (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Shares
Granted	805,900	1,519,766
Unvested Restricted Common Stock
Number of Shares
Beginning Balance	939,676	682,110	1,808,559
Granted	805,900	1,519,766	150,321
Vested	(764,360)	(1,187,601)	(1,005,337)
Cancelled	(194,897)	(74,599)	(271,433)
Ending Balance	786,319	939,676	682,110
Weighted Average Grant Date Fair Value
Beginning Balance	$ 2.93	$ 3.47	$ 5.74
Granted	3.75	2.44	1.87
Vested	3.51	2.82	6.62
Cancelled	3.44	3.41	5
Ending Balance	$ 3.08	$ 2.93	$ 3.47

Stock Option Plan - Additional

Stock Option Plan - Additional information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Nov. 21, 2019	Aug. 19, 2019	Jul. 22, 2019	Jan. 31, 2019	Sep. 30, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 24, 2021	Dec. 31, 2017	Apr. 26, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance									31,115,329
Outstanding options issued						6,832,386	5,842,879	5,277,085		3,852,135
Proceeds from stock options exercised						$ 442	$ 1,219	$ 240
Total intrinsic value of options						$ 300	$ 1,100	$ 100
Stock options, granted						2,222,368	2,880,691	1,744,950
Stock options granted exercise price						$ 3.39	$ 3.40	$ 2.35
Share-based payment award granted						805,900	1,519,766
Options available for future grant						5,714,648
Common stock, shares authorized						250,000,000	250,000,000				250,000,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of shares of restricted common stock							225,339	514,349
restricted stock in lieu				446,428
Restricted Stock | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of shares of restricted common stock, price per share							$ 4.72	$ 4.41
Restricted Stock | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Repurchase of shares of restricted common stock, price per share							$ 2.24	$ 1.70
Restricted Stock | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award granted						805,900	1,519,766
Unvested Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs related to non-vested restricted stock outstanding						$ 7,300
Expected recognition period						1 year 9 months 10 days
Unvested Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected recognition period						1 year 4 months 2 days
Share-based payment award granted						805,900	1,519,766	150,321
Unrecognized stock-based compensation expense related to non-vested restricted stock arrangements						$ 1,800
the "2012 Plan"
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance						14,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized						21
Options available for future grant						22,066,275
Share Based Payment Award Shares Registered Due to Proximity On Authorized Shares						5,750,000
the "2012 Plan" | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance						5,659,018
the "2012 Plan" | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued						57,331,551
the "2012 Plan" | Director | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued						1,039,231
the "2012 Plan" | Consultants | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued						60,000
Outside 2012 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding options issued						588,333
Stock options, granted	65,000	65,000	400,000		500,000
Stock options granted exercise price	$ 4.59	$ 5.18	$ 5.60		$ 6.16
Share Based compensation arrangement by share based payment award options grants grant date fair value	$ 193	$ 231	$ 1,500		$ 2,200
Options available for future grant						1,066,275
the "2020 Plan" | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance						1,173,368

Employee Benefit Plan - Additio

Employee Benefit Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Defined benefit plan contributions by employer	$ 538	$ 404	$ 329

Joint Venture - Additional Inf

Joint Venture - Additional Information (Detail) - USD ($) $ in Millions	Jul. 05, 2019	Dec. 31, 2020	Dec. 31, 2019	Jan. 03, 2019
Subsidiary or Equity Method Investee [Line Items]
Common stock, shares issued		214,591,906	181,803,320
Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Equity method investments		$ 0
Ziopharm [Member] | Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Equity interest in affilated entity	50.00%
Tri Arm [Member] | Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Equity interest in affilated entity	50.00%
Tri Arm [Member] | License Agreement Terms [Member] | Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Milestone payment made	$ 10
Conditional milestone amount payable	$ 25
Share Subscription Agreement [Member] | Ziopharm [Member] | Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Common stock, shares issued				10,000,000
Share Subscription Agreement [Member] | Tri Arm [Member] | Eden Bio Cell [Member]
Subsidiary or Equity Method Investee [Line Items]
Common stock, shares issued				10,000,000

Selected Quarterly Informatio_3

Selected Quarterly Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 0	$ 0	$ 0	$ 0							$ 146
Total operating expenses	22,774	20,321	18,606	18,660	$ 16,036	$ 13,448	$ 14,753	$ 13,621
Loss from operations	(22,774)	(20,321)	(18,606)	(18,660)	(16,036)	(13,448)	(14,753)	(13,621)	$ (80,361)	$ (57,858)	(53,906)
Non-cash inducement warrant expense						(60,751)				60,751
Net income (loss) applicable to common shareholders	$ (22,772)	$ (20,315)	$ (18,596)	$ (18,293)	$ (15,746)	$ (73,996)	$ (14,620)	$ (13,434)	$ (79,976)	$ (117,796)	$ (53,117)
Net income (loss) per share, basic	$ (0.11)	$ (0.10)	$ (0.09)	$ (0.09)	$ (0.09)	$ (0.43)	$ (0.09)	$ (0.08)	$ (0.38)	$ (0.70)	$ 0.96
Net income (loss) per share, diluted	$ (0.11)	$ (0.10)	$ (0.09)	$ (0.09)	$ (0.09)	$ (0.43)	$ (0.09)	$ (0.08)	$ (0.38)	$ (0.70)	$ 0.96