Iovance Biotherapeutics (IOVA) 10-Q 5 May 22 2022 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2022	Apr. 25, 2022
Document And Entity Information [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36860
Entity Registrant Name	IOVANCE BIOTHERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	75-3254381
Entity Address, Address Line One	825 Industrial Road, Suite 400
Entity Address, City or Town	San Carlos
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94070
City Area Code	650
Local Phone Number	260-7120
Title of 12(b) Security	Common Stock, par value $0.000041666
Trading Symbol	IOVA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		157,168,321
Entity Central Index Key	0001425205
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current Assets
Cash and cash equivalents	$ 92,360	$ 78,229
Short-term investments	389,829	426,181
Prepaid expenses and other assets	7,779	3,546
Total Current Assets	489,968	507,956
Property and equipment, net	102,757	100,938
Operating lease right-of-use assets	73,475	68,983
Long-term investments	27,701	91,588
Restricted cash	6,084	6,084
Long-term assets	1,266	1,784
Total Assets	701,251	777,333
Current Liabilities
Accounts payable	20,454	27,377
Accrued expenses	48,911	56,766
Operating lease liabilities	7,710	5,057
Total Current Liabilities	77,075	89,200
Non-Current Liabilities
Operating lease liabilities - noncurrent	71,184	65,474
Long-term note payable	1,000	1,000
Total Non-Current Liabilities	72,184	66,474
Total Liabilities	149,259	155,674
Commitments and contingencies
Stockholders' Equity
Common stock, $0.000041666 par value; 300,000,000 shares authorized, 157,168,321 and 157,004,742 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	7	7
Accumulated other comprehensive loss	(2,343)	(601)
Additional paid-in capital	1,818,377	1,794,695
Accumulated deficit	(1,264,052)	(1,172,445)
Total Stockholders' Equity	551,992	621,659
Total Liabilities and Stockholders' Equity	701,251	777,333
Series A Convertible Preferred Stock
Stockholders' Equity
Preferred stock, Value	0	0
Series B Convertible Preferred Stock
Stockholders' Equity
Preferred stock, Value	$ 3	$ 3

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2022	Dec. 31, 2021
Common stock, par or stated value per share	$ 0.000041666	$ 0.000041666
Common stock, shares authorized	300,000,000	300,000,000
Common Stock, Shares, Issued	157,168,321	157,004,742
Common Stock, Shares, Outstanding	157,168,321	157,004,742
Series A Convertible Preferred Stock
Preferred stock, par or stated value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	17,000	17,000
Preferred Stock, Shares Issued	194	194
Preferred stock, shares outstanding	194	194
Series B Convertible Preferred Stock
Preferred stock, par or stated value per share	$ 0.001	$ 0.001
Preferred stock, shares authorized	11,500,000	11,500,000
Preferred Stock, Shares Issued	2,842,158	2,842,158
Preferred stock, shares outstanding	2,842,158	2,842,158

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Costs and expenses
Research and development expenses	$ 68,300	$ 55,949
General and administrative expenses	23,413	19,621
Total costs and expenses	91,713	75,570
Loss from operations	(91,713)	(75,570)
Other income
Interest income, net	106	121
Net Loss	$ (91,607)	$ (75,449)
Net Loss Per Share of Common Stock, Basic	$ (0.58)	$ (0.51)
Net Loss Per Share of Common Stock, Diluted	$ (0.58)	$ (0.51)
Weighted Average Shares of Common Stock Outstanding, Basic	157,113	147,370
Weighted Average Shares of Common Stock Outstanding, Diluted	157,113	147,370

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Condensed Consolidated Statements of Comprehensive Loss
Net Loss	$ (91,607)	$ (75,449)
Other comprehensive (loss) income:
Unrealized (loss) income on investments	(1,742)	77
Comprehensive Loss	$ (93,349)	$ (75,372)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Series A Convertible Preferred StockPreferred Stock	Series B Convertible Preferred StockPreferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Comprehensive Income (Loss)	Accumulated Deficit	Total
Beginning Balance at Dec. 31, 2020		$ 4	$ 6	$ 1,486,662	$ 19	$ (830,193)	$ 656,498
Beginning Balance (in Shares) at Dec. 31, 2020	194	3,581,119	146,874,917
Stock-based compensation expense				16,941			16,941
Common stock issued upon exercise of stock options				6,479			6,479
Common stock issued upon exercise of stock options (in shares)			423,178
Common stock sold in public offering, net of offering costs				42,885			42,885
Common stock sold in public offering, net of offering costs (in shares)			1,278,243
Common stock issued from preferred stock conversion		$ (1)		1
Common stock issued from preferred stock conversion (in Shares)		(738,961)	738,961
Unrealized (loss) income on investments					77		77
Net loss						(75,449)	(75,449)
Ending Balance at Mar. 31, 2021		$ 3	$ 6	1,552,968	96	(905,642)	647,431
Ending Balance (in Shares) at Mar. 31, 2021	194	2,842,158	149,315,299
Beginning Balance at Dec. 31, 2021		$ 3	$ 7	1,794,695	(601)	(1,172,445)	621,659
Beginning Balance (in Shares) at Dec. 31, 2021	194	2,842,158	157,004,742
Stock-based compensation expense				22,265			22,265
Common stock issued upon exercise of stock options				1,417			1,417
Common stock issued upon exercise of stock options (in shares)			163,579
Unrealized (loss) income on investments					(1,742)		(1,742)
Net loss						(91,607)	(91,607)
Ending Balance at Mar. 31, 2022		$ 3	$ 7	$ 1,818,377	$ (2,343)	$ (1,264,052)	$ 551,992
Ending Balance (in Shares) at Mar. 31, 2022	194	2,842,158	157,168,321

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash Flows from Operating Activities
Net loss	$ (91,607)	$ (75,449)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	22,265	16,941
Amortization of right of use asset	3,181	2,402
Depreciation and amortization	1,797	372
Accretion (amortization) of discounts and premiums on investments	541	2,066
Loss on write-off of fixed assets	314	0
Changes in assets and liabilities:
Prepaid expenses, other assets and long-term assets	(3,715)	(4,067)
Operating lease liabilities	690	(1,374)
Accounts payable	(2,104)	(15)
Accrued expenses and other liabilities	(5,164)	(3,267)
Net cash used in operating activities	(73,802)	(62,391)
Cash Flows from Investing Activities
Maturities of investments	143,508	158,286
Purchase of investments	(45,552)	(70,370)
Purchase of property and equipment	(11,440)	(10,705)
Net cash provided by investing activities	86,516	77,211
Cash Flows from Financing Activities
Proceeds from the issuance of common stock upon exercise of options	1,417	6,479
Proceeds from the issuance of common stock, net	0	42,885
Proceeds from the issuance of debt	0	1,000
Net cash provided by financing activities	1,417	50,364
Net increase in cash, cash equivalents and restricted cash	14,131	65,184
Cash, Cash Equivalents and Restricted Cash Beginning of Period	84,313	72,854
Cash, Cash Equivalents and Restricted Cash End of Period	98,444	138,038
Supplemental disclosure of non-cash investing and financing activities:
Net unrealized (loss) gain on short-term investments	(1,742)	77
Acquisition of property and equipment included in accounts payable and accrued expenses	4,900	8,352
Conversion of convertible preferred stock to common stock	0	(1)
Lease liabilities arising from obtaining right-of-use asset from lease modifications	$ 7,673	$ 0

GENERAL ORGANIZATION, BUSINESS

GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY	3 Months Ended
	Mar. 31, 2022
GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY
GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY	NOTE 1. GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY General Organization and Business Iovance Biotherapeutics, Inc. (the “Company”) is a clinical-stage biopharmaceutical company pioneering a transformational approach to cure cancer by harnessing the human immune system’s ability to recognize and destroy diverse cancer cells in each patient. Tumor infiltrating lymphocyte (“TIL”) therapy is an autologous cell therapy platform technology that was originally developed by the National Cancer Institute (“NCI”), which conducted initial clinical trials in diseases such as metastatic melanoma and cervical cancer, as well as non-small cell lung cancer. The Company’s mission is to be the global leader in innovating, developing and delivering TIL therapy for patients with cancer. The Company has developed a new, shorter proprietary TIL manufacturing process known as Generation 2 (“Gen 2”), which yields a cryopreserved TIL product. This centralized, proprietary, and scalable manufacturing method is being investigated in multiple indications. The Company’s lead product candidates include lifileucel for metastatic melanoma and metastatic cervical cancer, as well as LN-145 for metastatic non-small cell lung cancer (“NSCLC”). In addition, the Company is investigating the effectiveness and safety of combinations of TIL therapy with immune checkpoint inhibitors (“ICI”), in metastatic melanoma, cervical cancer, NSCLC, and head and neck squamous cell carcinoma (“HNSCC”). The Company is investigating peripheral blood lymphocyte (“PBL”) therapy for patients with relapsed or refractory chronic lymphocytic leukemia (“CLL”) and small lymphocytic lymphoma (“SLL”) through its sponsored trials. The Company is also investigating the potential for TIL therapy in other oncology indications through academic collaborations with leading cancer research centers. On June 1, 2017, the Company reincorporated from a Nevada corporation to a Delaware corporation. Basis of Presentation of Unaudited Condensed Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements of the Company for the three months ended March 31, 2022 and 2021 have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information and pursuant to the requirements for reporting on Form 10-Q and Regulation S-X. Accordingly, they do not include all the information and footnotes required by GAAP for audited financial statements. However, such information reflects all adjustments (consisting solely of normal recurring adjustments), which are, in the opinion of management, necessary for the fair presentation of the Company's financial position and results of operations. Results shown for interim periods are not necessarily indicative of the results that may be expected for the year ended December 31, 2022 or for any other period. The condensed consolidated balance sheet as of December 31, 2021 was derived from the audited consolidated financial statements included in the Company's Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on February 24, 2022. These interim financial statements should be read in conjunction with that report. Certain prior period amounts reported in our condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period presentation. Liquidity The Company is currently engaged in the development of therapeutics to fight cancer, specifically solid tumors. The Company currently does not have any commercial products and has not yet generated any revenues from its business, nor does the Company currently anticipate that it will generate any significant revenues from the sale or licensing of any of its product candidates during the twelve months from the date these financial statements are issued. The Company has incurred a net loss of $91.6 million for the three months ended March 31, 2022 and used $73.8 The Company expects to continue its research and development activities, increase pre-commercial activities and complete construction of the remaining tenant improvements for the Iovance Cell Therapy Center (the “ i CTC”), which are expected to increase the amount of cash used during the remainder of 2022 and beyond. Specifically, the Company expects continued spending on its current and planned clinical trials, continued expansion of manufacturing activities, higher payroll expenses as the Company increases its professional and scientific staff and continuation of pre-commercial activities. Based on the funds the Company has available as of the date these financial statements are issued, the Company believes that it has sufficient capital to fund its anticipated operating expenses and capital expenditures as planned for at least the next twelve months from the date these financial statements are issued. Concentrations of Risk The Company is subject to credit risk from its portfolio of cash, cash equivalents and investments. Under its investment policy, the Company limits amounts invested in securities by credit rating, maturity, industry group, investment type and issuer, except for securities issued by the U.S. government. The Company does not believe it is exposed to any significant concentrations of credit risk from these financial instruments. The goals of its investment policy are safety and preservation of principal, diversification of risk, and liquidity of investments sufficient to meet cash flow requirements.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2022
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Cash, Cash Equivalents, and Investments The Company’s cash and cash equivalents include short-term investments with original maturities of three months or less when purchased. The Company's investments are classified as “available-for-sale.” The Company includes these investments in current assets or non-current assets in the Condensed Consolidated Balance Sheets based on the length of maturity from the reporting date and carries them at fair value. Unrealized gains and losses on available-for-sale securities are recorded in accumulated other comprehensive loss. Impairment losses related to credit losses (if any) are recorded as an allowance for credit losses with an offsetting entry to Interest income, net. No impairment losses related to credit losses were recognized for the three months ended March 31, 2022 and 2021. The cost of debt securities is adjusted for the amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in Interest income, net in the Condensed Consolidated Statements of Operations. Gains and losses on securities sold are recorded based on the specific identification method and are included in Interest income, net in the Condensed Consolidated Statements of Operations. The Company has not incurred any realized gains or losses from sales of securities to date. The Company’s investment policy limits investments to certain types of instruments such as certificates of deposit, money market instruments, obligations issued by the U.S. government and U.S. government agencies as well as corporate debt securities and commercial paper, and places restrictions on maturities and concentration by type and issuer, except for securities issued by the U.S. government. Restricted Cash The Company maintains a required minimum balance in a segregated bank account in connection with three letters of credit, one for $5.45 million for the benefit of the landlord for the i The following table provides a reconciliation of cash, cash equivalents, and restricted cash, reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2022 ​ 2021 Cash and cash equivalents ​ $ 92,360 ​ $ 131,954 Restricted cash ​ 6,084 ​ 6,084 Total cash, cash equivalents and restricted cash ​ $ 98,444 ​ $ 138,038 ​ Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the sum of the weighted average number of shares of common stock outstanding and the dilutive common stock equivalents outstanding during the period. The Company’s potentially dilutive common stock equivalent shares, which include incremental common shares issuable upon (i) the exercise of outstanding stock options, (ii) purchases though the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), (iii) vesting of restricted stock units, and (iv) conversion of preferred stock, are only included in the calculation of diluted net loss per share when their effect is dilutive. As of March 31, 2022 and 2021, the following outstanding common stock equivalents have been excluded from the calculation of net loss per share because their impact would be anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ 2022 2021 Stock options ​ 14,101,526 15,419,226 Employee Stock Purchase Plan ​ 86,448 ​ 55,963 Restricted stock units ​ 3,095,177 ​ — Series A Convertible Preferred Stock* ​ 97,000 ​ 97,000 Series B Convertible Preferred Stock* ​ 2,842,158 2,842,158 ​ ​ 20,222,309 18,414,347 * on an as-converted basis The dilutive effect of potentially dilutive securities would be reflected in diluted earnings per common share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of the Company's common stock could result in a greater dilutive effect from potentially dilutive securities. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant items subject to such estimates and assumptions include assumptions made in the fair value of equity awards and related stock-based compensation, assumptions used in measuring operating right-of-use assets and operating lease liabilities, accounting for potential liabilities, including estimates inherent in accruals related to clinical trials, and the realizability of the Company’s deferred tax assets . Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Iovance Biotherapeutics, Inc. and its wholly-owned subsidiaries, Iovance Biotherapeutics Manufacturing LLC, Iovance Biotherapeutics GmbH, and Iovance Biotherapeutics B.V . All intercompany accounts and transactions have been eliminated. The U.S. dollar is the functional currency for all the Company's consolidated operations. Leases The Company determines if an arrangement includes a lease at inception and thereafter, if modified. Operating leases are included in its Condensed Consolidated Balance Sheets as Operating lease right-of-use assets and Operating lease liabilities as of March 31, 2022 and December 31, 2021. Operating lease right-of-use assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date or modification date based on the present value of lease payments over the lease term. In determining the net present value of lease payments, the Company uses an estimated incremental borrowing rate that is applicable to the Company based on the information available at the later of the lease commencement or modification date. The operating lease right-of-use assets also include any lease payments made less lease incentives. The Company’s leases may include options to extend or terminate the lease, which is considered in the lease term when it is reasonably certain that the Company will exercise any such options. Lease expense is recognized on a straight-line basis over the expected lease term and recorded in costs and expenses in the Condensed Consolidated Statements of Operations. The Company has elected not to apply the recognition requirements of Accounting Standards Update (“ASU”) No. 2016-02 and No. 2018-10 (together “Topic 842”) for short-term leases. For lease agreements entered into by the Company that include lease and non-lease components, such components are generally accounted for separately. Stock-Based Compensation The Company periodically grants stock options to employees and non-employees as compensation for services rendered. The Company accounts for all stock-based payment awards made to employees, including the employee stock purchase plans, and non-employees in accordance with the authoritative guidance provided by the Financial Accounting Standards Board (“FASB”) where the value of the award is measured on the date of grant and recognized over the vesting period. Forfeitures are recognized in the period in which they occur. The Company accounts for stock option grants to non-employees in a similar manner as stock option grants to employees except for the term used in the grant date fair value, therefore no longer requiring a re-measurement at the then-current fair values at each reporting date until the shares underlying the options have vested. The non-employee awards that contain a performance condition that affects the quantity or other terms of the award are measured based on the outcome that is probable. The fair value of the Company's common stock option grants is estimated using a Black-Scholes option pricing model, which uses certain assumptions related to risk-free interest rates, expected volatility, expected term of the common stock options, and future dividends. The stock-based compensation expense is recorded based upon the value derived from the Black-Scholes option pricing model. The assumptions used in the Black-Scholes option pricing model could affect compensation expense recorded in future periods. The Company issues restricted stock units (“RSUs”) from time to time as part of its equity incentive plans. The Company measures the compensation cost with respect to RSUs issued to employees based upon the estimated fair value of the equity instruments at the date of the grant, which is recognized as an expense over the period during which an employee is required to provide services in exchange for the awards. The fair value of RSUs is based on the closing price of the Company’s common stock on the grant date. Accrued Research and Development Costs Research and development costs are expensed as incurred. Clinical development costs compose a significant component of research and development costs. The Company has a history of contracting with third parties, including contract research organizations (“CROs”), independent clinical investigators, and contract manufacturing organizations (“CMOs”) that perform various clinical trial activities on the Company’s behalf in connection with the ongoing development of the Company’s product candidates. The financial terms of these contracts are subject to negotiations and may vary from contract to contract and may result in uneven payment flow. The Company accrues and expenses costs for clinical trial activities performed by third parties based upon estimates of work completed to date for each clinical trial in accordance with agreements established with CROs, hospitals, and clinical investigators. Accruals for CROs and CMOs are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs and other outside service providers. The Company determines its estimates through discussions with internal clinical stakeholders and outside service providers as to the progress or stage of completion of clinical trials or services and the contracted fee to be paid for such services. Included in the Company’s clinical development costs are investigator costs, which are costs associated with treatments administered at clinical sites as required under each clinical study protocol. The Company’s estimates for clinical investigator costs and timing of expense recognition will depend on a number of factors that include, but are not limited to, (i) the overall number of patients that enroll in the trial at each individual site, (ii) the length of study enrollment period, (iii) discontinuation and completion rates of patients, (iv) duration of patient safety follow-ups, (v) the number of sites included in the clinical trial, and (vi) the contracted fee of each participating site for patient treatment while on study, which can vary greatly for several reasons including, but not limited to, geographic region, medical center or physician costs, and overhead costs. In addition, the Company’s estimates for per patient trial costs will vary based on a number of factors that include, but are not limited to, the extent of additional treatments that may be administered by investigators as a result of patient health status, recoverability of patient costs through insurance carriers of patients, and unanticipated cost of injuries incurred as a result of the study treatment. The Company accrues for estimated expenses resulting from obligations under investigator site agreements as the timing of payments does not always timely align with the periods over which the treatments are administered by the clinical investigators. These estimates are typically based on contracted amounts, patient visit data, discussions with internal clinical stakeholders and outside service providers, and historical look-back analysis of actual payments made to date. The Company makes judgements and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO or other outside service provider, the payments are recorded within prepaid expenses and other current assets in the Condensed Consolidated Balance Sheets and subsequently recognized as research and development expense in the Condensed Consolidated Statements of Operations when the associated services have been performed. As actual costs become known, the Company adjusts its estimates, liabilities and assets. Inputs used in the determination of estimates discussed above may vary from actual, which will result in adjustments to research and development expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect its results of operations. The Company’s historical estimates have not been materially different from actual amounts recorded. Segment Reporting The Company operates in one segment, focused on developing and commercializing therapies using autologous TIL for the treatment of metastatic melanoma and other solid tumor cancers.

CASH EQUIVALENTS, INVESTMENTS A

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2022
CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS
CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS	NOTE 3. CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS The amortized cost, fair value measurements, and fair value of cash equivalents and investments as of March 31, 2022 and December 31, 2021 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ ​ ​ As of March 31, 2022 Cost Gains Losses Fair Value U.S. treasury securities ​ $ 248,546 ​ $ — ​ $ (2,062) ​ $ 246,484 U.S. government agency securities ​ 5,067 ​ — ​ (21) ​ 5,046 Corporate securities ​ ​ 34,408 ​ ​ — ​ ​ (79) ​ ​ 34,329 Commercial paper ​ ​ 158,276 ​ ​ 1 ​ ​ (182) ​ ​ 158,095 Money market funds ​ ​ 45,249 ​ ​ — ​ ​ — ​ ​ 45,249 Total investments ​ $ 491,546 ​ $ 1 ​ $ (2,344) ​ $ 489,203 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ ​ ​ As of December 31, 2021 Cost Gains Losses Fair Value U.S. treasury securities ​ $ 247,287 ​ $ — ​ $ (520) ​ $ 246,767 U.S. government agency securities ​ 5,104 ​ — ​ (7) ​ 5,097 Corporate securities ​ ​ 35,627 ​ ​ — ​ ​ (39) ​ ​ 35,588 Commercial paper ​ ​ 235,352 ​ ​ 10 ​ ​ (46) ​ ​ 235,316 Money market funds ​ ​ 56,250 ​ ​ — ​ ​ — ​ ​ 56,250 Total investments ​ $ 579,620 ​ $ 10 ​ $ (612) ​ $ 579,018 ​ The fair value of cash equivalents and investments as of March 31, 2022 and December 31, 2021 are classified as follows in the Company’s Consolidated Balance Sheets (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, Classified as: ​ 2022 2021 Cash equivalents ​ $ 71,673 ​ $ 61,249 Short-term investments ​ ​ 389,829 ​ ​ 426,181 Long-term investments ​ ​ 27,701 ​ ​ 91,588 Total investments ​ $ 489,203 ​ $ 579,018 ​ Cash equivalents in the tables above exclude cash demand deposits of $20.7 Unrealized gains and losses are included in accumulated other comprehensive loss, and as of no unrealized losses on available-for-sale securities have resulted from credit risk. All available-for-sale securities held as of had contractual maturities of less than two years. No available-for-sale securities held as of the periods presented have been in a continuous unrealized loss position for more than 12 months. The Company determined that it has the ability and intent to hold all marketable securities that have been in a continuous loss position until maturity or recovery. To date, the Company has not recorded any impairment charges on its marketable securities. The following table summarizes the Company’s cash equivalents and available-for-sale investments by contractual maturity (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ ​ Amortized Cost Fair Value Within one year ​ $ 463,385 ​ $ 461,502 One year to two years ​ ​ 28,161 ​ ​ 27,701 Total investments ​ $ 491,546 ​ $ 489,203 ​ ​ Recurring Fair Value Measurements ​ As of March 31, 2022 and December 31, 2021, the fair value of the Company’s financial assets that are measured at fair value on a recurring basis, which consist of cash equivalents and short-term and long-term investments classified as available-for-sale securities, are categorized in the table below based upon the lowest level of significant input to the valuations (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets at Fair Value as of March 31, 2022 ​ Level 1 Level 2 Level 3 Total U.S. treasury securities ​ $ 246,484 ​ $ — ​ $ — ​ $ 246,484 U.S. government agency securities ​ — ​ 5,046 ​ — ​ 5,046 Corporate securities ​ ​ — ​ ​ 34,329 ​ ​ — ​ ​ 34,329 Commercial paper ​ ​ — ​ ​ 158,095 ​ ​ — ​ ​ 158,095 Money market funds ​ ​ 45,249 ​ ​ — ​ ​ — ​ ​ 45,249 Total ​ $ 291,733 ​ $ 197,470 ​ $ — ​ $ 489,203 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets at Fair Value as of December 31, 2021 ​ Level 1 Level 2 Level 3 Total U.S. treasury securities ​ $ 246,767 ​ $ — ​ $ — ​ $ 246,767 U.S. government agency securities ​ — ​ 5,097 ​ — ​ 5,097 Corporate securities ​ ​ — ​ ​ 35,588 ​ ​ — ​ ​ 35,588 Commercial paper ​ ​ — ​ ​ 235,316 ​ ​ — ​ ​ 235,316 Money market funds ​ ​ 56,250 ​ ​ — ​ ​ — ​ ​ 56,250 Total ​ $ 303,017 ​ $ 276,001 ​ $ — ​ $ 579,018 ​ Level 2 assets consist of commercial paper and government agency securities. Level 2 inputs for the valuations are limited to quoted prices for similar assets or liabilities in active markets and inputs other than quoted prices that are observable for the asset.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	3 Months Ended
	Mar. 31, 2022
PROPERTY AND EQUIPMENT, NET
PROPERTY AND EQUIPMENT, NET	NOTE 4. PROPERTY AND EQUIPMENT, NET Property and equipment, net consists of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2022 2021 Leasehold improvements ​ $ 65,767 ​ $ 57,817 Lab, process, and validation equipment ​ ​ 9,173 ​ ​ 8,686 Utility equipment ​ 4,179 ​ 4,179 Office furniture and equipment ​ 2,136 ​ 1,244 Computer software ​ ​ 6,264 ​ ​ 1,163 Computer equipment ​ 674 ​ 674 Machinery and equipment ​ ​ 82 ​ ​ 82 Construction in progress ​ 23,732 ​ 35,782 Total Property and equipment, cost ​ 112,007 ​ 109,627 Less: Accumulated depreciation and amortization ​ (9,250) ​ (8,689) Property and equipment, net ​ $ 102,757 ​ $ 100,938 ​ Depreciation expense for the three months ended March 31, 2022 and 2021, was $1.8 million, respectively.

ACCRUED EXPENSES

ACCRUED EXPENSES	3 Months Ended
	Mar. 31, 2022
ACCRUED EXPENSES
ACCRUED EXPENSES	NOTE 5. ACCRUED EXPENSES Accrued expenses consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2022 2021 Accrued payroll and employee related expenses ​ $ 18,204 ​ $ 21,513 Clinical related ​ ​ 17,910 ​ ​ 18,167 Manufacturing related ​ 6,295 ​ 6,566 Facilities related ​ ​ 2,077 ​ ​ 4,857 Legal and related services ​ 1,654 ​ 1,907 Other accrued expenses ​ 2,771 ​ 3,756 Total accrued expenses ​ $ 48,911 ​ $ 56,766 ​

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2022
STOCKHOLDERS' EQUITY
STOCKHOLDERS' EQUITY	NOTE 6. STOCKHOLDERS’ EQUITY Common Stock The Company’s certificate of incorporation, as amended, authorizes the issuance of up to 300,000,000 shares of the Company’s common stock, par value $0.000041666. As of March 31, 2022, 157,168,321 shares of the Company’s common stock were issued and outstanding . At the Market Offering Program On February 8, 2021, the Company entered into an Open Market Sale Agreement (the “Sales Agreement”) with Jefferies LLC (“Jefferies”) with respect to an “at the market” offering program, under which the Company may, from time to time, in its sole discretion, issue and sell through Jefferies, acting as sales agent, up to $350.0 million of shares of the Company’s common stock (the “Common Shares”). The issuance and sale, if any, of the Common Shares by the Company under the Sales Agreement will be made pursuant to a prospectus supplement, dated February 8, 2021, to the Company’s Registration Statement on Form S-3ASR, which became effective immediately upon filing with the Securities and Exchange Commission on May 27, 2020. Pursuant to the Sales Agreement, Jefferies may sell the Common Shares by any method permitted by law deemed to be an “at the market” offering as defined in Rule 415 of the Securities Act of 1933, as amended. Jefferies will use commercially reasonable efforts consistent with its normal trading and sales practices to sell the Common Shares from time to time, based upon instructions from the Company (including any price or size limits or other customary parameters or conditions the Company may impose). The Company will pay Jefferies a commission of up to 3.0% of the gross sales proceeds of any Common Shares sold through Jefferies under the Sales Agreement. The Company is not obligated to make any sales of Common Shares under the Sales Agreement. The offering of Common Shares pursuant to the Sales Agreement will terminate upon the earlier to occur of (i) the issuance and sale, through Jefferies, of all Common Shares subject to the Sales Agreement and (ii) termination of the Sales Agreement in accordance with its terms. No sales were made pursuant to the Sales Agreement during the three months ended March 31, 2022. For the three months ended March 31, 2021, the Company received approximately $42.9 million in net proceeds, net of offering costs, through the sale of 1,278,243 shares of its common stock through the Sales Agreement at a weighted average price per share of $34.67. Preferred Stock The Company’s certificate of incorporation authorizes the issuance of up to 50,000,000 shares of “blank check” preferred stock. As of March 31, 2022, 17,000 shares were designated as Series A Convertible Preferred Stock (“Series A Convertible Preferred Stock”) and 11,500,000 shares were designated as Series B Convertible Preferred Stock (“Series B Convertible Preferred Stock”). Series A Convertible Preferred Stock A total of 17,000 shares of Series A Convertible Preferred Stock have been authorized for issuance under the Company’s Certificate of Designation of Preferences and Rights of Series A Convertible Preferred Stock. The shares of Series A Convertible Preferred Stock have a stated value of $1,000 per share and are initially convertible into shares of common stock at a price of $2.00 per share, subject to adjustment. Each share of Series A Preferred Stock is initially convertible into 500 shares of common stock. The Series A Convertible Preferred Stock may, at the option of each investor, be converted into fully paid and non-assessable shares of common stock. The holders of shares of Series A Convertible Preferred Stock do not have the right to vote on matters that come before the Company’s stockholders. In the event of any dissolution or winding up of the Company, proceeds shall be paid pari passu among the holders of common stock and preferred stock, pro rata based on the number of shares held by each holder. The Company may not declare, pay, or set aside any dividends on shares of capital stock of the Company (other than dividends on shares of common stock payable in shares of common stock) unless the holders of the Series A Convertible Preferred Stock shall first receive an equal dividend on each outstanding share of Series A Convertible Preferred Stock. No shares of Series A Convertible Preferred Stock were converted during the three months ended March 31, 2022 or 2021. As of March 31, 2022, and December 31, 2021, 194 shares of Series A Convertible Preferred Stock (that are convertible into 97,000 shares of common stock) remained outstanding. Series B Convertible Preferred Stock A total of 11,500,000 shares of Series B Convertible Preferred Stock are authorized for issuance under the Company’s Series B Certificate of Designation of Rights, Preferences and Privileges of Series B Convertible Preferred Stock. The shares of Series B Convertible Preferred Stock have a stated value of $4.75 per share and are convertible into shares of the Company’s common stock at an initial conversion price of $4.75 per share. Each share of Series B Preferred Stock is initially convertible into 1 share of common stock. The Series B Convertible Preferred Stock may, at the option of each investor, be converted into fully paid and non-assessable shares of common stock. The holders of shares of Series B Convertible Preferred Stock do not have the right to vote on matters that come before the Company's stockholders. In the event of any dissolution or winding up of the Company, proceeds shall be paid pari passu among the holders of common stock and preferred stock, pro rata based on the number of shares held by each holder. Holders of Series B Convertible Preferred Stock are entitled to dividends on an as-if-converted basis in the same form as any dividends actually paid on shares of the Series A Convertible Preferred Stock or the Company’s common stock. So long as any Series B Convertible Preferred Stock remains outstanding, the Company may not redeem, purchase, or otherwise acquire any material amount of the Series A Convertible Preferred Stock or any securities junior to the Series B Convertible Preferred Stock. During the three months ended March 31, 2022, no shares of Series B Convertible Preferred Stock were converted into shares of common stock. During the three months ended March 31, 2021, a total of 738,961 of Series B Convertible Preferred Stock were converted into 738,961 shares of common stock. As of March 31, 2022, and December 31, 2021, 2,842,158 shares of Series B Preferred Stock (that are convertible into 2,842,158 shares of common stock) remained outstanding. Equity Incentive Plans The Company has multiple equity incentive plans under which it grants awards. As of March 31, 2022, there are 79,465 shares available to grant under the 2014 Equity Incentive Plan (the “2014 Plan”). On April 22, 2018, the Company’s board of directors (the “Board”) adopted the Iovance Biotherapeutics, Inc. 2018 Equity Incentive Plan (the “2018 Plan”), which was approved by the Company’s stockholders in June 2018. The 2018 Plan as approved initially authorized the issuance up to an aggregate of 6,000,000 shares of common stock in the form of incentive (qualified) stock options, non-qualified options, common stock, stock appreciation rights, restricted stock awards, restricted stock units, other stock-based awards, other cash-based awards or any combination of the foregoing. On June 8, 2020, the Company's stockholders approved an amendment to the 2018 Plan to increase the number of shares available for issuance upon the exercise of stock options under the 2018 Plan from 6,000,000 to 14,000,000 shares, which became effective immediately. As of March 31, 2022, 1,058,461 shares of common stock were available for grant under the Company’s 2018 Plan. On September 22, 2021, the Board adopted the Iovance Biotherapeutics, Inc. 2021 Inducement Plan (the “2021 Inducement Plan”). The 2021 Inducement Plan provides for the grant of non-qualified options, common stock, stock appreciation rights, restricted stock awards, restricted stock units, other stock-based awards, other cash-based awards, or any combination of the foregoing. The 2021 Inducement Plan was recommended for approval by the Compensation Committee of the Board (the “Compensation Committee”), and subsequently approved and adopted by the Board without stockholder approval pursuant to Rule 5635(c)(4) of the rules and regulations of The Nasdaq Stock Market, LLC (the “Nasdaq Listing Rules”). The Board initially reserved 1,000,000 shares of the Company’s common stock for issuance pursuant to equity awards granted under the 2021 Inducement Plan, and the 2021 Inducement Plan is administered by the Compensation Committee. On January 12, 2022, the Compensation Committee approved an amendment to the 2021 Inducement Plan solely to increase the number of shares reserved for issuance under the 2021 Inducement Plan from 1,000,000 shares of the Company’s common stock to 1,750,000 shares of the Company’s common stock without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules. In accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules, equity awards under the 2021 Inducement Plan may only be made to an employee if such employee is granted such equity awards in connection with his or her commencement of employment with the Company or a subsidiary and such grant is an inducement material to his or her entering into employment with the Company or such subsidiary. In addition, awards under the 2021 Inducement Plan may only be made to employees who have not previously been an employee or member of the Board (or any parent or subsidiary of the Company) or following a bona fide period of non-employment of the employee by the Company (or a parent or subsidiary of the Company). As of March 31, 2022, 552,925 shares of common stock were available for grant under the 2021 Inducement Plan. Stock Options A summary of the stock option activity during the three months ended March 31, 2022, is presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ Number ​ Average ​ Remaining ​ Intrinsic ​ ​ of ​ Exercise ​ Contract ​ Value ​ Options Price Life (in thousands) Outstanding at December 31, 2021 ​ 12,520,865 $ 25.05 ​ ​ ​ ​ ​ Issued ​ 1,887,052 ​ 14.69 ​ ​ ​ ​ ​ Exercised ​ (163,579) ​ 8.65 ​ ​ ​ ​ ​ Expired/Cancelled ​ (142,812) ​ 29.52 ​ ​ ​ ​ ​ Outstanding at March 31, 2022 ​ 14,101,526 $ 23.81 7.83 ​ $ 27,587 Ending vested and expected to vest at March 31, 2022 ​ 14,101,526 ​ $ 23.81 ​ 7.83 ​ $ 27,587 Options exercisable at March 31, 2022 7,543,738 ​ $ 20.50 6.74 ​ $ 23,859 ​ As of March 31, 2022, there was $94.1 The weighted average grant date fair value for employee options granted under the Company’s stock option plans during the three months ended March 31, 2022 and 2021 was $8.81 The aggregate intrinsic value in the table above reflects the total pre-tax intrinsic value (calculated as the difference between the Company’s closing stock price on the last trading day of the quarter ended March 31, 2022 and the exercise price of the options, multiplied by the number of in-the-money stock options) that would have been received by the option holders had all option holders exercised their options on March 31, 2022. The intrinsic value of the Company’s stock options changes based on the closing price of the Company’s common stock. Employee Stock Purchase Plan In June 2020, the Company adopted the 2020 ESPP upon its approval by the Company’s shareholders at its Annual Stockholders Meeting on June 8, 2020. The Company reserved 500,000 shares of its common stock for issuance under the 2020 ESPP. Under the 2020 ESPP, employees of the Company can purchase shares of its common stock based on a percentage of their compensation subject to certain limits. The purchase price per share is equal to the lower of 85% of the fair market value of its common stock on the offering date or the purchase date with a six month look-back feature. The 2020 ESPP purchases are settled with common stock from the 2020 ESPP’s previously authorized and available pool of shares. The compensation expense related to the 2020 ESPP for the three months ended March 31, 2022 and 2021 was $0.2 million and $0.3 million, respectively. As of March 31, 2022, 94,148 shares had been issued to date under the 2020 ESPP and there was $0.2 million of unrecognized compensation cost associated with the 2020 ESPP, which is expected to be recognized over the remaining 2.3 months. Restricted Stock Units and Performance Restricted Stock Units In addition to RSUs that have time-based vesting requirements, from time to time the Company may issue RSUs that include certain performance vesting criteria based upon the satisfaction of stated objectives (“PRSUs”). Compensation expense related to PRSUs is based on the grant date fair value of the award and recorded from the period that achievement is determined to be probable through the stated service period associated with the award. Activity for RSUs and PRSUs units during the three months ended March 31, 2022 is presented in the following table: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number ​ Average ​ ​ of ​ Grant Date ​ RSUs and PRSUs Fair Value Outstanding, non-vested as of December 31, 2021 ​ 1,110,010 ​ $ 23.87 Granted ​ 2,027,774 ​ ​ 15.18 Canceled/Forfeited ​ (42,607) ​ ​ 19.43 Outstanding, non-vested as of March 31, 2022 ​ 3,095,177 ​ $ 18.24 ​ As of March 31, 2022, there was $37.0 Stock-Based Compensation Total stock-based compensation expense related to all of the Company’s stock-based awards was recorded on the Condensed Consolidated Statements of Operations as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2022 2021 Research and development ​ $ 13,651 ​ $ 9,202 General and administrative ​ 8,614 ​ 7,739 Total stock-based compensation expense ​ $ 22,265 ​ $ 16,941 ​ Total stock-based compensation expense by type of award was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2022 2021 Stock option expense ​ $ 14,867 ​ $ 16,660 Restricted stock expense ​ 7,162 ​ — ESPP expense ​ 236 ​ 281 Total stock-based compensation expense ​ $ 22,265 ​ $ 16,941 ​

LICENSES AND AGREEMENTS

LICENSES AND AGREEMENTS	3 Months Ended
	Mar. 31, 2022
LICENSES AND AGREEMENTS
LICENSES AND AGREEMENTS	NOTE 7. LICENSES AND AGREEMENTS National Institutes of Health (the “NIH”) and the National Cancer Institute (the “NCI”) Cooperative Research and Development Agreement (the “CRADA”) In August 2011, the Company signed a five-year CRADA with the NCI to work on the development of adoptive cell immunotherapies that are designed to destroy metastatic melanoma cells. The CRADA was amended in 2015 and 2016 to, among other things, extend the term of the CRADA through August 2021, include new indications such as the development of TIL therapy for the treatment of patients with bladder, lung, triple-negative breast, and Human Papilloma Virus (“HPV”)-associated cancers, and modify the focus on the development of unmodified TIL as a stand-alone therapy or in combination. The parties have continued the development of improved methods for the generation and selection of TIL with anti-tumor reactivity in metastatic melanoma, bladder, lung, breast, and HPV-associated cancers. In August 2021, the NCI and the Company entered into a third amendment to the CRADA. The third amendment, among other things, extended the term of the CRADA by three years to August 2024. The research plan in this amendment includes the evaluation in clinical trials of strategies for development of more potent TILs, such as selection of CD39/69 double negative cells and the use of certain inhibitors or other reagents in TIL expansion cultures. Pursuant to the terms of the CRADA, as amended, the Company is required to make quarterly payments of $0.5 million to the NCI for support of research activities. To the extent the Company licenses patent rights relating to a TIL-based product candidate, the Company will be responsible for all patent-related expenses and fees, past and future, relating to the TIL-based product candidate. In addition, the Company may be required to supply certain test articles, including TIL, grown and processed under Current Good Manufacturing Practice (“cGMP”) conditions, suitable for use in clinical trials. The extended CRADA has a three-year term expiring in August 2024. The Company or the NCI may unilaterally terminate the CRADA for any reason or for no reason at any time by providing written notice at least 60 days before the desired termination date. The Company recorded costs associated with the CRADA of $0.5 million for each of the three months ended March 31, 2022 and 2021, respectively, as research and development expenses. Patent License Agreement Related to the Development and Manufacture of TIL The Company entered into an Exclusive Patent License Agreement (the “Patent License Agreement”) with the NIH, an agency of the U.S. Public Health Service within the Department of Health and Human Services, in 2011, as amended in 2015. Pursuant to the Patent License Agreement, as amended, the NIH granted the Company licenses, including exclusive, co-exclusive, and non-exclusive licenses, to certain technologies relating to autologous tumor infiltrating lymphocyte adoptive cell therapy products for the treatment of metastatic melanoma, lung, breast, bladder and HPV-positive cancers. Effective May 6, 2021, the Company entered into an Amended and Restated Patent License Agreement with NIH (the “Amended and Restated Patent License Agreement”), which includes the grant of additional exclusive, worldwide patent rights in the Indications to cytokine-tethered TIL technology, and expands the non-exclusive, worldwide field of use to all cancers. The Amended and Restated Patent License Agreement requires the Company to pay royalties based on a percentage of net sales in jurisdictions where patent rights exist, which percentage can fall into a tier that may be less than one percent to mid-single digits depending upon certain events, including the exclusivity of the rights, and the Company expects lower overall royalty payments as a result. The Company also agreed to potential milestone payments on the achievement of certain clinical, regulatory, and commercial sales milestones for each of the Indications and other direct costs incurred by the NIH pursuant to the Amended and Restated Patent License Agreement. The Company anticipates making milestone payments, including a payment in the low-single-digit millions of dollars in conjunction with the approval of a Biologics License Application for any of its product candidates covered by the Amended and Restated Patent License Agreement. The term of the Amended and Restated Patent License Agreement continues until the expiry of the last-to-expire patent rights licensed thereunder, and the agreement contains standard termination provisions. Exclusive Patent License Agreement Related to TIL Selection On February 10, 2015, the Company entered into an exclusive patent license agreement (the “Exclusive Patent License Agreement”) with the NIH under which the Company received an exclusive license to the NIH’s rights to patent-pending technologies related to methods for improving adoptive cell therapy through more potent and efficient production of TIL from melanoma tumors by selecting for T cell populations that express various inhibitory receptors. Unless terminated sooner, the license shall remain in effect until the last licensed patent right expires. Under the Exclusive Patent License Agreement, the Company agreed to pay customary royalties based on a percentage of net sales of a licensed product (which percentage is in the mid-single digits), a percentage of revenues from sublicensing arrangements, and lump sum benchmark payments upon the successful completion of clinical studies involving licensed technologies, the receipt of the first Food and Drug Administration (the “FDA”) approval or foreign equivalent for a licensed product or process resulting from the licensed technologies, the first commercial sale of a licensed product or process in the U.S., and the first commercial sale of a licensed product or process in any foreign country. H. Lee Moffitt Cancer Center Research Collaboration and Clinical Grant Agreements with Moffitt In June 2020, the Company entered into a Sponsored Research Agreement with the H. Lee Moffitt Cancer Center (“Moffitt”), with a term that ends either upon completion of the research thereunder or on July 1, 2022, whichever is sooner, and under which immaterial payments will be made to Moffitt in connection with the research services thereunder. In December 2016, the Company entered into a clinical grant agreement with Moffitt to support an ongoing clinical trial at Moffitt that combines TIL therapy with nivolumab for the treatment of patients with metastatic melanoma. In June 2017, the Company entered into a second clinical grant agreement with Moffitt to support a new clinical trial at Moffitt that combines TIL therapy with nivolumab for the treatment of patients with non-small cell lung cancer, under which the Company obtained a non-exclusive, royalty-free license to any new Moffitt inventions made in the performance of the agreement. Under both clinical grant agreements with Moffit, the Company has non-exclusive rights to clinical data arising from the respective clinical trials. The Company recorded $0.1 million and $0.2 million of research and development expense for the three months ended March 31, 2022 and 2021 respectively, in connection with the research collaboration and clinical grant agreements with Moffitt. Exclusive License Agreements with Moffitt The Company entered into a license agreement with Moffitt (the “First Moffitt License”), effective as of June 28, 2014, under which the Company received a world-wide license to Moffitt’s rights to patent-pending technologies related to methods for improving TIL for adoptive cell therapy using toll-like receptor agonists. Unless earlier terminated, the term of the license extends until the earlier of the expiration of the last issued patent related to the licensed technology or 20 years after the effective date of the license agreement. Pursuant to the First Moffitt License, the Company paid an upfront licensing fee in the amount of $0.1 million which was recorded as research and development expense. A patent issuance fee will also be payable under the First Moffitt License, upon the issuance of the first U.S. patent covering the subject technology. In addition, the Company agreed to pay milestone license fees upon completion of specified milestones, customary royalties based on a specified percentage of net sales (which percentage is in the low single digits) and sublicensing payments, as applicable, and annual minimum royalties beginning with the first sale of products based on the licensed technologies, which minimum royalties will be credited against the percentage royalty payments otherwise payable in that year. The Company will also be responsible for all costs associated with the preparation, filing, maintenance and prosecution of the patent applications and patents covered by the First Moffitt License related to the treatment of any cancers in the U.S., Europe, and Japan and in other countries designated by the Company in agreement with Moffitt. No expenses were recorded for the First Moffitt License for the three months ended March 31, 2022 and 2021. The Company entered into a second license agreement with Moffitt effective as of May 7, 2018 (the “Second Moffitt License”), under which the Company received a license to Moffitt’s rights to patent-pending technologies related to the use of 4-1BB agonists in conjunction with TIL manufacturing processes and therapies. Pursuant to the Second Moffitt License, the Company paid an upfront licensing fee in the amount of $0.1 million in 2018. An annual license maintenance fee is also payable commencing on the first anniversary of the effective date. In addition, the Company agreed to pay an annual commercial use payment for each indication for which a first sale has occurred, which in the aggregate amounts to up to $0.4 million a year. The Company recorded a de minimis amount for the three months ended March 31, 2022 and 2021 as research and development expenses in connection with this agreement. The Company subsequently exercised an option to exclusively license Moffitt’s rights to patent pending technologies related to the use of tumor digests in conjunction with TIL manufacturing processes and therapies and entered into an amended and restated Second Moffitt License in October 2021 (the “Amended & Restated Second Moffit License”), to include these rights. Pursuant to the Amended & Restated Second Moffitt License, the Company paid an upfront licensing fee in the amount of $0.2 million in 2021, which was recorded as research and development expense. In addition, the Company agreed to pay an annual commercial use payment for each indication for which a first sale has occurred for products relating to the use of 4-1BB antagonists and for products relating to the use of tumor digests covered by the license. The University of Texas M.D. Anderson Cancer Center Strategic Alliance Agreement On April 17, 2017, the Company entered into a Strategic Alliance Agreement (the “SAA”) with The University of Texas M.D. Anderson Cancer Center (“MDACC”) under which the Company and MDACC agreed to conduct clinical and preclinical research studies. The Company agreed in the SAA to provide total funding not to exceed approximately $14.2 million for the performance of the multi-year studies under the SAA, of which approximately $7.0 million has been funded cumulatively through March 31, 2022, and has been recorded as research and development expense . WuXi Advanced Therapies, Inc. In November 2016, the Company entered into a three-year manufacturing and services agreement (“MSA”) with WuXi Advanced Therapies, Inc. (“WuXi”) pursuant to which WuXi agreed to provide manufacturing and other services, which has since been amended and assigned to its subsidiary Iovance Biotherapeutics Manufacturing LLC. Under the MSA, the Company entered into two statements of work for two cGMP manufacturing suites to be established and operated by WuXi for the Company, both of the suites are expected to be capable of being used for the commercial manufacture of its products. The terms of the two statements of work were both extended to December 2022. The Company recorded costs associated with agreements with WuXi of $3.9 million and $3.4 million for the three months ended March 31, 2022 and 2021, respectively, as research and development expenses. Cellectis S.A. On December 31, 2019, the Company entered into a research collaboration and exclusive worldwide license agreement whereby the Company will license gene-editing technology from Cellectis S.A. (“Cellectis”), a clinical-stage biopharmaceutical company, to develop TIL therapies that have been genetically edited. Financial terms of the license include development, regulatory and sales milestone payments from the Company to Cellectis, as well as royalty payments based on net sales of TALEN®-modified TIL products. The Company recorded costs associated with the license agreement with Cellectis of $0.1 million for each of the three months ended March 31, 2022 and 2021, respectively, as research and development expense. Novartis Pharma AG On January 12, 2020, the Company obtained a license from Novartis Pharma AG (“Novartis”) to develop and commercialize an antibody cytokine engrafted protein, which the Company refers to as IOV-3001. Under the agreement, the Company has paid an upfront payment to Novartis and may pay future milestones related to initiation of patient dosing in various phases of clinical development for IOV-3001 and approval of the product in the U.S, EU, and Japan. Novartis is also entitled to low-to-mid single digit percentage royalties from commercial sales of the product. The Company recorded costs associated with the license agreement from Novartis of $10.0 million as research and development expenses during the fiscal year ended December 31, 2020. No expenses were recorded for the three months ended March 31, 2022 or 2021.

LEASES

LEASES	3 Months Ended
	Mar. 31, 2022
LEASES
LEASES	NOTE 8. LEASES Operating Leases The Company leases corporate office space in California, including 49,918 square feet for its current corporate headquarters’ office space in San Carlos, California, manufacturing, research and development lab facilities and office space in Philadelphia, Pennsylvania, including 136,000 square feet of commercial manufacturing and lab space at the i The Company’s leases have remaining lease terms of less than one year to approximately 20 years. Some of our leases include one or more options to renew with renewal terms that can extend the lease for additional years, or options to terminate the leases, both at the Company’s discretion. The Company’s leases may include options to extend or terminate the lease, which is considered in the lease term when it is reasonably certain that the Company will exercise any such options. Lease expense for minimum lease payments is recognized on a straight-line basis based on the fixed components of a lease arrangement. Variable lease cost is determined based on performance or usage in accordance with the contractual agreements, and not based on an index or rate. Such costs that are not fixed in nature are recognized as incurred. The Company also leases certain furniture and equipment that has a lease term of 12 months or less. Since the lease agreement do not include an option to purchase the underlying asset, the Company elected not to apply the recognition requirements of Topic 842 for short-term leases, however, the lease costs that pertain to the short-term leases are disclosed in the components of lease costs table below. Manufacturing Contracts The Company uses contract manufacturing organizations (collectively the “CMOs” and each a “CMO”) to manufacture and supply TILs for clinical and commercial purposes. The CMO contractual obligations consist of the use of manufacturing facilities and minimum fixed commitment fees, such as personnel, general support fees, and minimum production or material fees. In addition to the minimum fixed commitment fees, the CMO contractual obligations include variable costs such as production and material costs in excess of the minimum quantity specified in each CMO agreement. During the term of each CMO agreement, the Company has access to and control of the use of a dedicated suite in each of the CMOs’ facilities for manufacturing activities. The contracts with CMOs generally contain embedded operating leases based on the fact that the suites are used for the Company’s production are implicitly identified, are used exclusively by the Company during the contractual term of the arrangements, and the CMOs have no substantive contractual rights to substitute the facilities used by the Company. Further, the Company controls the use of the facilities by obtaining all of the economic benefits from the use of the facilities and direct the use of the facilities throughout the period of use. The terms of the CMO contracts include options to terminate the lease with an advance notice of five to six months. The termination clauses and extension clauses are included in the calculation of the lease term for each of the CMOs when it is reasonably certain that it will not exercise such options. For contracts with multiple deliverables, Topic 842 requires the Company to first identify a lease deliverable and non-lease deliverable included in the arrangements, and then allocate the fixed contractual consideration to the lease deliverable(s) and the non-lease deliverable(s) on a relative standalone selling price basis to determine the amount of operating lease right-of-use assets and liabilities. The Company identified the use of a dedicated suite as a single lease deliverable, and related labor services as a single non-lease deliverable in each of the CMO arrangements. Judgment is required to determine the relative standalone selling price of each deliverable as the observable standalone selling prices are not readily available. Therefore, management uses estimates and assumptions in determining relative standalone selling price of lease of a suite and labor service using information that includes market and other observable inputs to the extent possible. The balance sheet classification of the Company’s right-of-use asset and lease liabilities was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2022 ​ 2021 Operating lease right-of-use assets ​ $ 73,475 ​ $ 68,983 Operating lease liabilities ​ ​ ​ ​ ​ Current portion included in current liabilities ​ ​ 7,710 ​ 5,057 Long-term portion included in non-current liabilities ​ ​ 71,184 ​ 65,474 Total operating lease liabilities ​ $ 78,894 ​ $ 70,531 ​ The following table summarizes components of lease expenses, which were included in Total costs and expenses in the Company’s Condensed Consolidated Statements of Operations, and other information related to its operating leases as follows (in thousands except weighted-average remaining lease terms and discount rates): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2022 ​ 2021 Operating lease cost ​ $ 4,555 ​ $ 3,398 ​ Variable lease cost ​ 980 ​ 710 ​ Short-term lease cost ​ 42 ​ 36 ​ Total lease cost ​ $ 5,577 ​ $ 4,144 ​ ​ ​ ​ ​ ​ ​ ​ ​ Other information ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in the measurement of lease liabilities included in Operating cash flows ​ $ 3,811 ​ $ 2,466 ​ Tenant improvement allowance received for amounts included in the measurement of lease liabilities included in Operating cash flows ​ $ 3,115 ​ $ 144 ​ Right-of-use assets obtained from entering new leases ​ $ — ​ $ 618 ​ Increase in right-of-use assets from lease modifications ​ $ 7,673 ​ $ 2,159 ​ Weighted-average remaining lease terms (years) ​ ​ 14.13 ​ ​ 17.55 ​ Weighted-average discount rates ​ ​ 7.2% ​ ​ 7.4% ​ ​ As of March 31, 2022, the maturities of the Company’s operating lease liabilities were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CMO ​ ​ ​ ​ Facility ​ embedded ​ ​ ​ Year Ending December 31, ​ leases leases Total 2022 ​ $ 4,332 ​ $ 6,317 ​ $ 10,648 2023 ​ 8,015 ​ 3,120 ​ 11,135 2024 ​ 8,215 ​ — ​ 8,215 2025 ​ 8,116 ​ — ​ 8,116 2026 ​ 7,989 ​ — ​ 7,989 Thereafter ​ 92,013 ​ — ​ 92,013 Total lease payments ​ $ 128,678 ​ $ 9,437 ​ $ 138,115 Less: Present value adjustment ​ (55,300) ​ (425) ​ (55,725) Future tenant improvement reimbursement ​ ​ (3,496) ​ ​ — ​ ​ (3,496) Operating lease liabilities ​ $ 69,883 ​ $ 9,012 ​ $ 78,894 ​ For its corporate headquarters’ office, the lease agreement includes a tenant improvement allowance of $8.2 million. As of March 31, 2022, the Company has received total reimbursements associated with this tenant improvement allowance of $4.7 million, of which $3.1 million was received during the three months ended March 31, 2022.

LEGAL PROCEEDINGS

LEGAL PROCEEDINGS	3 Months Ended
	Mar. 31, 2022
LEGAL PROCEEDINGS
LEGAL PROCEEDINGS	NOTE 9. LEGAL PROCEEDINGS Derivative Lawsuit. its current directors, as defendants, in the Court of Chancery in the State of Delaware. The complaint alleges breach of fiduciary duty and a claim for unjust enrichment in connection with alleged excessive compensation of certain non-executive directors of the Company . The defendants intend to vigorously defend against the foregoing complaints. Based on the early stage of the litigation, it is not possible to estimate the amount or range of possible loss that might result from these matters. Solomon Capital, LLC. Solomon Capital, LLC, Solomon Capital 401(K) Trust, Solomon Sharbat and Shelhav Raff v. Lion Biotechnologies, Inc. New York, County of New York (index no. 651881/2016). The Solomon Plaintiffs allege that, between June and November 2012, they provided to the Company $0.1 million and that they advanced and paid on behalf of the Company an additional $0.2 million. The complaint further alleges that the Company agreed to (i) provide them with promissory notes totaling $0.2 million, plus interest, (ii) issue a total of 1,110 shares to the Solomon Plaintiffs (after the 1-for-100 reverse split of the Company’s common stock effected in March 2013) (the “Equity Claim”), and (iii) allow the Solomon Plaintiffs to convert the foregoing funds into its securities in the next financing of the Company on the same terms offered to other investors, which Solomon Plaintiffs allege, should have given them the right to convert their advances and payments into shares of the Company's common stock in the restructuring that took effect in May 2013. Based on the foregoing, the Solomon Plaintiffs allege causes for breach of contract and unjust enrichment and demand judgment against the Company in an unspecified amount exceeding $1.5 million, plus interest. On June 3, 2016, the Company filed an answer and counterclaims in the lawsuits. The Company has asserted counterclaims for fraudulent inducement, fraudulent misrepresentation, fraudulent concealment, breach of fiduciary duty, and breach of contract, alleging principally that the counterclaim defendants misrepresented their qualifications and failed to disclose that Solomon Sharbat was the subject of an investigation by the Financial Industry Regulatory Authority (“FINRA”) that resulted in the loss of his FINRA license. In its counterclaims, the Company is seeking damages in an amount exceeding $0.5 million and an order rescinding any and all agreements that the Solomon Plaintiffs contend entitled them to obtain shares of Company stock. On May 12, 2020, the court granted the Company’s motion for summary judgment limiting the Solomon Plaintiffs’ damages for the Equity Claim to $47,420. The Solomon Plaintiffs filed a notice of appeal of this summary judgment on June 9, 2020. On July 2, 2020, the court granted the Company’s motion to dismiss the First Solomon Suit for want of prosecution. On January 4, 2021, the court granted the Solomon Plaintiffs motion for reconsideration, and reinstituted the case. On January 15, 2021, the Company filed a notice of appeal of the court’s grant of the Solomon Plaintiffs motion for reconsideration. On May 11, 2021, the Appellate Division upheld the court’s grant of the Solomon Plaintiffs’ motion for reconsideration of the dismissal of the First Solomon Suit for want of prosecution. On September 27, 2019, the Solomon Plaintiffs filed a new lawsuit (through new legal counsel) (“the Second Solomon Suit”) titled Solomon Capital, LLC, Solomon Capital 401(K) Trust, Solomon Sharbat and Shelhav Raff v. Iovance Biotherapeutics, Inc., f/k/a/ Lion Biotechnologies Inc. f/k/a/ Genesis Biopharma Inc., and Manish Singh The Company intends to vigorously defend these complaints and pursue its counterclaims, as applicable. At the current stage of the litigation, in both the First Solomon Suit and the Second Solomon Suit, it is not possible to estimate the amount or range of possible loss that might result from an adverse judgment or a settlement of these matters. The Company may be involved, from time to time, in legal proceedings and claims arising in the ordinary course of its business. Such matters are subject to many uncertainties and outcomes are not predictable with assurance. The Company accrues amounts, to the extent they can be reasonably estimated, that it believes are adequate to address any liabilities related to legal proceedings and other loss contingencies that it believes will result in a probable loss. While there can be no assurances as to the ultimate outcome of any legal proceeding or other loss contingency involving the Company, management does not believe any pending matter will be resolved in a manner that would have a material adverse effect on its financial position, results of operations or cash flows.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2022
INCOME TAXES
INCOME TAXES	NOTE 10. INCOME TAXES The Company did not record income tax expense for the three months ended March 31, 2022 and 2021, respectively as the Company expected to be in a taxable loss position in 2022 and 2021, and the net deferred tax assets are fully offset by a valuation allowance as it is not more likely than not that the benefit will be realized. As of March 31, 2022, the Company remains in a cumulative book loss position and does not have sufficient positive evidence to realize its net deferred tax assets. As such, the Company continues to maintain a full valuation allowance against its net deferred tax assets.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING PRACTICES (Policies)	3 Months Ended
	Mar. 31, 2022
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Cash, Cash Equivalents, and Investments	Cash, Cash Equivalents, and Investments The Company’s cash and cash equivalents include short-term investments with original maturities of three months or less when purchased. The Company's investments are classified as “available-for-sale.” The Company includes these investments in current assets or non-current assets in the Condensed Consolidated Balance Sheets based on the length of maturity from the reporting date and carries them at fair value. Unrealized gains and losses on available-for-sale securities are recorded in accumulated other comprehensive loss. Impairment losses related to credit losses (if any) are recorded as an allowance for credit losses with an offsetting entry to Interest income, net. No impairment losses related to credit losses were recognized for the three months ended March 31, 2022 and 2021. The cost of debt securities is adjusted for the amortization of premiums and accretion of discounts to maturity. Such amortization and accretion are included in Interest income, net in the Condensed Consolidated Statements of Operations. Gains and losses on securities sold are recorded based on the specific identification method and are included in Interest income, net in the Condensed Consolidated Statements of Operations. The Company has not incurred any realized gains or losses from sales of securities to date. The Company’s investment policy limits investments to certain types of instruments such as certificates of deposit, money market instruments, obligations issued by the U.S. government and U.S. government agencies as well as corporate debt securities and commercial paper, and places restrictions on maturities and concentration by type and issuer, except for securities issued by the U.S. government.
Restricted Cash	Restricted Cash The Company maintains a required minimum balance in a segregated bank account in connection with three letters of credit, one for $5.45 million for the benefit of the landlord for the i The following table provides a reconciliation of cash, cash equivalents, and restricted cash, reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2022 ​ 2021 Cash and cash equivalents ​ $ 92,360 ​ $ 131,954 Restricted cash ​ 6,084 ​ 6,084 Total cash, cash equivalents and restricted cash ​ $ 98,444 ​ $ 138,038
Net Loss per Share	Net Loss per Share Basic net loss per share is computed by dividing the net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the sum of the weighted average number of shares of common stock outstanding and the dilutive common stock equivalents outstanding during the period. The Company’s potentially dilutive common stock equivalent shares, which include incremental common shares issuable upon (i) the exercise of outstanding stock options, (ii) purchases though the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), (iii) vesting of restricted stock units, and (iv) conversion of preferred stock, are only included in the calculation of diluted net loss per share when their effect is dilutive. As of March 31, 2022 and 2021, the following outstanding common stock equivalents have been excluded from the calculation of net loss per share because their impact would be anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ 2022 2021 Stock options ​ 14,101,526 15,419,226 Employee Stock Purchase Plan ​ 86,448 ​ 55,963 Restricted stock units ​ 3,095,177 ​ — Series A Convertible Preferred Stock* ​ 97,000 ​ 97,000 Series B Convertible Preferred Stock* ​ 2,842,158 2,842,158 ​ ​ 20,222,309 18,414,347 * on an as-converted basis The dilutive effect of potentially dilutive securities would be reflected in diluted earnings per common share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of the Company's common stock could result in a greater dilutive effect from potentially dilutive securities.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Significant items subject to such estimates and assumptions include assumptions made in the fair value of equity awards and related stock-based compensation, assumptions used in measuring operating right-of-use assets and operating lease liabilities, accounting for potential liabilities, including estimates inherent in accruals related to clinical trials, and the realizability of the Company’s deferred tax assets .
Principles of Consolidation	Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of Iovance Biotherapeutics, Inc. and its wholly-owned subsidiaries, Iovance Biotherapeutics Manufacturing LLC, Iovance Biotherapeutics GmbH, and Iovance Biotherapeutics B.V . All intercompany accounts and transactions have been eliminated. The U.S. dollar is the functional currency for all the Company's consolidated operations.
Leases	Leases The Company determines if an arrangement includes a lease at inception and thereafter, if modified. Operating leases are included in its Condensed Consolidated Balance Sheets as Operating lease right-of-use assets and Operating lease liabilities as of March 31, 2022 and December 31, 2021. Operating lease right-of-use assets represent the Company’s right to use an underlying asset for the lease term and operating lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date or modification date based on the present value of lease payments over the lease term. In determining the net present value of lease payments, the Company uses an estimated incremental borrowing rate that is applicable to the Company based on the information available at the later of the lease commencement or modification date. The operating lease right-of-use assets also include any lease payments made less lease incentives. The Company’s leases may include options to extend or terminate the lease, which is considered in the lease term when it is reasonably certain that the Company will exercise any such options. Lease expense is recognized on a straight-line basis over the expected lease term and recorded in costs and expenses in the Condensed Consolidated Statements of Operations. The Company has elected not to apply the recognition requirements of Accounting Standards Update (“ASU”) No. 2016-02 and No. 2018-10 (together “Topic 842”) for short-term leases. For lease agreements entered into by the Company that include lease and non-lease components, such components are generally accounted for separately.
Stock-Based Compensation	Stock-Based Compensation The Company periodically grants stock options to employees and non-employees as compensation for services rendered. The Company accounts for all stock-based payment awards made to employees, including the employee stock purchase plans, and non-employees in accordance with the authoritative guidance provided by the Financial Accounting Standards Board (“FASB”) where the value of the award is measured on the date of grant and recognized over the vesting period. Forfeitures are recognized in the period in which they occur. The Company accounts for stock option grants to non-employees in a similar manner as stock option grants to employees except for the term used in the grant date fair value, therefore no longer requiring a re-measurement at the then-current fair values at each reporting date until the shares underlying the options have vested. The non-employee awards that contain a performance condition that affects the quantity or other terms of the award are measured based on the outcome that is probable. The fair value of the Company's common stock option grants is estimated using a Black-Scholes option pricing model, which uses certain assumptions related to risk-free interest rates, expected volatility, expected term of the common stock options, and future dividends. The stock-based compensation expense is recorded based upon the value derived from the Black-Scholes option pricing model. The assumptions used in the Black-Scholes option pricing model could affect compensation expense recorded in future periods. The Company issues restricted stock units (“RSUs”) from time to time as part of its equity incentive plans. The Company measures the compensation cost with respect to RSUs issued to employees based upon the estimated fair value of the equity instruments at the date of the grant, which is recognized as an expense over the period during which an employee is required to provide services in exchange for the awards. The fair value of RSUs is based on the closing price of the Company’s common stock on the grant date.
Accrued Research and Development Costs	Accrued Research and Development Costs Research and development costs are expensed as incurred. Clinical development costs compose a significant component of research and development costs. The Company has a history of contracting with third parties, including contract research organizations (“CROs”), independent clinical investigators, and contract manufacturing organizations (“CMOs”) that perform various clinical trial activities on the Company’s behalf in connection with the ongoing development of the Company’s product candidates. The financial terms of these contracts are subject to negotiations and may vary from contract to contract and may result in uneven payment flow. The Company accrues and expenses costs for clinical trial activities performed by third parties based upon estimates of work completed to date for each clinical trial in accordance with agreements established with CROs, hospitals, and clinical investigators. Accruals for CROs and CMOs are recorded based on estimates of services received and efforts expended pursuant to agreements established with CROs, CMOs and other outside service providers. The Company determines its estimates through discussions with internal clinical stakeholders and outside service providers as to the progress or stage of completion of clinical trials or services and the contracted fee to be paid for such services. Included in the Company’s clinical development costs are investigator costs, which are costs associated with treatments administered at clinical sites as required under each clinical study protocol. The Company’s estimates for clinical investigator costs and timing of expense recognition will depend on a number of factors that include, but are not limited to, (i) the overall number of patients that enroll in the trial at each individual site, (ii) the length of study enrollment period, (iii) discontinuation and completion rates of patients, (iv) duration of patient safety follow-ups, (v) the number of sites included in the clinical trial, and (vi) the contracted fee of each participating site for patient treatment while on study, which can vary greatly for several reasons including, but not limited to, geographic region, medical center or physician costs, and overhead costs. In addition, the Company’s estimates for per patient trial costs will vary based on a number of factors that include, but are not limited to, the extent of additional treatments that may be administered by investigators as a result of patient health status, recoverability of patient costs through insurance carriers of patients, and unanticipated cost of injuries incurred as a result of the study treatment. The Company accrues for estimated expenses resulting from obligations under investigator site agreements as the timing of payments does not always timely align with the periods over which the treatments are administered by the clinical investigators. These estimates are typically based on contracted amounts, patient visit data, discussions with internal clinical stakeholders and outside service providers, and historical look-back analysis of actual payments made to date. The Company makes judgements and estimates in determining the accrual balance in each reporting period. In the event advance payments are made to a CRO, CMO or other outside service provider, the payments are recorded within prepaid expenses and other current assets in the Condensed Consolidated Balance Sheets and subsequently recognized as research and development expense in the Condensed Consolidated Statements of Operations when the associated services have been performed. As actual costs become known, the Company adjusts its estimates, liabilities and assets. Inputs used in the determination of estimates discussed above may vary from actual, which will result in adjustments to research and development expense in future periods. Changes in these estimates that result in material changes to the Company’s accruals could materially affect its results of operations. The Company’s historical estimates have not been materially different from actual amounts recorded.
Segment reporting	Segment Reporting The Company operates in one segment, focused on developing and commercializing therapies using autologous TIL for the treatment of metastatic melanoma and other solid tumor cancers.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	3 Months Ended
	Mar. 31, 2022
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Schedule of cash and cash equivalents and restricted cash	The following table provides a reconciliation of cash, cash equivalents, and restricted cash, reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statements of Cash Flows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ ​ 2022 ​ 2021 Cash and cash equivalents ​ $ 92,360 ​ $ 131,954 Restricted cash ​ 6,084 ​ 6,084 Total cash, cash equivalents and restricted cash ​ $ 98,444 ​ $ 138,038
Schedule of Antidilutive securities excluded from computation of earnings per share	​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ 2022 2021 Stock options ​ 14,101,526 15,419,226 Employee Stock Purchase Plan ​ 86,448 ​ 55,963 Restricted stock units ​ 3,095,177 ​ — Series A Convertible Preferred Stock* ​ 97,000 ​ 97,000 Series B Convertible Preferred Stock* ​ 2,842,158 2,842,158 ​ ​ 20,222,309 18,414,347 * on an as-converted basis

CASH EQUIVALENTS, INVESTMENTS_2

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2022
CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS
Schedule of cost and fair value of cash equivalents and short-term investments	The amortized cost, fair value measurements, and fair value of cash equivalents and investments as of March 31, 2022 and December 31, 2021 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ ​ ​ As of March 31, 2022 Cost Gains Losses Fair Value U.S. treasury securities ​ $ 248,546 ​ $ — ​ $ (2,062) ​ $ 246,484 U.S. government agency securities ​ 5,067 ​ — ​ (21) ​ 5,046 Corporate securities ​ ​ 34,408 ​ ​ — ​ ​ (79) ​ ​ 34,329 Commercial paper ​ ​ 158,276 ​ ​ 1 ​ ​ (182) ​ ​ 158,095 Money market funds ​ ​ 45,249 ​ ​ — ​ ​ — ​ ​ 45,249 Total investments ​ $ 491,546 ​ $ 1 ​ $ (2,344) ​ $ 489,203 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ ​ ​ As of December 31, 2021 Cost Gains Losses Fair Value U.S. treasury securities ​ $ 247,287 ​ $ — ​ $ (520) ​ $ 246,767 U.S. government agency securities ​ 5,104 ​ — ​ (7) ​ 5,097 Corporate securities ​ ​ 35,627 ​ ​ — ​ ​ (39) ​ ​ 35,588 Commercial paper ​ ​ 235,352 ​ ​ 10 ​ ​ (46) ​ ​ 235,316 Money market funds ​ ​ 56,250 ​ ​ — ​ ​ — ​ ​ 56,250 Total investments ​ $ 579,620 ​ $ 10 ​ $ (612) ​ $ 579,018
Schedule of available-for-sale debt securities	The fair value of cash equivalents and investments as of March 31, 2022 and December 31, 2021 are classified as follows in the Company’s Consolidated Balance Sheets (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, Classified as: ​ 2022 2021 Cash equivalents ​ $ 71,673 ​ $ 61,249 Short-term investments ​ ​ 389,829 ​ ​ 426,181 Long-term investments ​ ​ 27,701 ​ ​ 91,588 Total investments ​ $ 489,203 ​ $ 579,018
Schedule of available-for-sale debt securities by contractual maturity	The following table summarizes the Company’s cash equivalents and available-for-sale investments by contractual maturity (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2022 ​ ​ Amortized Cost Fair Value Within one year ​ $ 463,385 ​ $ 461,502 One year to two years ​ ​ 28,161 ​ ​ 27,701 Total investments ​ $ 491,546 ​ $ 489,203
Schedule of fair value of the company's financial assets	As of March 31, 2022 and December 31, 2021, the fair value of the Company’s financial assets that are measured at fair value on a recurring basis, which consist of cash equivalents and short-term and long-term investments classified as available-for-sale securities, are categorized in the table below based upon the lowest level of significant input to the valuations (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets at Fair Value as of March 31, 2022 ​ Level 1 Level 2 Level 3 Total U.S. treasury securities ​ $ 246,484 ​ $ — ​ $ — ​ $ 246,484 U.S. government agency securities ​ — ​ 5,046 ​ — ​ 5,046 Corporate securities ​ ​ — ​ ​ 34,329 ​ ​ — ​ ​ 34,329 Commercial paper ​ ​ — ​ ​ 158,095 ​ ​ — ​ ​ 158,095 Money market funds ​ ​ 45,249 ​ ​ — ​ ​ — ​ ​ 45,249 Total ​ $ 291,733 ​ $ 197,470 ​ $ — ​ $ 489,203 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets at Fair Value as of December 31, 2021 ​ Level 1 Level 2 Level 3 Total U.S. treasury securities ​ $ 246,767 ​ $ — ​ $ — ​ $ 246,767 U.S. government agency securities ​ — ​ 5,097 ​ — ​ 5,097 Corporate securities ​ ​ — ​ ​ 35,588 ​ ​ — ​ ​ 35,588 Commercial paper ​ ​ — ​ ​ 235,316 ​ ​ — ​ ​ 235,316 Money market funds ​ ​ 56,250 ​ ​ — ​ ​ — ​ ​ 56,250 Total ​ $ 303,017 ​ $ 276,001 ​ $ — ​ $ 579,018

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	3 Months Ended
	Mar. 31, 2022
PROPERTY AND EQUIPMENT, NET
Schedule of Property and equipment	Property and equipment, net consists of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ 2022 2021 Leasehold improvements ​ $ 65,767 ​ $ 57,817 Lab, process, and validation equipment ​ ​ 9,173 ​ ​ 8,686 Utility equipment ​ 4,179 ​ 4,179 Office furniture and equipment ​ 2,136 ​ 1,244 Computer software ​ ​ 6,264 ​ ​ 1,163 Computer equipment ​ 674 ​ 674 Machinery and equipment ​ ​ 82 ​ ​ 82 Construction in progress ​ 23,732 ​ 35,782 Total Property and equipment, cost ​ 112,007 ​ 109,627 Less: Accumulated depreciation and amortization ​ (9,250) ​ (8,689) Property and equipment, net ​ $ 102,757 ​ $ 100,938

ACCRUED EXPENSES (Tables)

ACCRUED EXPENSES (Tables)	3 Months Ended
	Mar. 31, 2022
ACCRUED EXPENSES
Schedule of accrued expenses	Accrued expenses consist of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ ​ 2022 2021 Accrued payroll and employee related expenses ​ $ 18,204 ​ $ 21,513 Clinical related ​ ​ 17,910 ​ ​ 18,167 Manufacturing related ​ 6,295 ​ 6,566 Facilities related ​ ​ 2,077 ​ ​ 4,857 Legal and related services ​ 1,654 ​ 1,907 Other accrued expenses ​ 2,771 ​ 3,756 Total accrued expenses ​ $ 48,911 ​ $ 56,766

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2022
STOCKHOLDERS' EQUITY
Schedule of status of stock options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ Weighted ​ Average ​ Aggregate ​ ​ Number ​ Average ​ Remaining ​ Intrinsic ​ ​ of ​ Exercise ​ Contract ​ Value ​ Options Price Life (in thousands) Outstanding at December 31, 2021 ​ 12,520,865 $ 25.05 ​ ​ ​ ​ ​ Issued ​ 1,887,052 ​ 14.69 ​ ​ ​ ​ ​ Exercised ​ (163,579) ​ 8.65 ​ ​ ​ ​ ​ Expired/Cancelled ​ (142,812) ​ 29.52 ​ ​ ​ ​ ​ Outstanding at March 31, 2022 ​ 14,101,526 $ 23.81 7.83 ​ $ 27,587 Ending vested and expected to vest at March 31, 2022 ​ 14,101,526 ​ $ 23.81 ​ 7.83 ​ $ 27,587 Options exercisable at March 31, 2022 7,543,738 ​ $ 20.50 6.74 ​ $ 23,859
Schedule of summary of RSU activity including PRSUs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ Number ​ Average ​ ​ of ​ Grant Date ​ RSUs and PRSUs Fair Value Outstanding, non-vested as of December 31, 2021 ​ 1,110,010 ​ $ 23.87 Granted ​ 2,027,774 ​ ​ 15.18 Canceled/Forfeited ​ (42,607) ​ ​ 19.43 Outstanding, non-vested as of March 31, 2022 ​ 3,095,177 ​ $ 18.24
Schedule of stock-based compensation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2022 2021 Research and development ​ $ 13,651 ​ $ 9,202 General and administrative ​ 8,614 ​ 7,739 Total stock-based compensation expense ​ $ 22,265 ​ $ 16,941
Schedule of compensation cost for share-based payment arrangements, allocation of share-based compensation costs by plan	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ 2022 2021 Stock option expense ​ $ 14,867 ​ $ 16,660 Restricted stock expense ​ 7,162 ​ — ESPP expense ​ 236 ​ 281 Total stock-based compensation expense ​ $ 22,265 ​ $ 16,941

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2022
LEASES
Schedule of balance sheet classification of the Company's right-of-use asset and lease liabilities	The balance sheet classification of the Company’s right-of-use asset and lease liabilities was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2022 ​ 2021 Operating lease right-of-use assets ​ $ 73,475 ​ $ 68,983 Operating lease liabilities ​ ​ ​ ​ ​ Current portion included in current liabilities ​ ​ 7,710 ​ 5,057 Long-term portion included in non-current liabilities ​ ​ 71,184 ​ 65,474 Total operating lease liabilities ​ $ 78,894 ​ $ 70,531
Schedule of components of lease expenses	The following table summarizes components of lease expenses, which were included in Total costs and expenses in the Company’s Condensed Consolidated Statements of Operations, and other information related to its operating leases as follows (in thousands except weighted-average remaining lease terms and discount rates): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ March 31, ​ ​ 2022 ​ 2021 Operating lease cost ​ $ 4,555 ​ $ 3,398 ​ Variable lease cost ​ 980 ​ 710 ​ Short-term lease cost ​ 42 ​ 36 ​ Total lease cost ​ $ 5,577 ​ $ 4,144 ​ ​ ​ ​ ​ ​ ​ ​ ​ Other information ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in the measurement of lease liabilities included in Operating cash flows ​ $ 3,811 ​ $ 2,466 ​ Tenant improvement allowance received for amounts included in the measurement of lease liabilities included in Operating cash flows ​ $ 3,115 ​ $ 144 ​ Right-of-use assets obtained from entering new leases ​ $ — ​ $ 618 ​ Increase in right-of-use assets from lease modifications ​ $ 7,673 ​ $ 2,159 ​ Weighted-average remaining lease terms (years) ​ ​ 14.13 ​ ​ 17.55 ​ Weighted-average discount rates ​ ​ 7.2% ​ ​ 7.4% ​
Schedule of minimum lease commitments	As of March 31, 2022, the maturities of the Company’s operating lease liabilities were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CMO ​ ​ ​ ​ Facility ​ embedded ​ ​ ​ Year Ending December 31, ​ leases leases Total 2022 ​ $ 4,332 ​ $ 6,317 ​ $ 10,648 2023 ​ 8,015 ​ 3,120 ​ 11,135 2024 ​ 8,215 ​ — ​ 8,215 2025 ​ 8,116 ​ — ​ 8,116 2026 ​ 7,989 ​ — ​ 7,989 Thereafter ​ 92,013 ​ — ​ 92,013 Total lease payments ​ $ 128,678 ​ $ 9,437 ​ $ 138,115 Less: Present value adjustment ​ (55,300) ​ (425) ​ (55,725) Future tenant improvement reimbursement ​ ​ (3,496) ​ ​ — ​ ​ (3,496) Operating lease liabilities ​ $ 69,883 ​ $ 9,012 ​ $ 78,894

GENERAL ORGANIZATION, BUSINES_2

GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY
Net loss	$ (91,607)	$ (75,449)
Net cash used in operating activities	(73,802)	(62,391)
Cash equivalents, short-term investments, and restricted cash	516,000
Cash and cash equivalents	92,360	131,954	$ 78,229
Short-term investments	389,829		426,181
Long-term investments	27,701		91,588
Restricted cash	$ 6,084	$ 6,084	$ 6,084

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash, Cash equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Cash and cash equivalents	$ 92,360	$ 78,229	$ 131,954
Restricted cash	6,084	6,084	6,084
Total cash, cash equivalents and restricted cash	98,444	$ 84,313	$ 138,038	$ 72,854
Commercial manufacturing facility
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Security deposit	5,450
Decrease in letters of credit	1,000
Commercial manufacturing facility | Minimum
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Security deposit	1,500
Utilities service provider
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Security deposit	100
Headquarters lease
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Security deposit	$ 600

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Net Loss per Share (Details) - shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Antidilutive securities excluded from calculation of net loss per share	20,222,309	18,414,347
Stock option
Antidilutive securities excluded from calculation of net loss per share	14,101,526	15,419,226
Employee Stock Purchase Plan
Antidilutive securities excluded from calculation of net loss per share	86,448	55,963
Restricted stock units
Antidilutive securities excluded from calculation of net loss per share	3,095,177
Series A Convertible Preferred Stock
Antidilutive securities excluded from calculation of net loss per share	97,000	97,000
Series B Convertible Preferred Stock
Antidilutive securities excluded from calculation of net loss per share	2,842,158	2,842,158

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional information (Details)	3 Months Ended
	Mar. 31, 2022segment
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Number of operating segments	1

CASH EQUIVALENTS, INVESTMENTS_3

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS - Cost and fair value (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Amortized Cost	$ 491,546	$ 579,620
Gross Unrealized Gains	1	10
Gross Unrealized Losses	(2,344)	(612)
Fair Value	489,203	579,018
U.S. treasury securities
Amortized Cost	248,546	247,287
Gross Unrealized Losses	(2,062)	(520)
Fair Value	246,484	246,767
U.S. government agency securities
Amortized Cost	5,067	5,104
Gross Unrealized Losses	(21)	(7)
Fair Value	5,046	5,097
Corporate securities
Amortized Cost	34,408	35,627
Gross Unrealized Losses	(79)	(39)
Fair Value	34,329	35,588
Commercial paper
Amortized Cost	158,276	235,352
Gross Unrealized Gains	1	10
Gross Unrealized Losses	(182)	(46)
Fair Value	158,095	235,316
Money market funds
Amortized Cost	45,249	56,250
Fair Value	$ 45,249	$ 56,250

CASH EQUIVALENTS, INVESTMENTS_4

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS - Available for sale debt securities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents [Line Items]
Short-term investments	$ 389,829	$ 426,181
Long-term investments	27,701	91,588
Total investments	489,203	579,018
Money market funds
Cash and Cash Equivalents [Line Items]
Cash equivalents	$ 71,673	$ 61,249

CASH EQUIVALENTS, INVESTMENTS_5

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)
Unrealized losses on available-for-sale	$ 0	$ 0
Number of investments in debt securities in continuous unrealized loss position for more than 12 months	0
Money market funds
Cash equivalents total	$ 71,673	61,249
Demand Deposits
Cash equivalents total	$ 20,700	$ 17,000

CASH EQUIVALENTS, INVESTMENTS_6

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS - Contractual maturity (Details) $ in Thousands	Mar. 31, 2022USD ($)
Amortized Cost
Within one year	$ 463,385
One year to two years	28,161
Amortized cost investments total	491,546
Fair Value
Within one year	461,502
One year to two years	27,701
Total investments	$ 489,203

CASH EQUIVALENTS, INVESTMENTS_7

CASH EQUIVALENTS, INVESTMENTS AND FAIR VALUE MEASUREMENTS - Fair value of company's financial assets (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Total	$ 489,203	$ 579,018
U.S. treasury securities
Total	246,484	246,767
U.S. government agency securities
Total	5,046	5,097
Corporate securities
Total	34,329	35,588
Commercial paper
Total	158,095	235,316
Money market funds
Total	45,249	56,250
Level 1
Total	291,733	303,017
Level 1 | U.S. treasury securities
Total	246,484	246,767
Level 1 | Money market funds
Total	45,249	56,250
Level 2
Total	197,470	276,001
Level 2 | U.S. government agency securities
Total	5,046	5,097
Level 2 | Corporate securities
Total	34,329	35,588
Level 2 | Commercial paper
Total	$ 158,095	$ 235,316

PROPERTY AND EQUIPMENT, NET - (

PROPERTY AND EQUIPMENT, NET - (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 112,007	$ 109,627
Less: Accumulated depreciation and amortization	(9,250)	(8,689)
Property and equipment, net	102,757	100,938
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	65,767	57,817
Lab, process, and validation equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	9,173	8,686
Utility equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	4,179	4,179
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	2,136	1,244
Computer software
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	6,264	1,163
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	674	674
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	82	82
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment, cost	$ 23,732	$ 35,782

PROPERTY AND EQUIPMENT, NET - O

PROPERTY AND EQUIPMENT, NET - Other information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
PROPERTY AND EQUIPMENT, NET
Depreciation	$ 1.8	$ 0.4

ACCRUED EXPENSES (Details)

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
ACCRUED EXPENSES
Accrued payroll and employee related expenses	$ 18,204	$ 21,513
Clinical related	17,910	18,167
Manufacturing related	6,295	6,566
Facilities related	2,077	4,857
Legal and related services	1,654	1,907
Other accrued expenses	2,771	3,756
Total accrued expenses	$ 48,911	$ 56,766

STOCKHOLDERS' EQUITY (Details)

STOCKHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Thousands	Feb. 08, 2021	Jun. 08, 2020	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Jan. 12, 2022	Jan. 11, 2022	Dec. 31, 2021	Sep. 22, 2021	Jun. 07, 2020	Apr. 22, 2018
Common Stock
Common stock, shares authorized			300,000,000		300,000,000			300,000,000
Common stock, par or stated value per share			$ 0.000041666		$ 0.000041666			$ 0.000041666
Common stock, shares issued			157,168,321		157,168,321			157,004,742
Common stock, shares outstanding			157,168,321		157,168,321			157,004,742
Proceeds from the issuance of common stock, net			$ 0	$ 42,885
Weighted average grant date fair value, options granted			$ 8.81	$ 26.42
Common Stock
Common Stock
Common stock issued, net of offering costs (in shares)				1,278,243
Common Stock | Issuance Of Common Stock Upon Conversion Of Preferred Stock
Common Stock
Conversion of stock, shares issued				738,961
At the Market Offering Program
Common Stock
Maximum amount of shares to be issued	$ 350,000
Maximum percentage of commission	3.00%
Common stock issued, net of offering costs (in shares)			0	1,278,243
Proceeds from the issuance of common stock, net				$ 42,900
Weighted average price				$ 34.67
Series A Convertible Preferred Stock
Common Stock
Preferred stock, shares authorized			17,000		17,000			17,000
Preferred stock, par or stated value per share			$ 0.001		$ 0.001			$ 0.001
Conversion of Stock, shares converted			0	0
Conversion of stock, shares issued			500
Preferred stock, shares outstanding			194		194			194
Series A Convertible Preferred Stock | Common Stock
Common Stock
Common stock available in conversion, shares			97,000		97,000			97,000
Series A Convertible Preferred Stock | Private Placement
Common Stock
Preferred stock, par or stated value per share			$ 1,000		$ 1,000
Convertible price per share			$ 2
Series B Convertible Preferred Stock
Common Stock
Preferred stock, shares authorized			11,500,000		11,500,000			11,500,000
Preferred stock, par or stated value per share			$ 0.001		$ 0.001			$ 0.001
Conversion of stock, shares issued			1
Preferred stock, shares outstanding			2,842,158		2,842,158			2,842,158
Series B Convertible Preferred Stock | Issuance Of Common Stock Upon Conversion Of Preferred Stock
Common Stock
Conversion of stock, shares issued			0	738,961
Series B Convertible Preferred Stock | Common Stock
Common Stock
Preferred stock, shares outstanding			2,842,158		2,842,158			2,842,158
Series B Convertible Preferred Stock | IPO
Common Stock
Preferred stock, par or stated value per share			$ 4.75		$ 4.75
Convertible price per share			$ 4.75
Blank check
Common Stock
Preferred stock, shares authorized			50,000,000		50,000,000
Stock option
Common Stock
Unrecognized compensation cost			$ 94,100		$ 94,100
Unrecognized compensation cost recognition period			1 year 11 months 19 days
RSUs and PRSUs
Common Stock
Unrecognized compensation cost recognition period			1 year 10 months 17 days
Unrecognized compensation cost			$ 37,000		37,000
Aggregate intrinsic value of outstanding non-vested RSUs & PRSUs			$ 51,500		$ 51,500
2014 Equity Incentive Plan
Common Stock
Number of shares available			79,465		79,465
The 2018 Plan
Common Stock
Number of shares available			1,058,461		1,058,461
Shares authorized		14,000,000								6,000,000	6,000,000
2020 ESPP
Common Stock
Common stock issued, net of offering costs (in shares)					94,148
Shares authorized		500,000
Percentage of purchase price		85.00%
Stock-based compensation expense			$ 200	$ 300
Unrecognized compensation cost			$ 200		$ 200
Unrecognized compensation cost recognition period			2 months 9 days
2021 Inducement Plan
Common Stock
Number of shares available			552,925		552,925
Shares authorized						1,750,000	1,000,000		1,000,000

STOCKHOLDERS' EQUITY - Stock Op

STOCKHOLDERS' EQUITY - Stock Options (Details) - Stock option $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)$ / sharesshares
Number of Options
Outstanding, beginning balance | shares	12,520,865
Issued | shares	1,887,052
Exercised | shares	(163,579)
Expired/Forfeited | shares	(142,812)
Outstanding, ending balance | shares	14,101,526
Ending vested and expected to vest | shares	14,101,526
Options exercisable | shares	7,543,738
Weighted Average Exercise Price
Outstanding, beginning balance | $ / shares	$ 25.05
Issued | $ / shares	14.69
Exercised | $ / shares	8.65
Expired/Forfeited | $ / shares	29.52
Outstanding, ending balance | $ / shares	23.81
Ending vested and expected to vest | $ / shares	23.81
Options exercisable | $ / shares	$ 20.50
Weighted Average Remaining Contractual Life
Options outstanding, remaining term	7 years 9 months 29 days
Ending vested and expected to vest, remaining term	7 years 9 months 29 days
Options exercisable, remaining term	6 years 8 months 26 days
Aggregate Intrinsic Value
Option at ending balance | $	$ 27,587
Ending vested and expected to vest | $	27,587
Option exercisable | $	$ 23,859

STOCKHOLDERS' EQUITY - Restrict

STOCKHOLDERS' EQUITY - Restricted Stock Units and Performance Restricted Stock Units (Details) - RSUs and PRSUs	3 Months Ended
	Mar. 31, 2022$ / sharesshares
Number of Shares
Non-vested shares, Beginning Balance | shares	1,110,010
Granted | shares	2,027,774
Canceled/forfeited | shares	(42,607)
Non-vested shares, Ending balance | shares	3,095,177
Weighted Average Grant Date Fair Value
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 23.87
Weighted Average Grant Date Fair Value, Granted | $ / shares	15.18
Weighted Average Grant Date Fair Value, Canceled/forfeited | $ / shares	19.43
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 18.24

STOCKHOLDERS' EQUITY - Stock ba

STOCKHOLDERS' EQUITY - Stock based expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total stock-based compensation expenses	$ 22,265	$ 16,941
Research and development
Total stock-based compensation expenses	13,651	9,202
General and administrative
Total stock-based compensation expenses	$ 8,614	$ 7,739

STOCKHOLDERS' EQUITY - Stock-ba

STOCKHOLDERS' EQUITY - Stock-based compensation by instrument (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total stock-based compensation expenses	$ 22,265	$ 16,941
Stock option
Total stock-based compensation expenses	14,867	16,660
Restricted stock units
Total stock-based compensation expenses	7,162
2020 ESPP
Total stock-based compensation expenses	$ 236	$ 281

LICENSES AND AGREEMENTS (Detail

LICENSES AND AGREEMENTS (Details) $ in Thousands	May 07, 2018USD ($)	Apr. 17, 2017USD ($)	Jun. 28, 2014USD ($)	Aug. 31, 2021USD ($)	Nov. 30, 2016item	Aug. 31, 2011	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Research and development expenses							$ 68,300	$ 55,949
Maximum | Strategic Alliance Agreement
Research and development arrangement, contract to perform for others, costs incurred, gross		$ 14,200
Research and development | Strategic Alliance Agreement
Research and development arrangement, contract to perform for others, costs incurred, gross							7,000
Cooperative Research and Development Agreement
Agreement term				3 years		5 years
Research and development expenses				$ 500			500	500
Notification Period To Terminate Agreement				60 days
Research Collaboration And Clinical Grant Agreements With Moffitt
Research and development expenses							100	200
Moffitt License Agreement One
Agreement term			20 years
Research and development expenses							0	0
Moffitt License Agreement One | Research and development
Payments for upfront licensing fee			$ 100
Moffitt License Agreement Two
Payments for upfront licensing fee	$ 100
Additional milestone payable							400
Moffitt License Agreement Two, Amended and Restated
Payments for upfront licensing fee									$ 200
WuXi Apptech, Inc - Manufacturing and Services Agreement
Agreement term					3 years
Research and development expenses							3,900	3,400
Number Of Statements Of Work | item					2
Number Of Suites Under The Agreement | item					2
Cellectis S.A
Research and development expenses							100	100
Novartis Pharma AG - License Agreement
Research and development expenses							$ 0	$ 0		$ 10,000

LEASES - Additional information

LEASES - Additional information (Details) $ in Thousands	3 Months Ended		15 Months Ended
	Mar. 31, 2022USD ($)ft²	Mar. 31, 2021USD ($)	Mar. 31, 2022USD ($)ft²	Dec. 31, 2021USD ($)
Option to extend	true
Monthly lease payments	$ 138,115		$ 138,115
First year	11,135		11,135
Second year	8,215		8,215
Monthly lease payments	3,811	$ 2,466
Operating lease liabilities	78,894		78,894	$ 70,531
Operating lease right-of-use assets	73,475		$ 73,475	$ 68,983
Tenant improvement allowance	8,200
Tenant improvement allowance reimbursed	$ 3,115	$ 144
Minimum
Term of contract in years	1 year		1 year
Maximum
Term of contract in years	20 years		20 years
Office Space | Minimum
Term of contract in years	12 months		12 months
Office Space | Philadelphia, Pennsylvania
Area of property | ft²	136,000		136,000
Furniture and equipment | Maximum
Term of contract in years	12 months		12 months
Facility leases
Monthly lease payments	$ 128,678		$ 128,678
First year	8,015		8,015
Second year	8,215		8,215
Operating lease liabilities	$ 69,883		$ 69,883
New Headquarters Lease | Office Space | San Carlos, California
Area of property | ft²	49,918		49,918
Tenant improvement allowance reimbursed	$ 3,100		$ 4,700

LEASES - Right-of-use asset and

LEASES - Right-of-use asset and lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
LEASES
Operating lease right-of-use assets	$ 73,475	$ 68,983
Operating lease liabilities
Current portion included in current liabilities	7,710	5,057
Long-term portion included in non-current liabilities	71,184	65,474
Total operating lease liabilities	$ 78,894	$ 70,531

LEASES - Components of lease ex

LEASES - Components of lease expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
LEASES
Operating lease cost	$ 4,555	$ 3,398
Variable lease cost	980	710
Short-term lease cost	42	36
Total lease cost	5,577	4,144
Cash paid for amounts included in the measurement of lease liabilities included in operating cashflows	3,811	2,466
Tenant improvement allowance received for amounts included in the measurement of lease liabilities included in Operating cash flows	3,115	144
Right-of-use assets obtained from entering new leases		618
Increase in right-of-use assets from lease modifications	$ 7,673	$ 2,159
Weighted-average remaining lease terms (years)	14 years 1 month 17 days	17 years 6 months 18 days
Weighted-average discount rates	7.20%	7.40%

LEASES - Maturities of the Comp

LEASES - Maturities of the Company's operating lease liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
2022	$ 10,648
2023	11,135
2024	8,215
2025	8,116
2026	7,989
Thereafter	92,013
Total lease payments	138,115
Less: Present value adjustment	(55,725)
Future tenant improvement reimbursement	(3,496)
Operating lease liabilities	78,894	$ 70,531
Facility leases
2022	4,332
2023	8,015
2024	8,215
2025	8,116
2026	7,989
Thereafter	92,013
Total lease payments	128,678
Less: Present value adjustment	(55,300)
Future tenant improvement reimbursement	(3,496)
Operating lease liabilities	69,883
CMO embedded leases
2022	6,317
2023	3,120
Total lease payments	9,437
Less: Present value adjustment	(425)
Operating lease liabilities	$ 9,012

LEGAL PROCEEDINGS (Details)

LEGAL PROCEEDINGS (Details) - Solomon Capital LLC Litigation	May 12, 2020USD ($)	Jun. 03, 2016USD ($)	Apr. 08, 2016USD ($)	Mar. 31, 2013	Nov. 30, 2012USD ($)	Jun. 30, 2012USD ($)
Damages claimed		$ 500,000
Equity claim	$ 47,420
Proceeds from lawsuit filed					$ 200,000	$ 100,000
Debt instrument, convertible, number of equity instruments			1,110
Reverse split ratio				0.01
Minimum
Estimate of possible loss			$ 1,500,000
Commercial paper
Face amount			$ 200,000