0001558370-21-001858 | 10-K | XBRL Viewer | Iovance Biotherapeutics INC

Document And Entity Information - USD ($) $ in Billions	12 Months Ended
Document And Entity Information - USD ($) $ in Billions	Dec. 31, 2020	Feb. 17, 2021	Jun. 30, 2020
Document And Entity Information [Abstract]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
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	999 Skyway Road, Suite 150
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, $ 0.000041666 Par Value per Share
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		146,979,253
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Central Index Key	0001425205
Amendment Flag	false
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 3.7

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 67,329	$ 13,969
Short-term investments	562,108	293,112
Prepaid expenses and other assets	6,663	9,412
Total Current Assets	636,100	316,493
Property and equipment, net	59,159	8,536
Operating lease right-of-use assets	54,756	10,695
Restricted cash	5,525	5,450
Long-term assets	12,918	3,481
Total Assets	768,458	344,655
Current Liabilities
Accounts payable	13,513	15,567
Accrued expenses	35,074	16,265
Operating lease liabilities - current	6,284	7,252
Total Current Liabilities	54,871	39,084
Non-Current Liabilities
Operating lease liabilities - noncurrent	45,375	4,248
Other liabilities	11,714	2,352
Total Non-Current Liabilities	57,089	6,600
Total Liabilities	111,960	45,684
Commitments and contingencies (Note 10 and 11)
Stockholders' Equity
Common stock, $0.000041666 par value; 300,000,000 shares authorized, 146,874,917 and 126,411,808 shares issued and outstanding as of December 31, 2020 and December 31, 2019, respectively	6	5
Accumulated other comprehensive income	19	220
Additional paid-in capital	1,486,662	869,354
Accumulated deficit	(830,193)	(570,612)
Total Stockholders' Equity	656,498	298,971
Total Liabilities and Stockholders' Equity	768,458	344,655
Series B Convertible Preferred Stock
Stockholders' Equity
Preferred stock, Value	4	4
Total Stockholders' Equity	$ 4	$ 4

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
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	146,874,917	126,411,808
Common Stock, Shares, Outstanding	146,874,917	126,411,808
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
Preferred Stock, Liquidation Preference, Value	$ 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	3,581,119	3,581,119
Preferred stock, shares outstanding	3,581,119	3,581,119
Preferred Stock, Liquidation Preference, Value	$ 17,010	$ 17,010

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Costs and expenses
Research and development expenses	$ 201,727	$ 166,023	$ 99,828
General and administrative expenses	60,210	40,849	28,430
Total costs and expenses	261,937	206,872	128,258
Loss from operations	(261,937)	(206,872)	(128,258)
Other income
Interest income, net	2,356	9,316	4,678
Net Loss	$ (259,581)	$ (197,556)	$ (123,580)
Net Loss Per Share of Common Stock, Basic and Diluted	$ (1.88)	$ (1.59)	$ (1.27)
Weighted Average Shares of Common Stock Outstanding, Basic and Diluted	138,301	124,336	97,277

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Consolidated Statements of Comprehensive Loss
Net Loss	$ (259,581)	$ (197,556)	$ (123,580)
Other comprehensive loss:
Unrealized (loss) / gain on short-term investments	(201)	262	(42)
Comprehensive Loss	$ (259,782)	$ (197,294)	$ (123,622)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Consolidated Statements of Stockholders' Equity - USD ($)	Series A Convertible Preferred Stock	Series B Convertible Preferred Stock	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-In Capital	Cumulative Effect, Period of Adoption, Adjustment [Member] Accumulated Deficit	Common Stock	Additional Paid-In Capital	Accumulated other Comprehensive Income	Accumulated Deficit	Total
Beginning Balance at Dec. 31, 2017		$ 7,000			$ 3,000	$ 394,651,000		$ (249,180,000)	$ 145,481,000
Beginning Balance (in Shares) at Dec. 31, 2017	1,694	7,378,241			73,164,914
Stock-based compensation expense						20,027,000			20,027,000
Vesting of restricted shares issued for services (in shares)					39,536
Tax payments related to shares withheld for vested restricted stock units						(223,000)			(223,000)
Common stock issued upon exercise of warrants					$ 1,000	15,753,000			15,754,000
Common stock issued upon exercise of warrants (in Shares)					6,301,216
Common stock issued upon exercise of stock options						9,959,000			$ 9,959,000
Common stock issued upon exercise of stock options (in shares)					1,336,514				1,336,514
Unrealized (loss) / gain on short-term investments							$ (42,000)		$ (42,000)
Common stock sold in public offering, net of offering costs					$ 1,000	398,816,000			398,817,000
Common stock sold in public offering, net of offering costs (in shares)					40,300,000
Conversion of convertible preferred stock into common stock	$ (1,500)	$ (1,000)				1,000
Conversion of convertible preferred stock into common stock (in Shares)		(1,523,396)			2,273,396
Net loss								(123,580,000)	(123,580,000)
Ending Balance at Dec. 31, 2018		$ 6,000			$ 5,000	838,984,000	(42,000)	(372,760,000)	466,193,000
Ending Balance (in Shares) at Dec. 31, 2018	194	5,854,845			123,415,576
Stock-based compensation expense						24,277,000			24,277,000
Vesting of restricted shares issued for services					$ 1,000	(1,000)
Vesting of restricted shares issued for services (in shares)					27,514
Tax payments related to shares withheld for vested restricted stock units						(312,000)			(312,000)
Common stock issued upon exercise of stock options						6,443,000			$ 6,443,000
Common stock issued upon exercise of stock options (in shares)					727,492				727,492
Unrealized (loss) / gain on short-term investments							262,000		$ 262,000
Conversion of convertible preferred stock into common stock		$ (2,000)				2,000
Conversion of convertible preferred stock into common stock (in Shares)		(2,273,726)			2,273,726
Cancellation of common shares from settlement of dispute					$ (1,000)	(335,000)			(336,000)
Cancellation of common shares from settlement of dispute (In Shares)					(32,500)
Net loss								(197,556,000)	(197,556,000)
Ending Balance at Dec. 31, 2019		$ 4,000			$ 5,000	869,354,000	220,000	(570,612,000)	298,971,000
Ending Balance (in Shares) at Dec. 31, 2019	194	3,581,119			126,411,808
Adoption of ASU 2018-07			$ 296,000	$ (296,000)
Stock-based compensation expense						40,775,000			40,775,000
Vesting of restricted shares issued for services						112,000			112,000
Vesting of restricted shares issued for services (in shares)					13,449
Tax payments related to shares withheld for vested restricted stock units						(284,000)			(284,000)
Common stock issued upon exercise of stock options						9,663,000			$ 9,663,000
Common stock issued upon exercise of stock options (in shares)					973,854				973,854
Unrealized (loss) / gain on short-term investments							(201,000)		$ (201,000)
Common stock sold in public offering, net of offering costs					$ 1,000	567,042,000			567,043,000
Common stock sold in public offering, net of offering costs (in shares)					19,475,806
Net loss								(259,581,000)	(259,581,000)
Ending Balance at Dec. 31, 2020		$ 4,000			$ 6,000	$ 1,486,662,000	$ 19,000	$ (830,193,000)	$ 656,498,000
Ending Balance (in Shares) at Dec. 31, 2020	194	3,581,119			146,874,917

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities
Net loss	$ (259,581)	$ (197,556)	$ (123,580)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	40,887	24,277	20,027
Noncash lease expense	7,572	6,954
Depreciation and amortization	1,140	1,169	956
Gain on settlement of dispute		(336)
Accretion (amortization) of discounts and premiums on investments	1,865	(3,421)	(1,332)
Loss on disposal of assets		16	9
Changes in assets and liabilities:
Prepaid expenses, other assets, and long-term assets	(6,688)	(3,278)	(2,065)
Operating lease liabilities (Right-of-use assets)	(11,474)	(6,148)
Accounts payable	(2,964)	12,706	1,507
Accrued expenses and other liabilities	24,109	6,728	3,229
Net cash used in operating activities	(205,134)	(158,889)	(101,249)
Cash Flows from Investing Activities
Maturities of short-term investments	676,601	514,601	41,000
Purchase of short-term investments	(947,663)	(417,659)	(426,081)
Purchase of property and equipment	(46,791)	(6,917)	(1,198)
Net cash (used in) provided by investing activities	(317,853)	90,025	(386,279)
Cash Flows from Financing Activities
Tax payments related to shares withheld for vested restricted stock units	(284)	(312)	(223)
Proceeds from the issuance of common stock upon exercise of warrants			15,754
Proceeds from the issuance of common stock upon exercise of options	9,663	6,443	9,959
Proceeds from the issuance of common stock, net	567,043		398,817
Net cash provided by financing activities	576,422	6,131	424,307
Net increase (decrease) in cash, cash equivalents, and restricted cash	53,435	(62,733)	(63,221)
Cash, Cash Equivalents, and Restricted Cash Beginning of Year	19,419	82,152	145,373
Cash, Cash Equivalents, and Restricted Cash End of Year	72,854	19,419	82,152
Supplemental disclosure of non-cash investing and financing activities:
Net unrealized (loss) gain on short-term investments	(201)	262	(42)
Acquisitions of property and equipment included in accounts payable and accrued expense	$ (5,094)	122
Conversion of convertible preferred stock to common stock		2	$ 1
Vesting of restricted stock units		$ 1

GENERAL ORGANIZATION AND BUSINESS

12 Months Ended

Dec. 31, 2020

GENERAL ORGANIZATION AND BUSINESS

GENERAL ORGANIZATION AND BUSINESS

NOTE 1. GENERAL ORGANIZATION, BUSINESS AND LIQUIDITY

General Organization and Business

Iovance Biotherapeutics, Inc. (the “Company”, “we”, “us” or “our”) is a clinical-stage biopharmaceutical company focused on the development and commercialization of cell therapies as novel cancer immunotherapy products designed to harness the power of a patient’s own immune system to eradicate cancer cells. 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. The Company has developed a new, shorter manufacturing process for TIL therapy known as Generation 2 (“Gen 2”), which yields a cryopreserved TIL product. This proprietary and scalable manufacturing method is being further investigated in multiple indications. The Company’s lead product candidates include lifileucel for metastatic melanoma and metastatic cervical cancer. Lifileucel for metastatic cervical cancer was formerly known as LN-145. In addition to metastatic melanoma and metastatic cervical cancer, the Company is investigating the effectiveness and safety of TIL therapy and peripheral blood lymphocyte therapy for the treatment of squamous cell carcinoma of the head and neck, non-small cell lung cancer, and chronic lymphocytic leukemia through its sponsored trials, as well as in other oncology indications through collaborations. On June 1, 2017, the Company reincorporated from a Nevada corporation to a Delaware corporation.

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. The Company currently does not anticipate that it will generate any significant revenues from the sale or licensing of any of its product candidates during the 12 months from the date these financial statements are issued. The Company has incurred a net loss of $259.6 million for the year ended December 31, 2020 and used $205.1 million of cash in its operating activities during the year ended December 31, 2020. As of December 31, 2020, the Company had $635.0 million in cash, cash equivalents, short-term investments, and restricted cash ($67.3 million of cash and cash equivalents, $562.1 million in short-term investments and $5.5 million in restricted cash).

The Company expects to continue its research and development activities, increase pre-commercial activities and continue the construction of the tenant improvements for its new manufacturing facility, which will increase the amount of cash used during 2021 and beyond. Specifically, the Company expects continued spending on its current and planned clinical trials, continued expansion of manufacturing activities, including construction of a manufacturing facility, 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.

Impact of COVID-19

In December 2019, a novel coronavirus known as SARS-CoV-2 was first detected in Wuhan, Hubei Province, People’s Republic of China, causing outbreaks of the coronavirus disease, known as COVID-19, that has now spread globally. On January 30, 2020, the World Health Organization (“WHO”) declared COVID-19 a pandemic (the “COVID-19 Pandemic”). The Secretary of Health and Human Services declared a public health emergency on January 31, 2020, under section 319 of the Public Health Service Act (42 U.S.C. 247d), in response to the COVID-19 Pandemic. The full impact of the COVID-19 Pandemic is unknown and rapidly evolving. While the potential economic impact brought by and over the duration of the COVID-19 Pandemic may be difficult to assess or predict, the COVID-19 Pandemic has resulted in significant disruption of global financial markets, which could in the future negatively affect the Company's liquidity. In addition, a recession or market volatility resulting from the COVID-19 Pandemic could affect the Company’s business. Given the nature and type of the Company’s short-term investments in U.S. government securities, the Company does not believe the COVID-19 Pandemic has had or will have a material impact on the Company's current investment liquidity.

Concentrations of Risk

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, in order of priority, are as follows: safety and preservation of principal and diversification of risk and liquidity of investments sufficient to meet cash flow requirements.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

12 Months Ended

Dec. 31, 2020

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING PRACTICES

Cash, Cash Equivalents, and Short-term 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 short-term investments are classified as “available-for-sale.” The Company includes these investments in current assets and carries them at fair value. Unrealized gains and losses on available-for-sale securities are included in accumulated other comprehensive loss or income. Any impairment losses related to credit losses (if any) are included in an allowance for credit losses with an offsetting entry to net loss. No impairment losses related to credit losses were recognized for the years ended December 31, 2020 and 2019. 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 net interest income in the Consolidated Statements of Operations. Gains and losses on securities sold are recorded based on the specific identification method and are included in net interest income in the 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 places restrictions on maturities and concentration by type and issuer, except for securities issued by the U.S. government. Currently the Company invests excess cash only in obligations issued by the U.S. government and U.S. government agencies.

Restricted Cash

The Company maintains a certain minimum balance, approximately $5.5 million in a segregated bank account in connection with a letter of credit, one for $5.45 million for the benefit of the landlord for its commercial manufacturing facility used as a security deposit for the lease (See Note 10 - Leases), and a second one for $74,685 for the benefit of a utilities service provider. The total amount is classified as Restricted Cash on the Consolidated Balance Sheet. The letter of credit originally expired on May 28, 2020, however, it automatically extends for additional one-year periods, without written agreement, to May 28 in each succeeding calendar year, through at least 60 days after the lease expiration date. Further, on the expiration of the seventh year of the lease, and each anniversary date thereafter, the letter of credit may be decreased by $1,000,000, with a minimum security deposit of $1,450,000 maintained through the end of the lease term. The $74,685 letter of credit will expire on March 9, 2021, however, it will be automatically extended, without written agreement, to the expiration date of December 1, 2022. As of December 31, 2020 and 2019, restricted cash consisted of $5.5 million and this amount has been classified as a non-current asset on the Company’s Consolidated Balance Sheets.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash, reported within the Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows:


	December 31,		December 31,		December 31,
	2020		2019		2018

Cash and cash equivalents	$	67,329	$	13,969	$	82,152
Restricted cash (included in non-current assets on the Consolidated Balance Sheets)		5,525		5,450		—
Total cash, cash equivalents and restricted cash	$	72,854	$	19,419	$	82,152

Property and Equipment, net

Property and equipment is stated at cost, net of accumulated depreciation and amortization. The cost of property and equipment is depreciated or amortized on the straight-line method over the following estimated useful lives. The depreciation or amortization of capitalized construction in progress costs, a component of property and equipment, net, begins once the underlying asset is placed into service and is recognized over the estimated useful lives:

Computer equipment		2 years
Office furniture and equipment		5 years
Lab equipment		5 years
Leasehold improvements		Lesser of the remaining economic life of the asset or the lease-term

Expenditures for maintenance and repairs are charged to operations as incurred while renewals and betterments are capitalized. Gains and losses on disposals are included within operating expenses in the Consolidated Statements of Operations.

Management assesses the carrying value of property and equipment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. If there is indication of impairment, management prepares an estimate of future undiscounted cash flows expected to result from the use of the asset and its eventual disposition. If these cash flows are less than the carrying amount of the asset, an impairment loss is recognized to write down the asset to its estimated fair value. For the years ended December 31, 2020, 2019, and 2018, the Company did not recognize any impairments for its property and equipment.

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 equivalent shares 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 and warrants, (ii) purchases though the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), (iii) vesting of restricted stock units and restricted stock awards, and (vi) conversion of preferred stock, are only included in the calculation of diluted net loss per share when their effect is dilutive.

At December 31, 2020, 2019, and 2018, the following outstanding common stock equivalents have been excluded from the calculation of net loss per share because their impact would be anti-dilutive.


	As of December 31,
	2020	2019	2018
Stock options	12,615,638	9,494,712	6,889,287
Series A Convertible Preferred Stock*	97,000	97,000	97,000
Series B Convertible Preferred Stock*	3,581,119	3,581,119	5,854,845
2020 ESPP	37,259	—	—
Restricted stock units	—	22,916	68,742
	16,331,016	13,195,747	12,909,874

*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.

Fair Value Measurements

Under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 820, Fair Value Measurements and Disclosures, fair value is defined as the price at which an asset could be exchanged, or a liability transferred in a transaction between knowledgeable, willing parties in the principal or most advantageous market for the asset or liability. Where available, fair value is based on observable market prices or parameters or derived from such prices or parameters. Where observable prices or parameters are not available, valuation models are applied.

Assets and liabilities recorded at fair value in the Company’s financial statements are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels directly related to the amount of subjectivity associated with the inputs to fair valuation of these assets and liabilities, are as follows:

Level 1—These are investments where values are based on unadjusted quoted prices for identical assets in an active market that the Company has the ability to access.

Level 2—These are investments where values are based on quoted market prices in markets that are not active or model derived valuations in which all significant inputs are observable in active markets

The Company does not have fair valued assets classified under Level 2 as of December 31, 2020 and 2019.

Level 3—These are financial instruments where values are derived from techniques in which one or more significant inputs are unobservable.

The Company does not have fair valued assets classified under Level 3 as of December 31, 2020 and 2019.

The Company’s financial instruments consist of cash and cash equivalents and short-term investments, all of which are reported at their respective fair value on its Consolidated Balance Sheets.

As of December 31, 2020 and 2019, financial assets measured at fair value on a recurring basis 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 December 31, 2020
	Level 1		Level 2		Level 3		Total
U.S. treasury securities	$	470,109	$	—	$	—	$	470,109
U.S. government agency securities		91,999		—		—		91,999
Total	$	562,108	$	—	$	—	$	562,108


	Assets at Fair Value as of December 31, 2019
	Level 1		Level 2		Level 3		Total
US treasury securities	$	242,249	$	—	$	—	$	242,249
US government agency securities		50,863		—		—		50,863
Total	$	293,112	$	—	$	—	$	293,112

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“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 revenue and expenses during the reporting period. Actual results could differ from those estimates. Significant estimates include the assumptions made in valuing stock instruments issued for services and used in measuring operating right-of-use assets and operating lease liabilities, accounting for potential liabilities, capitalization of internal-use software development costs, and the valuation allowance associated with the Company’s deferred tax assets.

Principles of Consolidation

The accompanying consolidated financial statements include the accounts of Iovance Biotherapeutics, Inc. and its wholly-owned subsidiaries, Iovance Biotherapeutics Manufacturing LLC and Iovance Biotherapeutics GmbH. 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. Operating leases are included in its Consolidated Balance Sheet as Operating lease right-of-use assets and Operating lease liabilities as of December 31, 2020. 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 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 date or the date of adoption of Accounting Standard Update (ASU) No. 2016-02 and ASU No. 2018-10, Leases (together “Topic 842”). 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. The Company has elected not to apply the recognition requirements of Topic 842 for short-term leases.

For lease agreements entered into after the adoption of Topic 842 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 in non-capital raising transactions as compensation for services rendered. The Company also offers employee stock purchase plans to employees. The Company accounts for all stock-based payment awards made to employee, including the employee stock purchase plans, based on the authoritative guidance provided by the FASB where the value of the award is measured on the date of grant and recognized over the vesting period. Upon the adoption of ASU No. 2018-07, Compensation-Stock Compensation (“Topic 718”), 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 life 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 materially affect compensation expense recorded in future periods.

The Company has in the past issued restricted stock units (“RSU”) and restricted stock awards (“RSA”) as part of its share-based compensation programs. The Company measures the compensation cost with respect to RSUs and RSAs 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 and RSAs is based on the closing price of the Company’s common stock on the grant date.

Cloud Computing Arrangements

The Company defers implementation costs incurred in cloud computing arrangements in accordance with ASC 2018-15 and amortizes it over the noncancelable term of the cloud computing arrangements plus any optional renewal periods (1) that are reasonably certain to be exercised by the Company or (2) for which exercises of the renewal option is controlled by the cloud service provider. Costs incurred during the application development stage that are directly attributable to developing or obtaining software for internal use are defined as implementation costs and capitalized. Costs incurred during operation and post-implementation stages are charged to expense.

Research and Development Expenses

Research and development expenses include personnel and facility-related expenses, outside contracted services including clinical trial costs, manufacturing and process development costs, research costs and other consulting services. Research and development costs are expensed as incurred. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and amortized over the period that the goods are delivered, or the related services are performed, subject to an assessment of recoverability.

Clinical development costs are a significant component of research and development expenses. The Company has a history of contracting with third parties that perform various clinical trial activities on its behalf in connection with the ongoing development of its 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 the percentage of work completed over the life of the individual trial in accordance with agreements established with contract research organizations and clinical trial sites. The Company determines its estimates through discussions with internal clinical personnel and outside service providers as to the progress or stage of completion of trials or services and the agreed upon fee to be paid for such services.

General and Administrative Expenses

General and administrative expenses consist primarily of salaries and other related costs, including stock-based compensation, for personnel in executive, finance, accounting, legal, investor relations, facilities, business development, marketing, commercial and human resources functions. Other significant costs include facility costs not otherwise included in research and development expenses, sublicense royalty expenses, legal fees relating to corporate matters, insurance, public company expenses relating to maintaining compliance with Nasdaq listing rules and Securities and Exchange Commission (“SEC”) requirements, investor relations costs, and fees for accounting and consulting services. General and administrative costs are expensed as incurred, and the Company accrues for services provided by third parties related to the above expenses by monitoring the status of services provided and receiving estimates from its service providers and adjusting its accruals as actual costs become known.

Income Taxes

The Company accounts for income taxes using the asset and liability method whereby deferred tax assets are recognized for deductible temporary differences, and deferred tax liabilities are recognized for taxable temporary differences. Temporary differences are the differences between the reported amounts of assets and liabilities and their tax bases. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will be realized. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment.

ASC Topic 740-10-30 clarifies the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements and prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. ASC Topic 740-10-40 provides guidance on de-recognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. The Company will classify as income tax expense any interest and penalties. The Company has no material uncertain tax positions for any of the reporting periods presented.

On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) was enacted and signed into law, and GAAP requires recognition of the tax effects of new legislation during the reporting period that includes the enactment date. The CARES Act, among other things, includes changes to the tax provisions that benefits business entities and makes certain technical corrections to the 2017 Tax Cuts and Jobs Act. The tax relief measures for business entities include a five-year net operating loss (“NOL”) carrybacks, suspension of annual deduction limitation of 80% taxable income from net operating losses generated in a tax year beginning after December 31, 2017, changes in the deductibility of interest, acceleration of alternative minimum tax credit refunds, payroll tax relief, and technical correction to allow accelerated deductions for qualified improvement property. The CARES Act also provides other non-tax benefits to assist those impacted by the pandemic. The Company evaluated the impact of the CARES Act and determined the impact is immaterial.

Concentrations

The Company is subject to credit risk from its portfolio of cash equivalents and short-term investments. Under its investment policy, the Company limits amounts invested in such 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, in order of priority, are as follows: safety and preservation of principal and diversification of risk; liquidity of investments sufficient to meet cash flow requirements. The Company maintains cash, cash equivalents and short-term investment balances at three financial institutions. Management believes that the financial institutions which hold its cash are financially sound and, accordingly, minimal credit risk exists. As of December 31, 2020, and 2019, respectively, the Company’s cash balances were in excess of insured limits maintained at the financial institutions.

Recent Accounting Standards

Financial Instruments

In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses, and also issued subsequent amendments to the initial guidance, ASU 2018-19, ASU 2019-04, ASU 2019-05, ASU 2019-11, and ASU 2020-03 (collectively, Topic 326), to introduce a new impairment model for recognizing credit losses on financial instruments based on an estimate of current expected credit losses (“CECL”). Under Topic 326, an entity is required to estimate CECL on available-for-sale (“AFS”) debt securities only when the fair value is below the amortized cost of the asset and is no longer based on an impairment being “other-than-temporary”. Topic 326 also requires the impairment calculation on an individual security level and requires an entity use present value of cash flows when estimating the CECL. The credit-related losses are required to be recognized through earnings and non-credit related losses are reported in other comprehensive income. In April 2019, the FASB further clarified the scope of Topic 326 and addressed issues related to accrued interest receivable balances, recoveries, variable interest rates and prepayment. Topic 326 will be effective for public entities in fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. The new guidance requires modified retrospective application to all outstanding instruments, with a cumulative effect adjustment recorded to opening retained earnings as of the beginning of the first period in which the guidance becomes effective. The Company adopted this guidance on January 1, 2020, however, the adoption of this new guidance did not have any material impact on its consolidated financial statements.

Cloud Computing Arrangements

In August 2018, the FASB issued ASU 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (ASU 2018-15). The guidance requires a customer in a cloud computing arrangement that is a service contract to follow the internal use software guidance to determine which implementation costs to defer and recognize as an asset. It therefore requires a customer to defer potentially significant implementation costs incurred in a cloud computing arrangement that were often expensed as incurred under the legacy GAAP and recognize them as expense over the term of the hosting arrangement. ASU 2018-15 is effective for fiscal years beginning subsequent to December 15, 2019. The Company adopted this guidance on January 1, 2020. The Company recorded $1.4 million as prepaid expenses and long-term assets on the Consolidated Balance Sheet as of December 31, 2020. The Company recorded $0.2 million of amortization expense for the year ended December 31, 2020.

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.

Subsequent Events

Management of the Company evaluates events that have occurred after the balance sheet date through the date the financial statements are issued. See Note 14 - Subsequent Events.

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

12 Months Ended

Dec. 31, 2020

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

NOTE 3. CASH AND CASH EQUIVALENTS, AND SHORT-TERM INVESTMENTS

Cash equivalents, and short-term investments consist of the following (in thousands):


	December 31,		December 31,
	2020		2019

Cash equivalents - Money market funds	$	49,720	$	10,049

Cash equivalents total	$	49,720	$	10,049

Cash equivalents in the tables above exclude cash demand deposits of $17.6 million and $3.9 million as of December 31, 2020 and 2019, respectively (in thousands).


	December 31,		December 31,
Short-term investments	2020		2019
U.S. treasury securities	$	470,109	$	242,249
U.S. government agency securities		91,999		50,863
Short-term investments total	$	562,108	$	293,112

The cost and fair value of cash equivalents and short-term investments at December 31, 2020 and 2019 were as follows (in thousands):


					Gross		Gross
			Accretion		Unrealized		Unrealized
As of December 31, 2020	Cost		(Amortization)		Gains		Losses		Fair Value
U.S. treasury securities	$	471,702	$	(1,594)	$	30	$	(29)	$	470,109
U.S. government agency securities		92,248		(267)		20		(2)		91,999
Total	$	563,950	$	(1,861)	$	50	$	(31)	$	562,108


					Gross		Gross
					Unrealized		Unrealized
As of December 31, 2019	Cost		Accretion		Gains		Losses		Fair Value
U.S. treasury securities	$	241,709	$	364	$	179	$	(3)	$	242,249
U.S. government agency securities		50,712		107		44		—		50,863
Total	$	292,421	$	471	$	223	$	(3)	$	293,112

Unrealized gains and losses are included in accumulated other comprehensive loss. All short-term investments held by the Company as of December 31, 2020 and 2019 have a maturity of less than one year.

PROPERTY AND EQUIPMENT

12 Months Ended

Dec. 31, 2020

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT

NOTE 4. PROPERTY AND EQUIPMENT

Property and equipment, net consists of the following (in thousands):


	December 31,		December 31,
	2020		2019
Lab equipment	$	4,656	$	4,530
Leasehold improvements		2,573		2,372
Computer equipment		270		258
Office furniture and equipment		480		457
Construction in progress		56,758		5,417
Total Property and equipment, cost		64,737		13,034
Less: Accumulated depreciation and amortization		(5,578)		(4,498)
property and equipment, net	$	59,159	$	8,536

Depreciation expense for the years ended December 31, 2020, 2019, and 2018 was approximately $1.1 million, $1.2 million and $1.0 million, respectively.

ACCRUED EXPENSES

12 Months Ended

Dec. 31, 2020

ACCRUED EXPENSES

ACCRUED EXPENSES

NOTE 5. ACCRUED EXPENSES

Accrued expenses consist of the following (in thousands):


	December 31,		December 31,
	2020		2019

Clinical related	$	15,661	$	4,692
Accrued payroll and employee related expenses		9,032		6,866
Commercial manufacturing facility related		4,342		—
Manufacturing related		3,266		2,184
Legal and related services		1,061		866
Accrued other		1,712		1,657
	$	35,074	$	16,265

STOCKHOLDERS' EQUITY

12 Months Ended

Dec. 31, 2020

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY

NOTE 6. STOCKHOLDERS’ EQUITY

Authorized Shares of Common Stock

On June 10, 2019, the certificate of incorporation of the Company was amended to increase the number of authorized shares of the Company's common stock, par value $0.000041666, from 150,000,000 shares to 300,000,000 shares (the "Certificate of Amendment"). The Certificate of Amendment was approved by the Company's stockholders at the Company's 2019 Annual Meeting of Stockholders held on June 10, 2019.

Public Offerings

In June 2020, the Company closed an underwritten public offering of 16,935,484 shares of the Company’s common stock at a public offering price of $31.00 per share, before underwriting discounts, which included 2,540,322 shares issued upon the exercise in full by the underwriter of its option to purchase additional shares at the public offering price less the underwriting discount (the "June 2020 Public Offering"). The gross proceeds from the offering, before deducting the underwriting discounts and commissions and other offering expenses payable by the Company, were $603.7 million, with net proceeds to the Company of $567.0 million.

In October 2018, the Company completed an underwritten public offering of 25,300,000 shares of the Company’s common stock at a public offering price of $9.97 per share, before underwriting discounts, which included 3,300,000 shares issued upon the exercise in full by the underwriter of its option to purchase additional shares at the public offering price less the underwriting discount.

The gross proceeds from the offering, before deducting the underwriting discounts and commissions and other estimated offering expenses payable by the Company, were $252.2 million, with net proceeds to the Company of $236.7 million.

In January 2018, the Company closed an underwritten public offering of 15,000,000 shares of the Company’s common stock at a public offering price of $11.50 per share, before underwriting discounts, which included 1,956,521 shares issued upon the exercise in full by the underwriter of its option to purchase additional shares at the public offering price less the underwriting discount. The gross proceeds from the offering, before deducting the underwriting discounts and commissions and other offering expenses payable by the Company, were $172.5 million, with net proceeds to the Company of $162.0 million.

Preferred Stock

The Company’s certificate of incorporation authorizes the issuance of up to 50,000,000 shares of “blank check” preferred stock. At December 31, 2020, 17,000 shares were designated as 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 year ended December 31, 2020 and 2019. At December 31, 2020 and 2019, 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 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.

No Shares of Series B Convertible Preferred Stock were converted during the year ended December 31, 2020. A total of 2,273,726 shares of Series B Convertible Preferred Stock were converted into 2,273,726 shares of common stock during the year ended December 31, 2019. At December 31, 2020 and 2019, 3,581,119 shares of Series B Preferred Stock (that are convertible into 3,581,119 shares of common stock) remained outstanding, respectively.

Cancellation of Common Shares

On September 30, 2013, the Company and a third party entered into an agreement under which the Company issued 50,000 shares of unregistered stock in the Company to the third party. On January 16, 2019, the two parties entered into a confidential settlement agreement in connection with a dispute related to their prior relationship and activities. As part of the settlement, the third party returned 32,500 shares of common stock to the Company for cancellation and retained the remaining 17,500 shares. The Company included a gain of $335,000 on cancellation of 32,500 shares in Other income in its Consolidated Statement of Operations.

Warrants

There were no remaining outstanding warrants as of December 31, 2020 and 2019.

Restricted Stock Units

On June 1, 2016, the Company entered into an RSU agreement with the Company’s Chief Executive Officer, Maria Fardis, Ph.D., pursuant to which the Company granted Dr. Fardis 550,000 non-transferrable RSU at fair market value of $5.87 per share as an inducement of employment pursuant to the exception to The Nasdaq Global Market rules that generally require stockholder approval of equity incentive plans. The 550,000 RSU vest in installments as follows: (i) 137,500 RSU vested upon the first anniversary of the effective date of Dr. Fardis’ employment agreement; (ii) 275,000 RSU vest upon the satisfaction of certain clinical trial milestones; and (iii) 137,500 RSU vest in equal monthly installments over the 36-month period following the first anniversary of the effective date of Dr. Fardis’ employment, such that the RSUs were fully vested as of June 1, 2020. At December 31, 2020, the Company had no RSUs outstanding.

Stock-based compensation expense for restricted stock units are measured based on the closing fair market value of the Company's common stock on the date of grant. The stock-based compensation expenses relating to restricted stock units were $0.1 million, $0.3 million, and $0.3 million for the years ended December 31, 2020, 2019, and 2018, respectively, recorded as part of general and administrative expenses.

Equity Incentive Plans

On October 14, 2011, the Company’s Board of Directors (the “Board”) adopted the 2011 Equity Incentive Plan (the “2011 Plan”). Employees, directors, consultants and advisors of the Company are eligible to participate in the 2011 Plan. The 2011 Plan initially had 180,000 shares of common stock reserved for issuance in the form of incentive stock options, non-qualified options, common stock, and grant appreciation rights. The 2011 Plan was not approved by the Company’s stockholders within the required one-year period following its adoption and, accordingly, no incentive stock options can be granted under that plan. In August 2013, the Board and a majority of the Company’s stockholders approved an amendment to increase the number of shares available under the 2011 Plan from 180,000 shares to 1,700,000 shares, and an amendment to increase the number options or other awards that can be granted to any one person during a twelve (12) month period from 50,000 shares to 300,000 shares. The foregoing amendment to the 2011 Plan became effective in September 2013. On August 20, 2014, the Board amended the 2011 Plan to increase the number of shares available for issuance upon the exercise of stock options under the 2011 Plan from 1,700,000 to 1,900,000 shares, effective immediately. At December 31, 2020, 11,240 shares were available for future grant under the 2011 Plan.

On September 19, 2014, the Board adopted the Iovance Biotherapeutics, Inc. 2014 Equity Incentive Plan (the “2014 Plan”). The 2014 Plan was approved by the Company’s stockholders at the Company’s 2014 Annual Meeting of Stockholders held in November 2014. The 2014 Plan, as approved by the stockholders, authorized the issuance up to an aggregate of 2,350,000 shares of the Company’s common stock. On April 10, 2015, the Board amended the 2014 Plan to increase the total number of shares that can be issued under the 2014 Plan to 4,000,000 shares of the Company’s common stock. The increase in shares available for issuance under the 2014 Plan was approved by the Company’s stockholders at the Company’s 2015 Annual Meeting of Stockholders in June 2015.

On August 16, 2016, the Company’s stockholders approved an increase in the total number of shares that can be issued under the 2014 Plan to 9,000,000 shares of the Company’s common stock. At December 31, 2020, 61,575 shares were available for grant under the Company’s 2014 Plan.

On April 22, 2018, the Board adopted the Iovance Biotherapeutics, Inc. 2018 Equity Incentive Plan (the “2018 Plan”). The 2018 Plan was approved by the Company’s stockholders at the annual meeting of stockholders held in June 2018. The 2018 Plan as

approved by the stockholders authorized the issuance up to an aggregate of 6,000,000 shares of common stock reserved for issuance 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. At December 31, 2020, 7,455,537 shares of common stock were available for grant under the Company’s 2018 Plan.

Stock Options

A summary of the status of stock options at December 31, 2020, and the changes during the three years then ended, 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 January 1, 2018	6,072,368	$	7.42
Issued	2,960,620		14.73
Exercised	(1,336,514)		7.45
Expired/Cancelled	(807,187)		10.04
Outstanding at December 31, 2018	6,889,287	$	10.25
Issued	4,166,600		14.73
Exercised	(727,492)		8.85
Expired/Cancelled	(833,683)		13.87
Outstanding at December 31, 2019	9,494,712	$	12.00
Issued	4,981,001		28.17
Exercised	(973,854)		9.92
Expired/Cancelled	(886,221)		18.67
Outstanding at December 31, 2020	12,615,638	$	18.08	7.81	$	358,726

Options exercisable at December 31, 2020	6,401,443	$	11.70	6.67	$	222,631

A summary of outstanding and exercisable stock options as of December 31, 2020 is as follows:


	Options Outstanding				Options Exercisable
		Weighted				Weighted
		Average	Weighted			Average	Weighted
		Remaining	Average			Remaining	Average
Range of Exercise	Number of	Contractual	Exercise Price		Number of	Contractual	Exercise Price
Prices	Shares	Life	Per Share		Shares	Life	Per Share
$ 5.05-$ 7.3	1,307,133	5.26	$	5.98	1,307,133	5.26	$	5.98
$ 7.4-$ 8.17	1,309,536	5.70		7.67	1,300,911	5.68		7.67
$ 8.3-$ 11.05	1,072,016	6.92		9.60	808,228	6.55		9.54
$ 11.15-$ 11.26	1,377,597	7.93		11.26	812,887	7.76		11.26
$ 11.44-$ 16.8	1,481,860	7.33		15.57	1,282,900	7.30		15.71
$ 16.94-$ 22.9	1,291,100	8.54		19.73	674,672	8.33		19.59
$ 23-$ 23.87	256,300	9.08		23.59	12,375	8.90		23.17
$ 23.88-$ 23.88	1,369,946	9.05		23.88	—	—		—
$ 23.93-$ 25.78	1,406,500	8.97		25.32	76,787	8.56		25.65
$ 27.5-$ 117	1,743,650	9.54		35.25	125,550	8.77		36.54
	12,615,638	7.81	$	18.08	6,401,443	6.67	$	11.70

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 our 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 year ended December 31, 2020 was $0.06 million. As of December 31, 2020, no shares were issued under the 2020 ESPP and there was $0.5 million of unrecognized compensation cost associated with the 2020 ESPP, which will be recognized over 6 months.

Stock-Based Compensation

Total stock-based compensation expense related to all of the Company’s stock-based awards was recorded on the Consolidated Statements of Operations as follows (in thousands):



	Years Ended December 31,
	2020		2019		2018
Research and development	$	19,727	$	11,396	$	9,305
General and administrative		21,160		12,881		10,722
Total stock-based compensation expenses	$	40,887	$	24,277	$	20,027

Total stock-based compensation broken down based on each individual instrument was as follows (in thousands):



	Years Ended December 31,
	2020		2019		2018
Stock option expenses	$	40,714	$	23,964	$	19,758
Restricted stock unit expenses		112		313		269
2020 ESPP expenses		61		—		—
Total stock-based compensation expenses	$	40,887	$	24,277	$	20,027

As of December 31, 2020, there was $75.9 million of total unrecognized compensation expenses related to non-vested employee options to be recognized over a weighted average period of 1.90 years.

The weighted average grant date fair value for employee options granted under the Company's stock option plans during the years ended December 31, 2020, 2019, and 2018 was $17.32, $9.48, and $14.44 per option respectively.

The aggregate intrinsic value in the table above reflects the total pre-tax intrinsic value (the difference between the Company’s closing stock price on the last trading day of the year ended December 31, 2020 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 December 31, 2020. The intrinsic value of the Company’s stock options changes based on the closing price of the Company’s common stock.

The total pre-tax intrinsic value of stock options exercised during the year ended December 31, 2020, 2019, and 2018 were $21.4 million, $5.3 million, and $2.3 million, respectively.

The following table summarizes the assumptions relating to options granted pursuant to the Company’s equity incentive plans for the years ended December 31, 2020, 2019, and 2018:


	Stock Option			ESPP
	Years Ended December 31,
Assumptions:	2020	2019	2018	2020
Expected term (years)	5.18 - 6.19	6.14 - 6.06	6.50 - 5.13	0.50
Expected volatility	69.99% - 70.99%	71.62% - 70.63%	200.28% - 167.54%	54.90%
Risk-free interest rate	0.28% - 1.83%	2.59% - 1.62%	2.97% - 2.27%	0.09%
Expected dividend yield	0%	0%	0%	0%

Expected Dividend Yield —The Company has never paid dividends and does not expect to pay dividends in the foreseeable future.

Risk-Free Interest Rate —The risk-free interest rate was based on the market yield currently available on United States Treasury securities with maturities approximately equal to the option’s expected term.

Expected Term —The expected term of the stock option grants was calculated based on historical exercises, cancellations, and forfeitures of stock options and outstanding option shares

Expected Volatility —The expected volatility is based on the historical volatility for the Company's stock over a period equal to the expected terms of the options.

Forfeiture Rate —The Company recognizes forfeitures as they occur.

Each of the inputs discussed above is subjective and generally requires significant management judgment.

EMPLOYEE BENEFIT PLAN

12 Months Ended

Dec. 31, 2020

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN

NOTE 7. EMPLOYEE BENEFIT PLAN

The Company maintains a defined contribution plan covering substantially all U.S. employees under Section 401(k) of the Internal Revenue Code of 1986, as amended (the “IRC”). The Company's matching contribution to the plan was $1.2 million, $0.9 million, and $0.5 million for the years ended December 31, 2020, 2019, and 2018, respectively.

INCOME TAXES

12 Months Ended

Dec. 31, 2020

INCOME TAXES

INCOME TAXES

NOTE 8. INCOME TAXES

Net deferred tax assets (liabilities) are summarized as follows (in thousands):


	As of December 31,
	2020		2019
Deferred income tax asset:
Net operating loss carry forward	$	144,087	$	95,473
Stock-based compensation		11,364		8,851
Tax credit carry forwards		32,508		22,711
Lease liabilities		11,051		2,529
Depreciation and amortization		250		98
Reserves and accruals		1,866		1,410
Deferred tax assets before valuation allowance		201,126		131,072
Less: valuation allowance		(189,412)		(128,720)
Net deferred income tax assets		11,714		2,352
Deferred tax liabilities:
Depreciation and amortization		(11,714)		(2,352)
Net deferred tax assets (liabilities)	$	—	$	—

Reconciliation of the effective income tax rate to the U.S. statutory rate is as follows:


	Years ended December 31,
	2020		2019		2018
Federal statutory tax rate	(21)	%	(21)	%	(21)	%
Orphan Drug & Research credits	(3)		(4)		(3)
Permanent and other differences	1		1		1
Tax rate change	—		—		—
State tax, net of federal benefit	—		(2)		(1)
	(23)	%	(26)	%	(24)	%
Valuation allowance	23	%	26	%	24	%
Effective tax rate	—	%	—	%	—	%

The components of income tax expense (benefit) are as follows (in thousands):


	Years Ended December 31,
	2020		2019		2018
Federal:
Current	$	—	$	—	$	—
Deferred		(59,931)		(47,010)		(28,277)
State and Local
Current		—		—		—
Deferred		(760)		(3,564)		(2,020)
Change in Valuation Allowance		60,691		50,574		30,297
Total income tax expense (benefit)	$	—	$	—	$	—

The Company had net operating loss carryovers (“NOLs”) for federal and state income tax purposes of approximately $662.4 million and $128.9 million, respectively, as of December 31, 2020. $142.4 million of federal NOLs will expire beginning in 2027, while $520.0 million generated after Tax Reform will have an indefinite life. The state NOLs will expire if unused in years 2030 through 2038.

The Company’s utilization of NOLs is subject to an annual limitation due to ownership changes that have occurred previously or that could occur in the future as provided in Section 382 of the Code (“Section 382”), as well as similar state provisions. Section 382 limits the utilization of NOLs when there is a greater than 50% change of ownership as determined under the regulations. Since its formation, the Company has raised capital through the issuance of capital stock and various convertible instruments which, combined with the purchasing shareholders’ subsequent disposition of these shares, has resulted in an ownership change as defined by Section 382, and could result in an ownership change in the future upon subsequent disposition. The Company’s utilization of NOLs may also be adversely affected by future changes in federal and state tax laws and regulations.

In assessing the realization of deferred tax assets, management considers whether it is more likely than not that some portion or all the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon future generation for taxable income during the periods in which temporary differences representing net future deductible amounts become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. After consideration of all the information available, management believes that significant uncertainty exists with respect to future realization of the deferred tax assets and has therefore established a full valuation allowance. For the years ended December 31, 2020, 2019, and 2018, the change in the valuation allowance was approximately $60.7 million, $50.6 million, and $30.3 million respectively.

The Company evaluated the provisions of ASC 740 related to the accounting for uncertainty in income taxes recognized in an enterprise’s financial statements. ASC 740 prescribes a comprehensive model for how a company should recognize, present, and disclose uncertain positions that the Company has taken or expects to take in its tax return. For those benefits to be recognized, a tax position must be more-likely-than-not to be sustained upon examination by taxing authorities. Differences between tax positions taken or expected to be taken in a tax return and the net benefit recognized and measured pursuant to the interpretation are referred to as “unrecognized benefits.” A liability is recognized (or amount of net operating loss carry forward or amount of tax refundable is

reduced) for unrecognized tax benefit because it represents an enterprise’s potential future obligation to the taxing authority for a tax position that was not recognized as a result of applying the provisions of ASC 740.

If applicable, interest costs related to the unrecognized tax benefits are required to be calculated and would be classified as income tax expenses in the Consolidated Statement of Operations. Penalties would be recognized as a component of “General and Administrative Expenses” in the Consolidated Statement of Operations.

A reconciliation of the beginning and ending balances of the unrecognized tax benefits during the years ended December 31, 2020, 2019, and 2018 is as follows (in thousands):


	Years Ended December 31,
	2020		2019		2018
Unrecognized benefit - beginning of period	$	10,038	$	6,344	$	4,111
Gross decreases - prior period tax positions		—		—		118
Gross increase current period tax positions		4,394		3,694		2,115
Unrecognized benefit - end of period	$	14,432	$	10,038	$	6,344

No interest or penalties on unpaid tax were recorded during the years ended December 31, 2020, 2019, and 2018, respectively. The Company does not anticipate any significant changes within 12 months of this reporting date of its uncertain tax positions.

The Company files tax returns in the U.S. federal and state jurisdictions. The U.S. federal and U.S. state taxing authorities may choose to audit tax returns for tax years beyond the statute of limitation period due to significant tax attribute carryforwards from prior years, making adjustments only to carryforward attributes. The Company is not currently under examination by income tax authorities in federal, state or other foreign jurisdictions.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

LICENSES AND AGREEMENTS

12 Months Ended

Dec. 31, 2020

LICENSES AND AGREEMENTS

LICENSES AND AGREEMENTS

NOTE 9. LICENSES AND AGREEMENTS

National Institutes of Health (NIH) and the National Cancer Institute (NCI)

Cooperative Research and Development Agreement (CRADA)

In August 2011, the Company signed a five-year CRADA with the NCI to work with Dr. Steven Rosenberg on developing adoptive cell immunotherapies that are designed to destroy metastatic melanoma cells using a patient’s tumor infiltrating lymphocytes.

In January 2015, the Company executed an amendment to the CRADA to include four new indications. As amended, in addition to metastatic melanoma, the CRADA included the development of TIL therapy for the treatment of patients with bladder, lung, triple-negative breast, and Human Papilloma Virus (“HPV”)-associated cancers.

In August 2016, the NCI and the Company entered a second amendment to the CRADA. The principal changes effected by the second amendment included (i) extending the term of the CRADA by another five years to August 2021, and (ii) modifying the focus on the development of unmodified TIL as a stand-alone therapy or in combination with U.S. Food and Drug Administration (“FDA”) - licensed products and commercially available reagents routinely used for adoptive cell therapy. The parties will continue 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.

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 cGMP conditions, suitable for use in clinical trials, where the Company holds the investigational new drug application for such clinical trial. The extended CRADA has a five-year term expiring in August 2021. 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 $2.0 million, $2.2 million, and $2.0 million for the years ended December 31, 2020, 2019 and 2018, respectively, as research and development expenses.

Patent License Agreement Related to the Development and Manufacture of TIL

Effective October 5, 2011, 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 (NIH), which was subsequently amended on February 9, 2015 and October 2, 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. The Patent License Agreement requires the Company to pay royalties based on a percentage of net sales (which percentage is in the mid-single digits), a percentage of revenues from sublicensing arrangements, and lump sum benchmark royalty payments on the achievement of certain clinical and regulatory milestones for each of the various indications and other direct costs incurred by the NIH pursuant to the agreement. The Company anticipates making a milestone payment in conjunction with the submission of a Biologics License Application for any of its product candidates covered by the Patent License Agreement.

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 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 December 2016, the Company entered into a new three-year Sponsored Research Agreement with H. Lee Moffitt Cancer Center (“Moffitt”) which expired in December 2019. In June 2020, the Company entered into a new Sponsored Research Agreement with 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. At the same time, 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. In the years ended December 31, 2020, 2019 and 2018, the Company recorded research and development costs of $0.6 million, $0.7 million, and $1.2 million, 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. 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 year ended December 31, 2020, 2019, and 2018.

The Company entered into a 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 $0.1 million for the years ended December 31, 2020, 2019 and 2018 as research and development expenses in connection with this agreement.

M.D. Anderson Cancer Center

Strategic Alliance Agreement

On April 17, 2017, the Company entered into a Strategic Alliance Agreement (the “SAA”) with 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. In return, the Company acquired all rights to inventions resulting from the studies and has been granted a non-exclusive, sub-licensable, royalty-free, and perpetual license to specified background intellectual property of MDACC reasonably necessary to exploit, including the commercialization thereof. The Company has also been granted certain rights in clinical data generated by MDACC outside of the clinical trials to be performed under the SAA. The SAA’s term shall continue in effect until the later of the fourth anniversary of the SAA or the completion or termination of the research and receipt by the Company of all deliverables due from MDACC thereunder. In May 2017, the Company made a prepayment of $1.4 million followed by subsequent payment of $2.5 million under this agreement. The Company recorded $1.1 million, $3.4 million and $0.8 million associated with the SAA for the year ended December 31, 2020, 2019, and 2018 as research and development expenses, respectively.

WuXi

In November 2016, the Company entered into a three-year manufacturing and services agreement (“MSA”) with WuXi AppTec, Inc. (“WuXi”) pursuant to which WuXi agreed to provide manufacturing and other services, which has since been amended and assigned to our subsidiary Iovance Biotherapeutics Manufacturing LLC. Under the agreement, 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 statements of work for the first suite were amended in 2019 and September 2020, and the second suite was amended in 2019. The statements of work for facility include a fixed component to reserve a dedicated suite and a trained work force, and a variable component, mainly materials and testing used during the manufacturing processes. Both statements of work provide for adjustments to the targeted production capacity levels and the corresponding fixed quarterly fees upon written notice from the Company of 30 days and 90 days for the first and second dedicated suites, respectively. The terms of the related statements of work for the first and second dedicated manufacturing suites currently extend to August 2022 and June 2021, respectively. The Company recorded costs associated with agreements with WuXi of $20.6 million, $28.4 million, and $15.1 million for the years ended December 31, 2020, 2019, and 2018 respectively, as research and development expenses.

Cellectis

On January 12, 2020, 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, in order 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 from Cellectis of $0.4 million the year ended December 31, 2020, respectively.

Novartis

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 for the year ended December 31, 2020.

LEASES

12 Months Ended

Dec. 31, 2020

LEASES

LEASES

NOTE 10. LEASES

Facilities Leases

The Company has evaluated the following existing facility leases and determined that, effective upon the adoption of Topic 842, they were all operating leases. Operating lease right-of-use assets and liabilities were recognized as of January 1, 2019 based on the present value of the remaining lease payments over the lease term. As the Company's leases do not provide an implicit rate, the Company utilized a third party in determining an incremental borrowing rate based on the information available as of the adoption date of Topic 842 to obtain the present value of lease payments. The Company's lease terms may include options to extend or terminate the lease which are included in the lease term when it is reasonably certain that it will exercise any such options. Lease expense is recognized on a straight-line basis over the expected lease term. The Company elected not to apply the recognition requirements of Topic 842 for short-term leases that have a lease term of 12 months or less.

Tampa Lease

In December 2014, the Company commenced a five-year non-cancellable operating lease with the University of South Florida Research Foundation for a 5,115 square foot facility located in Tampa, Florida. The facility is part of the University of South Florida research park and is used as the Company’s research and development facilities. The Company had the option to extend the lease term of this facility for an additional five-year period on the same terms and conditions, except that the base rent for the renewal term will be increased in accordance with the applicable consumer price index.

In April 2015, the Company amended the original lease agreement to increase the rentable space to 6,043 square feet. In September 2016, the Company further increased the rentable space to 8,673 square feet. The per square foot cost and term of the lease were unchanged, and rent payments are approximately $20,000 per month. In December 2019, the Company entered into an agreement to extend the lease term to December 18, 2024 for approximately $20,500 a month.

In June 2020, the Company amended the lease agreement to further increase the rentable space to 13,139 square feet and extend the lease term to June 5, 2025 for approximately $34,500 a month.

San Carlos Lease

On August 4, 2016, the Company entered into an agreement to lease 8,733 square feet in San Carlos, California. The term of the lease is 54 months subsequent to the commencement date and will expire in April 2021. Monthly lease payments are approximately $38,000.

On April 28, 2017, the Company entered into a sublease agreement with Teradata US, Inc., pursuant to which the Company agreed to sublease certain office space located adjacent to the Company's headquarters for approximately $26,000 per month. The space consists of approximately 11,449 rentable square feet in the building located in San Carlos, California. The sublease for this space expired on October 31, 2018. Monthly lease payments were approximately $26,000.

On October 19, 2018, the Company entered into an agreement to lease 12,322 square feet of office space located adjacent to the Company's headquarters in San Carlos, California. This lease replaces the sublease of 11,449 square feet of office space in the same

facility that expired on October 31, 2018. The term of the lease is 30 months subsequent to the commencement date, November 1, 2018, and will expire in April 2021. Monthly lease payments are approximately $59,000, subject to an annual increase of 3%.

On June 19, 2019, the Company entered into a first amendment (the “Amended Lease”) to its previously disclosed lease agreement with Hudson Skyway Landing, LLC (the “Lease”) for additional space at its corporate headquarters in San Carlos, California. Under the Amended Lease, the Company will lease an additional 8,110 square feet (the “Expansion Space”), for a total of approximately 20,432 square feet of space on the first floor of the building located at 999 Skyway Road, San Carlos, California, commonly known as Skyway Landing II. The term of the Amended Lease remains the same as that of the Lease and expires on April 30, 2021, unless earlier terminated in accordance with the Amended Lease. The Company's monthly base rent for the Expansion Space under the Amended Lease will be approximately $39,000 for the first year, and $40,000 for the second year.

New York Lease

The Company leased office space in New York for a monthly rental of approximately $18,000 a month from January 2017 through July 2017. On June 5, 2017, the Company entered into an agreement whereby the Company will lease office space from August 1, 2017 to July 31, 2018, for approximately $9,000 a month. On April 20, 2018, the Company entered into an agreement to extend the lease term to January 31, 2019 for approximately $7,000 a month. On November 2, 2018, the Company entered into an agreement to extend the lease term to July 31, 2019 for approximately $4,000 a month. On May 1, 2019, the Company entered into an agreement to extend the lease term to January 31, 2020 for approximately $4,000 a month. On October 24, 2019, the Company entered into an agreement to extend the lease term to April 30, 2020 for approximately $4,000 a month. On January 23, 2020, the Company entered into an agreement to extend the lease term to July 31, 2020 for approximately $4,000 a month. On May 24, 2020, the Company entered into an agreement to extend the lease term to October 31, 2020 for approximately $4,000 a month. On September 1, 2020, the Company entered into an agreement to extend the lease term to January 31, 2021, for approximately $4,000 a month. On January 31, 2021, the lease terminated, and we closed our New York office.

Philadelphia Office Lease

On May 2, 2019, the Company entered into an agreement to lease approximately 1,500 square feet of office space in Philadelphia, Pennsylvania until July 1, 2019 for a rate of $2,000 a month, and then approximately 4,500 square feet of office space for the remainder of a three-year term at an initial rate of $11,063 per month, subject to annual increases of 2.5%.

On August 1, 2020, the Company entered into an agreement to lease approximately 2,965 square feet of a training facility space in Philadelphia, Pennsylvania for a twelve-month term at a rate of approximately $6,500 per month.

Commercial Manufacturing Facility Agreement

On May 28, 2019, the Company entered into a lease agreement with 300 Rouse Boulevard, LLC (the “Commercial Manufacturing Facility Lease”) for a build-to-suit commercial manufacturing facility, laboratories, and offices located in Philadelphia, Pennsylvania. Under the Commercial Manufacturing Facility Lease, the Company leases approximately 136,000 rentable square feet of space in a building located at 300 Rouse Boulevard, Philadelphia, Pennsylvania (the “Premises”). The construction of the commercial manufacturing facility began in July 2019 and has been substantially completed.

The Company determined the commencement date of the Commercial Manufacturing Lease to be October 7, 2020 in accordance with Topic 842 when its landlord made the Premise available for the Company’s use and the Company obtained control over the use of the Premises. The Commercial Manufacturing Facility Lease includes an option to extend the term of the lease, exercisable under certain conditions as described in the Commercial Manufacturing Facility Lease, such that the overall term, when added to the initial term, shall be 359 months, by giving the landlord prior written notice thereof at least 18 months in advance of the expiration date. In determining the lease term, the Company did not include the periods covered by the option to extend the lease as it determined that it is not reasonably certain that the Company will exercise such option. Upon the commencement date, the Company recognized operating lease liabilities and right-of-use assets of $41.3 million and $45.7 million, respectively.

The Company’s monthly base rent under the Lease will be approximately $320,000, subject to an annual increase of 2% for the first ten years, and an annual increase of the greater of 2% or 75% of the average ten-year consumer price index. The Company is also responsible for paying operating expenses, which are expected to be approximately $72,000 per month in 2021.

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. In conjunction with the adoption of Topic 842 on January 1, 2019, the Company reevaluated all of its material contracts it has, to determine whether they contain a lease under Topic 840. An arrangement is considered a lease or contains a lease if an underlying asset is explicitly or implicitly identified and use of the asset is controlled by the customer. Based on this evaluation, the Company concluded that all of its contracts with CMOs contained embedded operating leases because the suites used for its production are implicitly identified, is only used by the Company exclusively 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.

The guidance 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 used 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 Company leases certain furniture and equipment that has a lease term of 12 months or less. Since the commencement date does 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.

The balance sheet classification of the Company’s right-of-use asset and lease liabilities was as follows:


	December 31, 2020		December 31, 2019
Operating lease right-of-use assets	$	54,756	$	10,695
Operating lease liabilities
Current portion included in current liabilities		6,284		7,252
long-term portion included in non-current liabilities		45,375		4,248
Total Operating lease liabilities	$	51,659	$	11,500

The following table summarizes components of lease expenses, which were included in Total expenses in the Company’s Consolidated Statement of Operations, and other information related to our operating leases as follows (in thousands except weighted-average remaining lease terms and discount rates):


	For the Year			For the Year
	Ended			Ended
	December 31, 2020			December 31, 2019

Operating lease cost		8,728		$	9,213
Variable lease cost		5,585			5,801
Short-term lease cost		91			72
Total lease cost		14,404		$	15,086

Other information

Cash paid for amounts included in the measurement of lease liabilities included in Operating cashflows	$	8,372		$	8,622
Increase in right-of-use assets from the adoption of Topic 842	$	—		$	10,380
Right-of-use assets obtained from entering new leases	$	50,327		$	4,092
Increase in right-of-use assets from lease modifications	$	1,306		$	3,660
Weighted-average remaining lease terms (years)		16.76			1.74
Weighted-average discount rates		8.3	%		7.7	%

Variable lease cost is determined based on performance or usage in accordance with the contractual agreements, and not based on an index or rate.

As of December 31, 2020, the maturities of the Company's operating lease liabilities were as follows (in thousands):


			CMO
	Facility		embedded
	leases		leases		Total
2021	$	3,912	$	6,288	$	10,200
2022		4,281		1,782		6,063
2023		4,286		—		4,286
2024		4,375		—		4,375
2025		4,281		—		4,281
Thereafter		74,206		—		74,206
Total lease payments	$	95,341	$	8,070	$	103,411
Less: Present value adjustment		(51,474)		(278)		(51,752)
Operating lease liabilities	$	43,867	$	7,792	$	51,659

Operating lease liabilities are based on the net present value of the remaining lease payments over the remaining lease term. In determining the present value of lease payments, the Company used its incremental borrowing rate based on the information available at the date of adoption of Topic 842 or the date of lease modifications. As of December 31, 2020, the weighted average remaining lease term is 16.76 years and the weighted average discount rate used to determine the operating lease liabilities was 8.3%.

LEGAL PROCEEDINGS

12 Months Ended

Dec. 31, 2020

LEGAL PROCEEDINGS

LEGAL PROCEEDINGS

NOTE 11. LEGAL PROCEEDINGS

Derivative Lawsuit. On December 11, 2020, a purported stockholder derivative complaint was filed by plaintiff Leo Shumacher against the Company, as nominal defendant, and 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 and seeks unspecified damages on behalf 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. On April 8, 2016, a lawsuit (“the First Solomon Suit”) titled Solomon Capital, LLC, Solomon Capital 401(K) Trust, Solomon Sharbat and Shelhav Raff v. Lion Biotechnologies, Inc. was filed by Solomon Capital, LLC, Solomon Capital 401(k) Trust, Solomon Sharbat and Shelhav Raff (“Solomon Plaintiffs”) against the Company in the Supreme Court of the State of 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 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 July 31, 2020, the Solomon Plaintiffs, through new counsel, filed a motion for reconsideration of the dismissal of the First Solomon Suit for want of prosecution. On August 11, 2020, the Company filed an opposition brief against the Solomon Plaintiffs’ motion for reconsideration. On August 17, 2020, the Solomon Plaintiffs filed a reply brief in support of their motion for reconsideration. On September 2, 2020, the Solomon Plaintiffs filed a notice of appeal of the dismissal 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 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 in the Supreme Court of the State of New York, County of New York (index no. 655668/2019). In the Second Solomon Suit, the Solomon Plaintiffs allege that they are third party beneficiaries of a “finder’s fee agreement” that prior management entered into with a third party unlicensed entity in 2012 in connection with seeking financing, that an agreement or understanding existed between the Company and the plaintiffs that the plaintiffs would be paid fees and commissions (in cash and stock) if they obtained financing for the Company, and that they directly and indirectly introduced investors to the Company who invested in the Company, or were willing to invest in the Company. Finally, the Solomon Plaintiffs allege that they were promised a license to use the Company’s technology in Israel. The plaintiffs claim that the Company breached the foregoing understandings, promises and agreements and, as a result, they are entitled to certain damages. The Solomon Plaintiffs also allege that Manish Singh, the Company’s former Chief Executive Officer, committed fraud and took shares belonging to them. On February 18, 2020, the Company filed a removal petition and removed the Second Solomon Suit to the U.S. District Court for the Southern District of New York, where the case has been assigned case no. 1:20-cv-1391. The Company has not yet responded to the complaint in the Second Solomon Suit. On May 22, 2020, the Company moved to dismiss the Second Solomon Suit for lack of personal jurisdiction. On July 17, 2020, the Solomon Plaintiffs filed an opposition brief against the Company’s motion to dismiss for lack of personal jurisdiction. On August 7, 2020, the Company filed a reply brief in support of the Company’s motion to dismiss for lack of personal jurisdiction.

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.

Litigation Involving Dr. Steven Fischkoff. On June 13, 2017, in an action titled Steven Fischkoff v. Lion Biotechnologies, Inc. and Maria Fardis, Dr. Steven Fischkoff, the Company’s former Vice President and Chief Medical Officer, filed a lawsuit against the Company in the Supreme Court of the State of New York, County of New York. Dr. Fischkoff was dismissed by the Company on March 28, 2017. Dr. Fischkoff was terminated “for cause” as that term is defined in his employment agreement. In his complaint, Dr. Fischkoff alleges breaches of his employment agreement and violation of New York Labor Law for failure to pay monies purportedly

owed to him, and seeks to recover amounts including severance pay and retention bonus (totaling $300,000), a prorated incentive bonus, and amounts relating to unvested options to 150,000 shares of the Company's common stock, together with prejudgment interest, costs, expenses and attorneys’ fees. On July 5, 2017, the Company filed a removal petition and removed the lawsuit to the U.S. District Court for the Southern District of New York, where the case has been assigned case no. 1:17-cv-05041. On July 14, 2017, the Company filed a partial answer and counterclaims against Dr. Fischkoff, denying his allegations, and alleging breach of contract and related claims, breach of fiduciary duty, and state and federal trade secret misappropriation and related claims, and sought a temporary restraining order and preliminary injunction against Dr. Fischkoff. On July 18, 2017, the court issued a temporary restraining order against Dr. Fischkoff requiring him to return the Company's materials, prohibiting him from disclosing or using the Company’s materials, and granting expedited discovery. On June 25, 2018, pursuant to a stipulation between the parties, the court entered a permanent injunction prohibiting Dr. Fischkoff from disclosing, possessing, or using any of the Company’s proprietary materials or trade secrets. On July 5, 2018, the court entered an order dismissing two of Dr. Fischkoff’s claims against the Company and Dr. Fardis. On October 18, 2018, Dr. Fischkoff amended his complaint to assert a new claim for defamation arising from SEC filings in which the Company provided the information about this litigation. On September 23, 2020, the parties reached a confidential settlement in this matter, and on October 13, 2020, the court approved a stipulation of dismissal with prejudice filed by the parties.

Other Matters. In connection with the Company’s reincorporation from Nevada to Delaware in 2017, the Company (as a Delaware corporation) untimely filed a post-effective amendment to adopt a Form S-8 registration statement that the Company filed (as a Nevada corporation) to register the shares underlying the Company’s 2011 Equity Incentive Plan. Before the Company filed the required post-effective amendment, options to purchase 200,000 shares were exercised under the 2011 Equity Incentive Plan. The effect of the delayed post-effective amendment filing on the 200,000 option shares is uncertain, but the issuance and sale of the shares may not have been in compliance with the Form S-8 registration statement. The existence of any liability to the Company, and the amount of any such liability to the Company, as a result of the issuance of the 200,000 shares is uncertain. Accordingly, no accrual for a potential claim has been made by the Company in its consolidated financial statements.

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.

QUARTERLY UNAUDITED RESULTS

12 Months Ended

Dec. 31, 2020

QUARTERLY UNAUDITED RESULTS

QUARTERLY UNAUDITED RESULTS

NOTE 12. QUARTERLY UNAUDITED RESULTS

The results of operations by quarter for the years ended December 31, 2020 and 2019 are as follows:


	2020									2019
	(in thousands, except per share information)
	Q1		Q2		Q3		Q4			Q1	Q2		Q3		Q4
Revenue	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Net loss	$	(69,595)	$	(63,018)	$	(58,571)	$	(68,397)	$	(36,950)	$	(47,551)	$	(49,487)	$	(63,568)
Net loss per share, basic and diluted	$	(0.55)	$	(0.47)	$	(0.40)	$	(0.47)	$	(0.30)	$	(0.38)	$	(0.40)	$	(0.50)
Weighted average share used in computing net loss per share, basic and diluted		126,568		133,162		146,492		146,738		123,415		123,567		124,035		126,273

RELATED PARTY TRANSACTIONS

12 Months Ended

Dec. 31, 2020

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS

NOTE 13. RELATED PARTY TRANSACTIONS

On September 14, 2017, the Company entered into a three-year consulting agreement with Iain Dukes, D. Phil, the Chairman of the Board. As compensation for his consulting services, the Company granted Dr. Dukes a stock option to purchase up to 150,000 shares of the Company’s common stock, at an exercise price of $7.30 per share. Under the consulting agreement, Dr. Dukes agreed to provide the Company with services regarding business development opportunities, licensing transactions and technology acquisitions by the Company, and any such strategic initiatives appropriate for the Company that Dr. Dukes may identify. The granted stock options vest in 12 quarterly installments (with 1/12th of the option shares having vested on the date of grant). The vesting of the granted stock options will accelerate, and the entire award will become fully vested upon the closing of a significant licensing transaction, a material product acquisition, a material strategic transaction, or upon a change of control transaction. The

Company recognized $0.2 million, $0.4 million and $0.7 million in stock-based compensation expense related to this consulting agreement during the years ended December 31, 2020, 2019 and 2018, respectively.

SUBSEQUENT EVENT

12 Months Ended

Dec. 31, 2020

SUBSEQUENT EVENT

SUBSEQUENT EVENTS

NOTE 14. SUBSEQUENT EVENTS

New Headquarters Lease

On February 3, 2021, the Company entered into a lease agreement with ARE-San Francisco No. 63, LLC (the “New Headquarters Lease”) for laboratories and offices to be constructed in Suite 400 of an existing building located at 825 Industrial Road, San Carlos, California (the “Building”), commonly known as The District. Under the New Headquarters Lease, the Company will lease approximately 49,918 rentable square feet of space in the Building (the “Premises”). The New Headquarters Lease is for a term of 120 months, commencing upon the first day of the first full month (the “Rent Commencement Date”) after the earlier to occur of (i) the date that is 12 months and one day after the execution date (the “Commencement Date”), which is January 30, 2022, or (ii) the date that the Tenant Improvements are substantially completed; provided, however, that the Rent Commencement Date shall be delayed 1 day for each day after the Commencement Date that (a) to the extent that, after the Commencement Date, any governmental authority having jurisdiction, as a result of the COVID-19 outbreak in the U.S., declares or implements any order or mandate that restricts construction activities in San Mateo County, California (any such order or mandate, a “Government Mandate”), to the extent that such Government Mandate precludes the construction of tenant improvements, or (b) a landlord delay occurs. Construction of the Company’s offices is expected to extend through 2021. The New Headquarters Lease includes an option to extend the term of the lease for 60 months, exercisable under certain conditions and at a market rate as described in the New Headquarters Lease.

Commencing 210 days after the Rent Commencement Date as the result of a rent abatement, the Company’s monthly base rent under the New Headquarters Lease will be $279,540.80, subject to an annual increase of 3%. Beginning in 2022, the Company will also be responsible for paying operating expenses.

Extension of Existing Headquarters Leases

On February 3, 2021, the Company entered into two amendments (the “Suite 150 Second Amendment” and the “Suite 100 and Suite 125 First Amendment”) to its previously disclosed lease agreements with Hudson Skyway Landing, LLC, for space located on the first floor of the building located at 999 Skyway Road, San Carlos, California, commonly known as Skyway Landing II.

Under the Suite 100 and Suite 125 Second Amendment, the Company will extend its previously disclosed amended lease of approximately 20,432 rentable square feet of space, which would have expired on April 30, 2021, to December 31, 2021. The Company’s monthly base rent under the Suite 100 and Suite 125 Second Amendment will be $103,181.60. The Company is also responsible for paying its portion of operating expenses and real estate taxes. The Company has an option to extend the expiration of the Suite 100 and Suite 125 Second Amendment for one month or six months, at its discretion, by providing notice as specified in the Suite 100 and Suite 125 Second Amendment.

Under the Suite 150 First Amendment, the Company will extend its previously disclosed lease of approximately 8,733 rentable square feet of space, which also would have expired on April 30, 2021, to December 31, 2021. The Company’s monthly base rent under the Suite 150 First Amendment will be $44,101.65. The Company is also responsible for paying its portion of operating expenses and real estate taxes. The Company has an option to extend the expiration of the Suite 150 First Amendment for one month or six months, at its discretion, by providing notice as specified in the Suite 150 First Amendment.

Economic Stimulus Program Loan

On January 26, 2021, the Company entered into a Loan Note dated January 26, 2021 (the “Loan Note”) and accompanying Economic Stimulus Program Loan Agreement with PIDC – Local Development Corporation, a Pennsylvania nonprofit corporation (the “Lender”), pursuant to which the Lender agreed to make a loan (the “Job Creation Loan”) to the Company in a principal amount of $1.0 million. The Job Creation Loan will be for a term of five years starting on the date of the issuance of a final certificate of occupancy for the Company’s leased premises in Philadelphia, Pennsylvania. The Job Creation Loan is unsecured, bears no interest, and will be forgiven by the Lender in the amount of $2,000 per full-time or “full time equivalent” (defined as two or more part time employees whose working hours total at least 35 hours a week) employee with an average salary of at least $80,000 (“FT Employees”), up to a maximum amount equal to the amount of the Job Creation Loan, as calculated based on the average number of

FT Employees employed at the Company’s premises during the period of the 5-year term beginning on the date that is six months prior to the maturity date and ending on the maturity date. If the Job Creation Loan is not forgiven in full by the maturity date, the remaining balance of the loan not forgiven will become payable on the maturity date. The Loan Note includes customary events of default. Upon the occurrence of an event of default, the Lender will have the right to exercise remedies against the Company, including the right to require immediate payment of all amounts due under the Loan Note.

Entry Into a Material Definitive Agreement

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, par value $0.000041666 per share (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, originally filed with the Securities and Exchange Commission on May 27, 2020, which became effective immediately upon filing.

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 (the “Securities Act”). 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.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Dec. 31, 2021

Dec. 31, 2020

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Cash, Cash Equivalents, and Short-term Investments

Restricted Cash


	December 31,		December 31,		December 31,
	2020		2019		2018

Cash and cash equivalents	$	67,329	$	13,969	$	82,152
Restricted cash (included in non-current assets on the Consolidated Balance Sheets)		5,525		5,450		—
Total cash, cash equivalents and restricted cash	$	72,854	$	19,419	$	82,152

Property and Equipment, net

Computer equipment		2 years
Office furniture and equipment		5 years
Lab equipment		5 years
Leasehold improvements		Lesser of the remaining economic life of the asset or the lease-term

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.

At December 31, 2020, 2019, and 2018, the following outstanding common stock equivalents have been excluded from the calculation of net loss per share because their impact would be anti-dilutive.


	As of December 31,
	2020	2019	2018
Stock options	12,615,638	9,494,712	6,889,287
Series A Convertible Preferred Stock*	97,000	97,000	97,000
Series B Convertible Preferred Stock*	3,581,119	3,581,119	5,854,845
2020 ESPP	37,259	—	—
Restricted stock units	—	22,916	68,742
	16,331,016	13,195,747	12,909,874

*on an as-converted basis

Fair Value Measurements

Level 1—These are investments where values are based on unadjusted quoted prices for identical assets in an active market that the Company has the ability to access.

The Company does not have fair valued assets classified under Level 2 as of December 31, 2020 and 2019.

Level 3—These are financial instruments where values are derived from techniques in which one or more significant inputs are unobservable.

The Company does not have fair valued assets classified under Level 3 as of December 31, 2020 and 2019.

The Company’s financial instruments consist of cash and cash equivalents and short-term investments, all of which are reported at their respective fair value on its Consolidated Balance Sheets.


	Assets at Fair Value as of December 31, 2020
	Level 1		Level 2		Level 3		Total
U.S. treasury securities	$	470,109	$	—	$	—	$	470,109
U.S. government agency securities		91,999		—		—		91,999
Total	$	562,108	$	—	$	—	$	562,108


	Assets at Fair Value as of December 31, 2019
	Level 1		Level 2		Level 3		Total
US treasury securities	$	242,249	$	—	$	—	$	242,249
US government agency securities		50,863		—		—		50,863
Total	$	293,112	$	—	$	—	$	293,112

Use of Estimates

Principles of Consolidation

Income Taxes

Leases

For lease agreements entered into after the adoption of Topic 842 that include lease and non-lease components, such components are generally accounted for separately.

Stock-Based Compensation

The fair value of RSUs and RSAs is based on the closing price of the Company’s common stock on the grant date.

Cloud Computing Arrangements

Research and Development Expenses

General and Administrative Expenses

Concentrations

Recent Accounting Standards

Financial Instruments

Cloud Computing Arrangements

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.

Subsequent Events

Management of the Company evaluates events that have occurred after the balance sheet date through the date the financial statements are issued. See Note 14 - Subsequent Events.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2020

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Schedule of cash and cash equivalents and restricted cash


	December 31,		December 31,		December 31,
	2020		2019		2018

Cash and cash equivalents	$	67,329	$	13,969	$	82,152
Restricted cash (included in non-current assets on the Consolidated Balance Sheets)		5,525		5,450		—
Total cash, cash equivalents and restricted cash	$	72,854	$	19,419	$	82,152

Schedule Of Useful Lives Of Property Plant And Equipment [Table Text Block]

Computer equipment		2 years
Office furniture and equipment		5 years
Lab equipment		5 years
Leasehold improvements		Lesser of the remaining economic life of the asset or the lease-term

Schedule of Antidilutive securities excluded from computation of earnings per share


	As of December 31,
	2020	2019	2018
Stock options	12,615,638	9,494,712	6,889,287
Series A Convertible Preferred Stock*	97,000	97,000	97,000
Series B Convertible Preferred Stock*	3,581,119	3,581,119	5,854,845
2020 ESPP	37,259	—	—
Restricted stock units	—	22,916	68,742
	16,331,016	13,195,747	12,909,874

*on an as-converted basis

Schedule of assets measured at fair value


	Assets at Fair Value as of December 31, 2020
	Level 1		Level 2		Level 3		Total
U.S. treasury securities	$	470,109	$	—	$	—	$	470,109
U.S. government agency securities		91,999		—		—		91,999
Total	$	562,108	$	—	$	—	$	562,108


	Assets at Fair Value as of December 31, 2019
	Level 1		Level 2		Level 3		Total
US treasury securities	$	242,249	$	—	$	—	$	242,249
US government agency securities		50,863		—		—		50,863
Total	$	293,112	$	—	$	—	$	293,112

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2020

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Schedule of cash, money market funds and short-term investments

Cash equivalents, and short-term investments consist of the following (in thousands):


	December 31,		December 31,
	2020		2019

Cash equivalents - Money market funds	$	49,720	$	10,049

Cash equivalents total	$	49,720	$	10,049

Schedule of cost and fair value of cash equivalents and short-term investments

Cash equivalents in the tables above exclude cash demand deposits of $17.6 million and $3.9 million as of December 31, 2020 and 2019, respectively (in thousands).


	December 31,		December 31,
Short-term investments	2020		2019
U.S. treasury securities	$	470,109	$	242,249
U.S. government agency securities		91,999		50,863
Short-term investments total	$	562,108	$	293,112

The cost and fair value of cash equivalents and short-term investments at December 31, 2020 and 2019 were as follows (in thousands):


					Gross		Gross
			Accretion		Unrealized		Unrealized
As of December 31, 2020	Cost		(Amortization)		Gains		Losses		Fair Value
U.S. treasury securities	$	471,702	$	(1,594)	$	30	$	(29)	$	470,109
U.S. government agency securities		92,248		(267)		20		(2)		91,999
Total	$	563,950	$	(1,861)	$	50	$	(31)	$	562,108


					Gross		Gross
					Unrealized		Unrealized
As of December 31, 2019	Cost		Accretion		Gains		Losses		Fair Value
U.S. treasury securities	$	241,709	$	364	$	179	$	(3)	$	242,249
U.S. government agency securities		50,712		107		44		—		50,863
Total	$	292,421	$	471	$	223	$	(3)	$	293,112

PROPERTY AND EQUIPMENT (Tables)

12 Months Ended

Dec. 31, 2020

PROPERTY AND EQUIPMENT

Schedule of Property and equipment

Property and equipment, net consists of the following (in thousands):


	December 31,		December 31,
	2020		2019
Lab equipment	$	4,656	$	4,530
Leasehold improvements		2,573		2,372
Computer equipment		270		258
Office furniture and equipment		480		457
Construction in progress		56,758		5,417
Total Property and equipment, cost		64,737		13,034
Less: Accumulated depreciation and amortization		(5,578)		(4,498)
property and equipment, net	$	59,159	$	8,536

ACCRUED EXPENSES (Tables)

12 Months Ended

Dec. 31, 2020

ACCRUED EXPENSES

Schedule of accrued expenses

Accrued expenses consist of the following (in thousands):


	December 31,		December 31,
	2020		2019

Clinical related	$	15,661	$	4,692
Accrued payroll and employee related expenses		9,032		6,866
Commercial manufacturing facility related		4,342		—
Manufacturing related		3,266		2,184
Legal and related services		1,061		866
Accrued other		1,712		1,657
	$	35,074	$	16,265

STOCKHOLDERS' EQUITY (Tables)

12 Months Ended

Dec. 31, 2020

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 January 1, 2018	6,072,368	$	7.42
Issued	2,960,620		14.73
Exercised	(1,336,514)		7.45
Expired/Cancelled	(807,187)		10.04
Outstanding at December 31, 2018	6,889,287	$	10.25
Issued	4,166,600		14.73
Exercised	(727,492)		8.85
Expired/Cancelled	(833,683)		13.87
Outstanding at December 31, 2019	9,494,712	$	12.00
Issued	4,981,001		28.17
Exercised	(973,854)		9.92
Expired/Cancelled	(886,221)		18.67
Outstanding at December 31, 2020	12,615,638	$	18.08	7.81	$	358,726

Options exercisable at December 31, 2020	6,401,443	$	11.70	6.67	$	222,631

Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding and Exercisable


	Options Outstanding				Options Exercisable
		Weighted				Weighted
		Average	Weighted			Average	Weighted
		Remaining	Average			Remaining	Average
Range of Exercise	Number of	Contractual	Exercise Price		Number of	Contractual	Exercise Price
Prices	Shares	Life	Per Share		Shares	Life	Per Share
$ 5.05-$ 7.3	1,307,133	5.26	$	5.98	1,307,133	5.26	$	5.98
$ 7.4-$ 8.17	1,309,536	5.70		7.67	1,300,911	5.68		7.67
$ 8.3-$ 11.05	1,072,016	6.92		9.60	808,228	6.55		9.54
$ 11.15-$ 11.26	1,377,597	7.93		11.26	812,887	7.76		11.26
$ 11.44-$ 16.8	1,481,860	7.33		15.57	1,282,900	7.30		15.71
$ 16.94-$ 22.9	1,291,100	8.54		19.73	674,672	8.33		19.59
$ 23-$ 23.87	256,300	9.08		23.59	12,375	8.90		23.17
$ 23.88-$ 23.88	1,369,946	9.05		23.88	—	—		—
$ 23.93-$ 25.78	1,406,500	8.97		25.32	76,787	8.56		25.65
$ 27.5-$ 117	1,743,650	9.54		35.25	125,550	8.77		36.54
	12,615,638	7.81	$	18.08	6,401,443	6.67	$	11.70

Schedule of stock-based compensation



	Years Ended December 31,
	2020		2019		2018
Research and development	$	19,727	$	11,396	$	9,305
General and administrative		21,160		12,881		10,722
Total stock-based compensation expenses	$	40,887	$	24,277	$	20,027

Schedule of compensation cost for share-based payment arrangements, allocation of share-based compensation costs by plan



	Years Ended December 31,
	2020		2019		2018
Stock option expenses	$	40,714	$	23,964	$	19,758
Restricted stock unit expenses		112		313		269
2020 ESPP expenses		61		—		—
Total stock-based compensation expenses	$	40,887	$	24,277	$	20,027

Schedule of share-based payment award, stock options, valuation assumptions


	Stock Option			ESPP
	Years Ended December 31,
Assumptions:	2020	2019	2018	2020
Expected term (years)	5.18 - 6.19	6.14 - 6.06	6.50 - 5.13	0.50
Expected volatility	69.99% - 70.99%	71.62% - 70.63%	200.28% - 167.54%	54.90%
Risk-free interest rate	0.28% - 1.83%	2.59% - 1.62%	2.97% - 2.27%	0.09%
Expected dividend yield	0%	0%	0%	0%

INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2020

INCOME TAXES

Schedule of Deferred Tax Assets and Liabilities


	As of December 31,
	2020		2019
Deferred income tax asset:
Net operating loss carry forward	$	144,087	$	95,473
Stock-based compensation		11,364		8,851
Tax credit carry forwards		32,508		22,711
Lease liabilities		11,051		2,529
Depreciation and amortization		250		98
Reserves and accruals		1,866		1,410
Deferred tax assets before valuation allowance		201,126		131,072
Less: valuation allowance		(189,412)		(128,720)
Net deferred income tax assets		11,714		2,352
Deferred tax liabilities:
Depreciation and amortization		(11,714)		(2,352)
Net deferred tax assets (liabilities)	$	—	$	—

Schedule of Effective Income Tax Rate Reconciliation


	Years ended December 31,
	2020		2019		2018
Federal statutory tax rate	(21)	%	(21)	%	(21)	%
Orphan Drug & Research credits	(3)		(4)		(3)
Permanent and other differences	1		1		1
Tax rate change	—		—		—
State tax, net of federal benefit	—		(2)		(1)
	(23)	%	(26)	%	(24)	%
Valuation allowance	23	%	26	%	24	%
Effective tax rate	—	%	—	%	—	%

Schedule of Components of Income Tax Expense (Benefit)


	Years Ended December 31,
	2020		2019		2018
Federal:
Current	$	—	$	—	$	—
Deferred		(59,931)		(47,010)		(28,277)
State and Local
Current		—		—		—
Deferred		(760)		(3,564)		(2,020)
Change in Valuation Allowance		60,691		50,574		30,297
Total income tax expense (benefit)	$	—	$	—	$	—

Schedule of Unrecognized Tax Benefits


	Years Ended December 31,
	2020		2019		2018
Unrecognized benefit - beginning of period	$	10,038	$	6,344	$	4,111
Gross decreases - prior period tax positions		—		—		118
Gross increase current period tax positions		4,394		3,694		2,115
Unrecognized benefit - end of period	$	14,432	$	10,038	$	6,344

LEASES (Tables)

12 Months Ended

Dec. 31, 2020

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:


	December 31, 2020		December 31, 2019
Operating lease right-of-use assets	$	54,756	$	10,695
Operating lease liabilities
Current portion included in current liabilities		6,284		7,252
long-term portion included in non-current liabilities		45,375		4,248
Total Operating lease liabilities	$	51,659	$	11,500

Schedule of components of lease expenses


	For the Year			For the Year
	Ended			Ended
	December 31, 2020			December 31, 2019

Operating lease cost		8,728		$	9,213
Variable lease cost		5,585			5,801
Short-term lease cost		91			72
Total lease cost		14,404		$	15,086

Other information

Cash paid for amounts included in the measurement of lease liabilities included in Operating cashflows	$	8,372		$	8,622
Increase in right-of-use assets from the adoption of Topic 842	$	—		$	10,380
Right-of-use assets obtained from entering new leases	$	50,327		$	4,092
Increase in right-of-use assets from lease modifications	$	1,306		$	3,660
Weighted-average remaining lease terms (years)		16.76			1.74
Weighted-average discount rates		8.3	%		7.7	%

Schedule of minimum lease commitments

As of December 31, 2020, the maturities of the Company's operating lease liabilities were as follows (in thousands):


			CMO
	Facility		embedded
	leases		leases		Total
2021	$	3,912	$	6,288	$	10,200
2022		4,281		1,782		6,063
2023		4,286		—		4,286
2024		4,375		—		4,375
2025		4,281		—		4,281
Thereafter		74,206		—		74,206
Total lease payments	$	95,341	$	8,070	$	103,411
Less: Present value adjustment		(51,474)		(278)		(51,752)
Operating lease liabilities	$	43,867	$	7,792	$	51,659

QUARTERLY UNAUDITED RESULTS (Tables)

12 Months Ended

Dec. 31, 2020

QUARTERLY UNAUDITED RESULTS

Schedule of Quarterly Financial Information


	2020									2019
	(in thousands, except per share information)
	Q1		Q2		Q3		Q4			Q1	Q2		Q3		Q4
Revenue	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Net loss	$	(69,595)	$	(63,018)	$	(58,571)	$	(68,397)	$	(36,950)	$	(47,551)	$	(49,487)	$	(63,568)
Net loss per share, basic and diluted	$	(0.55)	$	(0.47)	$	(0.40)	$	(0.47)	$	(0.30)	$	(0.38)	$	(0.40)	$	(0.50)
Weighted average share used in computing net loss per share, basic and diluted		126,568		133,162		146,492		146,738		123,415		123,567		124,035		126,273

GENERAL ORGANIZATION AND BUSINESS (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended								12 Months Ended
	Oct. 17, 2018	Jan. 31, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
GENERAL ORGANIZATION AND BUSINESS
Net Loss			$ 68,397	$ 58,571	$ 63,018	$ 69,595	$ 63,568	$ 49,487	$ 47,551	$ 36,950	$ 259,581	$ 197,556	$ 123,580
Net cash used in operating activities											205,134	158,889	101,249
Proceeds from the issuance of common stock, net	$ 236,700	$ 162,000									567,043		398,817
Cash, cash equivalents and short-term investments			635,000								635,000
Cash equivalents, short-term investments, and restricted cash			67,300								67,300
Cash and cash equivalents			67,329				13,969				67,329	13,969	$ 82,152
Short-term investments			562,108				293,112				562,108	293,112
Restricted cash			$ 5,525				$ 5,450				$ 5,525	$ 5,450

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Cash, Cash equivalents and Restricted Cash (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Security deposit	$ 5,500,000
Security deposit for the benefit of the landlord for its commercial manufacturing facility	5,450,000
Security deposit for the benefit of utilities service provider	74,685
Letter of credit	1,000,000
Cash and cash equivalents	67,329,000	$ 13,969,000	$ 82,152,000
Restricted cash (included in non-current assets on the Consolidated Balance Sheets)	5,525,000	5,450,000
Total cash, cash equivalents and restricted cash	72,854,000	$ 19,419,000	$ 82,152,000	$ 145,373,000
Minimum
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Security deposit	$ 1,450,000

SUMMARY OF SIGNIFICANT ACCOUNTING PRACTICES - Useful lives, impairment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 0	$ 0
Computer equipment
Property, Plant and Equipment, Useful Life	2 years
Office furniture and equipment
Property, Plant and Equipment, Useful Life	5 years
Lab equipment
Property, Plant and Equipment, Useful Life	5 years
Leasehold improvements
Property, Plant and Equipment, Estimated Useful Lives	Lesser of the remaining economic life of the asset or the lease-term

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Loss per share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Antidilutive securities excluded from calculation of net loss per share	16,331,016	13,195,747	12,909,874
Stock option
Antidilutive securities excluded from calculation of net loss per share	12,615,638	9,494,712	6,889,287
Employee Stock Purchase Plan
Antidilutive securities excluded from calculation of net loss per share	37,259
Restricted stock units
Antidilutive securities excluded from calculation of net loss per share		22,916	68,742
Series A Convertible Preferred Stock
Antidilutive securities excluded from calculation of net loss per share	97,000	97,000	97,000
Series B Convertible Preferred Stock
Antidilutive securities excluded from calculation of net loss per share	3,581,119	3,581,119	5,854,845

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair value (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Level 2
Total	$ 0	$ 0
Level 3
Total	0	0
Fair Value, Measurements, Recurring
Total	562,108,000	293,112,000
Fair Value, Measurements, Recurring \| U.S. treasury securities
Total	470,109,000	242,249,000
Fair Value, Measurements, Recurring \| U.S. government agency securities
Total	91,999,000	50,863,000
Fair Value, Measurements, Recurring \| Level 1
Total	562,108,000	293,112,000
Fair Value, Measurements, Recurring \| Level 1 \| U.S. treasury securities
Total	470,109,000	242,249,000
Fair Value, Measurements, Recurring \| Level 1 \| U.S. government agency securities
Total	$ 91,999,000	$ 50,863,000

SUMMARY OF SIGNIFICANT ACCOUNTING PRACTICES - Concentrations, etc. (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) item	Dec. 31, 2019 USD ($)
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Number Of Financial Institutions \| item	3
Retained earnings \| $	$ (830,193)	$ (570,612)

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) segment
Number of operating segment \| segment	1
ASU 2018-15
Prepaid expenses and long-term assets	$ 1.4
Amortization of Intangible Assets	$ 0.2

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Money Market Funds
Cash equivalents total	$ 49,720	$ 10,049
Demand Deposits
Cash equivalents total	$ 17,600	$ 3,900

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS - Short-term investments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Short-term investments	$ 562,108	$ 293,112
U.S. treasury securities
Short-term investments	470,109	242,249
U.S. government agency securities
Short-term investments	$ 91,999	$ 50,863

CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS - Cost and fair value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cost	$ 563,950	$ 292,421
Accretion (Amortization)	(1,861)	471
Gross Unrealized Gains	50	223
Gross Unrealized Losses	(31)	(3)
Fair Value	562,108	293,112
U.S. treasury securities
Cost	471,702	241,709
Accretion (Amortization)	(1,594)	364
Gross Unrealized Gains	30	179
Gross Unrealized Losses	(29)	(3)
Fair Value	470,109	242,249
U.S. government agency securities
Cost	92,248	50,712
Accretion (Amortization)	(267)	107
Gross Unrealized Gains	20	44
Gross Unrealized Losses	(2)
Fair Value	$ 91,999	$ 50,863

PROPERTY AND EQUIPMENT - (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total Property and equipment, cost	$ 64,737	$ 13,034
Less: Accumulated depreciation and amortization	(5,578)	(4,498)
Property and equipment, net	59,159	8,536
Lab equipment
Property, Plant and Equipment [Line Items]
Total Property and equipment, cost	4,656	4,530
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total Property and equipment, cost	2,573	2,372
Computer equipment
Property, Plant and Equipment [Line Items]
Total Property and equipment, cost	270	258
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Total Property and equipment, cost	480	457
Construction in progress
Property, Plant and Equipment [Line Items]
Total Property and equipment, cost	$ 56,758	$ 5,417

PROPERTY AND EQUIPMENT - Other information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
PROPERTY AND EQUIPMENT
Depreciation	$ 1.1	$ 1.2	$ 1.0

ACCRUED EXPENSES (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ACCRUED EXPENSES
Clinical related	$ 15,661	$ 4,692
Accrued payroll and employee related expenses	9,032	6,866
Commercial manufacturing facility related	4,342
Manufacturing related	3,266	2,184
Legal and related services	1,061	866
Accrued other	1,712	1,657
Accrued expenses	$ 35,074	$ 16,265

STOCKHOLDERS' EQUITY (Details) - USD ($)				1 Months Ended				12 Months Ended
STOCKHOLDERS' EQUITY (Details) - USD ($)	Jan. 16, 2019	Jun. 01, 2016	Aug. 13, 2013	Jun. 30, 2020	Oct. 17, 2018	Jan. 31, 2018	Sep. 30, 2013	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 08, 2020	Jun. 10, 2019	Apr. 22, 2018	Aug. 16, 2016	Apr. 10, 2015	Nov. 30, 2014	Aug. 20, 2014	Aug. 19, 2014	Aug. 31, 2013	Oct. 14, 2011
Common Stock
Common stock issued, net of offering costs (in shares)							50,000
Common stock issued and retained by third party	17,500
Stock repurchased (in shares)	32,500
Proceeds from the issuance of common stock					$ 252,200,000	$ 172,500,000
Proceeds from the issuance of common stock, net					$ 236,700,000	$ 162,000,000.0		$ 567,043,000		$ 398,817,000
Common stock, par or stated value per share								$ 0.000041666	$ 0.000041666			$ 0.000041666
Common stock, shares authorized								300,000,000	300,000,000			150,000,000
Sale of stock, price per share					$ 9.97	$ 11.50
Vested		(137,500)
Maximum award per person per year (in shares)			300,000
Weighted average grant date fair value, options granted								$ 17.32	$ 9.48	$ 14.44
Intrinsic value of options exercised								$ 21,400,000	$ 5,300,000	$ 2,300,000
Share-based Compensation								$ 40,887,000	$ 24,277,000	$ 20,027,000
Other Income
Common Stock
Proceeds from the issuance of common stock, net	$ 335,000
Underwriter
Common Stock
Common stock, shares authorized												300,000,000
Common Stock
Common Stock
Common stock issued, net of offering costs (in shares)					25,300,000	15,000,000		19,475,806		40,300,000
Common Stock \| Issuance Of Common Stock Upon Conversion Of Preferred Stock
Common Stock
Conversion of stock, shares issued								2,273,726
IPO
Common Stock
Common stock issued, net of offering costs (in shares)				16,935,484	3,300,000	1,956,521
Share price (in dollars per share)				$ 31.00
Proceeds from the issuance of common stock, net				$ 567,000,000.0
IPO \| Underwriter
Common Stock
Common stock issued, net of offering costs (in shares)				2,540,322
Proceeds from the issuance of common stock				$ 603,700,000
Series A Convertible Preferred Stock
Common Stock
Preferred stock, shares authorized								17,000
Preferred stock, shares outstanding								194	194
Conversion of stock, shares issued								500
Conversion of Stock, shares converted								0	0
Series A Convertible Preferred Stock \| Common Stock
Common Stock
Common stock available in conversion, shares								97,000	97,000
Series A Convertible Preferred Stock \| Private Placement
Common Stock
Preferred stock, par or stated value per share								$ 1,000
Convertible price per shares								$ 2.00
Series B Convertible Preferred Stock
Common Stock
Preferred stock, shares authorized								11,500,000	11,500,000
Preferred stock, par or stated value per share								$ 0.001	$ 0.001
Convertible price per shares								$ 4.75
Preferred stock, shares outstanding								3,581,119	3,581,119
Conversion of Stock, shares converted								0
Series B Convertible Preferred Stock \| Issuance Of Common Stock Upon Conversion Of Preferred Stock
Common Stock
Conversion of stock, shares issued								2,273,726
Series B Convertible Preferred Stock \| Common Stock
Common Stock
Conversion of stock, shares issued								3,581,119	3,581,119
Series B Convertible Preferred Stock \| IPO
Common Stock
Preferred stock, shares authorized								11,500,000
Convertible price per shares								$ 4.75
Blank check
Common Stock
Preferred stock, shares authorized								50,000,000
Restricted stock units
Common Stock
Stock-based compensation expense								$ 100,000	$ 300,000	$ 300,000
Restricted stock units \| Chief Executive Officer
Common Stock
Granted		550,000
Granted		$ 5.87
Stock option
Common Stock
Unrecognized compensation cost recognition period								1 year 10 months 24 days
Total unrecognized compensation expense								$ 75,900,000
First Anniversary \| Chief Executive Officer
Common Stock
Vested		(137,500)
First Anniversary \| Restricted stock units
Common Stock
Vesting period		36 months
Satisfaction Of Clinical Trial Milestones \| Restricted stock units
Common Stock
Vested		(275,000)
2011 Equity Incentive Plan
Common Stock
Shares authorized																	1,900,000	1,700,000	1,700,000	180,000
Maximum award per person per year (in shares)			50,000
Number of shares available								11,240
2014 Equity Incentive Plan
Common Stock
Shares authorized															4,000,000	2,350,000
Number of shares available								61,575
The 2018 Plan
Common Stock
Shares authorized													6,000,000
Number of shares available								7,455,537
2020 ESPP
Common Stock
Shares authorized								500,000
Common stock, capital shares reserved for future issuance								0
Unrecognized compensation cost								$ 500,000
Unrecognized compensation cost recognition period								6 months
Percentage of purchase price								85.00%
Share-based Compensation								$ 60,000.00
Minimum \| The 2018 Plan
Common Stock
Shares authorized											6,000,000
Maximum \| 2014 Equity Incentive Plan
Common Stock
Shares authorized														9,000,000
Maximum \| The 2018 Plan
Common Stock
Shares authorized											14,000,000

STOCKHOLDERS' EQUITY - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Options
Outstanding, beginning balance	9,494,712	6,889,287	6,072,368
Granted	4,981,001	4,166,600	2,960,620
Exercised	(973,854)	(727,492)	(1,336,514)
Expired/Forfeited	(886,221)	(833,683)	(807,187)
Outstanding, ending balance	12,615,638	9,494,712	6,889,287
Options exercisable, number	6,401,443
Weighted Average Exercise Price
Outstanding, beginning balance	$ 12.00	$ 10.25	$ 7.42
Granted	28.17	14.73	14.73
Exercised	9.92	8.85	7.45
Expired/Forfeited	18.67	13.87	10.04
Outstanding, ending balance	18.08	$ 12.00	$ 10.25
Options exercisable, exercise price	$ 11.70
Weighted Average Remaining Contractual Life
Options outstanding, remaining term	7 years 9 months 21 days
Options exercisable, remaining term	6 years 8 months 1 day
Aggregate Intrinsic Value
Outstanding, end of period	$ 358,726
Exercisable	$ 222,631

STOCKHOLDERS' EQUITY - Exercise price (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, number	12,615,638	9,494,712	6,889,287	6,072,368
Options outstanding, remaining term	7 years 9 months 21 days
Options outstanding, exercise price	$ 18.08	$ 12.00	$ 10.25	$ 7.42
Options exercisable, number	6,401,443
Options exercisable, remaining term	6 years 8 months 1 day
Options exercisable, exercise price	$ 11.70
$ 5.05-$ 7.3
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	5.05
Options exercise price, upper limit	$ 7.3
Options outstanding, number	1,307,133
Options outstanding, remaining term	5 years 3 months 3 days
Options outstanding, exercise price	$ 5.98
Options exercisable, number	1,307,133
Options exercisable, remaining term	5 years 3 months 3 days
Options exercisable, exercise price	$ 5.98
$ 7.4-$ 8.17
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	7.4
Options exercise price, upper limit	$ 8.17
Options outstanding, number	1,309,536
Options outstanding, remaining term	5 years 8 months 12 days
Options outstanding, exercise price	$ 7.67
Options exercisable, number	1,300,911
Options exercisable, remaining term	5 years 8 months 4 days
Options exercisable, exercise price	$ 7.67
$ 8.3-$ 11.05
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	8.3
Options exercise price, upper limit	$ 11.05
Options outstanding, number	1,072,016
Options outstanding, remaining term	6 years 11 months 1 day
Options outstanding, exercise price	$ 9.60
Options exercisable, number	808,228
Options exercisable, remaining term	6 years 6 months 18 days
Options exercisable, exercise price	$ 9.54
$ 11.15-$ 11.26
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	11.15
Options exercise price, upper limit	$ 11.26
Options outstanding, number	1,377,597
Options outstanding, remaining term	7 years 11 months 4 days
Options outstanding, exercise price	$ 11.26
Options exercisable, number	812,887
Options exercisable, remaining term	7 years 9 months 3 days
Options exercisable, exercise price	$ 11.26
$ 11.44-$ 16.8
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	11.44
Options exercise price, upper limit	$ 16.8
Options outstanding, number	1,481,860
Options outstanding, remaining term	7 years 3 months 29 days
Options outstanding, exercise price	$ 15.57
Options exercisable, number	1,282,900
Options exercisable, remaining term	7 years 3 months 18 days
Options exercisable, exercise price	$ 15.71
$ 16.94-$ 22.9
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	16.94
Options exercise price, upper limit	$ 22.9
Options outstanding, number	1,291,100
Options outstanding, remaining term	8 years 6 months 14 days
Options outstanding, exercise price	$ 19.73
Options exercisable, number	674,672
Options exercisable, remaining term	8 years 3 months 29 days
Options exercisable, exercise price	$ 19.59
$ 23-$ 23.87
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	23
Options exercise price, upper limit	$ 23.87
Options outstanding, number	256,300
Options outstanding, remaining term	9 years 29 days
Options outstanding, exercise price	$ 23.59
Options exercisable, number	12,375
Options exercisable, remaining term	8 years 10 months 24 days
Options exercisable, exercise price	$ 23.17
$ 23.88-$ 23.88
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	23.88
Options exercise price, upper limit	$ 23.88
Options outstanding, number	1,369,946
Options outstanding, remaining term	9 years 18 days
Options outstanding, exercise price	$ 23.88
Options exercisable, remaining term	0 years
$ 23.93-$ 25.78
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	$ 23.93
Options exercise price, upper limit	$ 25.78
Options outstanding, number	1,406,500
Options outstanding, remaining term	8 years 11 months 19 days
Options outstanding, exercise price	$ 25.32
Options exercisable, number	76,787
Options exercisable, remaining term	8 years 6 months 21 days
Options exercisable, exercise price	$ 25.65
$ 27.5-$ 117
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options exercise price, lower limit	27.5
Options exercise price, upper limit	$ 117
Options outstanding, number	1,743,650
Options outstanding, remaining term	9 years 6 months 14 days
Options outstanding, exercise price	$ 35.25
Options exercisable, number	125,550
Options exercisable, remaining term	8 years 9 months 7 days
Options exercisable, exercise price	$ 36.54

STOCKHOLDERS' EQUITY - Stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total stock-based compensation expenses	$ 40,887	$ 24,277	$ 20,027
Research and development
Total stock-based compensation expenses	19,727	11,396	9,305
General and administrative
Total stock-based compensation expenses	$ 21,160	$ 12,881	$ 10,722

STOCKHOLDERS' EQUITY - Stock-based compensation by instrument (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Total stock-based compensation expenses	$ 40,887	$ 24,277	$ 20,027
Stock option
Total stock-based compensation expenses	40,714	23,964	19,758
Restricted stock award expenses
Total stock-based compensation expenses	112	$ 313	$ 269
2020 ESPP
Total stock-based compensation expenses	$ 61

STOCKHOLDERS' EQUITY - Assumptions (Details)	12 Months Ended
STOCKHOLDERS' EQUITY - Assumptions (Details)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock option
Expected dividend yield	0.00%	0.00%	0.00%
Stock option \| Minimum
Expected term (years)	5 years 2 months 4 days	6 years 1 month 20 days	6 years 6 months
Expected volatility	69.99%	71.62%	200.28%
Risk-free interest rate	0.28%	2.59%	2.97%
Stock option \| Maximum
Expected term (years)	6 years 2 months 8 days	6 years 21 days	5 years 1 month 17 days
Expected volatility	70.99%	70.63%	167.54%
Risk-free interest rate	1.83%	1.62%	2.27%
2020 ESPP
Expected term (years)	6 months
Expected volatility	54.90%
Risk-free interest rate	0.09%
Expected dividend yield	0.00%

EMPLOYEE BENEFIT PLAN (Details) - USD ($) $ in Millions	12 Months Ended
EMPLOYEE BENEFIT PLAN (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
EMPLOYEE BENEFIT PLAN
Defined Contribution Plan, Cost	$ 1.2	$ 0.9	$ 0.5

INCOME TAXES (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax asset:
Net operating loss carry forward	$ 144,087	$ 95,473
Stock-based compensation	11,364	8,851
Tax credit carryforwards	32,508	22,711
Lease liabilities	11,051	2,529
Depreciation and Amortization	250	98
Reserves and accruals	1,866	1,410
Deferred tax assets before valuation allowance	201,126	131,072
Less: valuation allowance	(189,412)	(128,720)
Net deferred income tax assets	11,714	2,352
Deferred tax liabilities:
Depreciation and amortization	(11,714)	(2,352)
Net deferred tax assets (liabilities)	$ 0	$ 0

INCOME TAXES - Rate reconciliation (Details)	12 Months Ended
INCOME TAXES - Rate reconciliation (Details)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES
Federal statutory tax rate	(21.00%)	(21.00%)	(21.00%)
Orphan Drug & Research credits	(3.00%)	(4.00%)	(3.00%)
Permanent and other differences	1.00%	1.00%	1.00%
State tax, net of federal benefit		(2.00%)	(1.00%)
Effective Income Tax Rate Reconciliation Expected Rate Total	(23.00%)	(26.00%)	(24.00%)
Valuation allowance	23.00%	26.00%	24.00%

INCOME TAXES - Expense components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal:
Current	$ 0	$ 0	$ 0
Deferred	(59,931)	(47,010)	(28,277)
State and Local
Current	0	0	0
Deferred	(760)	(3,564)	(2,020)
Change in Valuation Allowance	60,691	50,574	30,297
Total income tax expense (benefit)	$ 0	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

INCOME TAXES - Unrecognized benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES
Unrecognized benefit-beginning of period	$ 10,038	$ 6,344	$ 4,111
Gross decreases-prior period tax positions	0	0	118
Gross increases-current period tax positions	4,394	3,694	2,115
Unrecognized benefit-end of period	$ 14,432	$ 10,038	$ 6,344

INCOME TAXES - Other information (Details) - USD ($)	12 Months Ended
INCOME TAXES - Other information (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Operating Loss Carry forwards Having Definite Expire life Value	$ 142,400,000
Operating Loss Carry forwards Having Indefinite Expire life Value	520,000,000.0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	60,700,000	$ 50,600,000	$ 30,300,000
Interest or penalties on unpaid tax	0	$ 0	$ 0
Domestic Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards	662,400,000
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards	$ 128,900,000

LICENSES AND AGREEMENTS (Details) $ in Thousands		1 Months Ended					12 Months Ended
LICENSES AND AGREEMENTS (Details) $ in Thousands	Jun. 28, 2014 USD ($)	Apr. 30, 2017 USD ($)	Dec. 31, 2016	Nov. 30, 2016 item	Aug. 31, 2016 USD ($)	Aug. 31, 2011 item	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	May 31, 2017 USD ($)
Research and development expenses							$ 201,727	$ 166,023	$ 99,828
Payments For Clinical Trials Agreement							2,500
Strategic Alliance Agreement
Research and development expenses							1,100	3,400	800
Prepaid expense, current										$ 1,400
Research Collaboration And Clinical Grant Agreement
Research and development expenses							600	700	1,200
Maximum \| Strategic Alliance Agreement
Research and development arrangement, contract to perform for others, costs incurred, gross		$ 14,200
Novartis Pharma AG - License Agreement [Member]
Research and development expenses							10,000
Cooperative Research and Development Agreement
Agreement term					5 years	5 years
Research and development expenses							2,000	2,200	2,000
Number Of Indications Under Agreement \| item						4
Additional milestone payable					$ 500
Notification Period To Terminate Agreement					60 days
WuXi Apptech, Inc - Manufacturing and Services Agreement
Agreement term				3 years
Research and development expenses							20,600	28,400	15,100
Number Of Statements Of Work \| item				2
Number Of Suites Under The Agreement \| item				2
Moffitt License Agreement Two
Research and development expenses							100	$ 100	100
Payments for upfront licensing fee									$ 100
Additional milestone payable							400
Moffitt License Agreement One
Agreement term	20 years
Payments for upfront licensing fee	$ 100
Research Collaboration And Clinical Grant Agreements With Moffitt
Agreement term			3 years
Cellectis S.A
Research and development expenses							$ 400

LEASES - Additional information (Details)														1 Months Ended		12 Months Ended
LEASES - Additional information (Details)	Oct. 31, 2020 USD ($)	Sep. 01, 2020 USD ($)	Aug. 01, 2020 USD ($) ft²	Jul. 31, 2020 USD ($)	Oct. 24, 2019 USD ($)	Jun. 19, 2019 USD ($) ft²	May 28, 2019 USD ($) ft²	May 01, 2019 USD ($)	Nov. 02, 2018 USD ($)	Oct. 19, 2018 USD ($) ft²	Apr. 20, 2018 USD ($)	Apr. 28, 2017 USD ($) ft²	Aug. 04, 2016 USD ($) ft²	Jul. 31, 2017 USD ($)	Dec. 31, 2014 ft²	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Jun. 30, 2020 USD ($) ft²	May 02, 2019 USD ($) ft²	Oct. 31, 2018 ft²	Jun. 05, 2017 USD ($)	Sep. 30, 2016 USD ($) ft²	Apr. 30, 2015 USD ($) ft²
Term of contract (in years)																12 months
Option to extend							option to extend
Monthly lease payments										$ 59,000						$ 103,411,000
First year																10,200,000
Second year																6,063,000
Lease Expiration Term										30 months
Monthly lease payments																8,372,000	$ 8,622,000
Operating lease liabilities																51,659,000	11,500,000
Operating lease right-of-use assets																$ 54,756,000	$ 10,695,000
Basis spread on operating lease (as a percent)										3.00%
Weighted average remaining lease term (in years)																16 years 9 months 3 days	1 year 8 months 26 days
Weighted average discount rate (as a percent)																8.30%	7.70%
Philadelphia, Pennsylvania
Operating expenses			$ 6,500
Area of land \| ft²			2,965
Land \| San Carlos, California
Area of land \| ft²																				11,449
Facility leases
Monthly lease payments																$ 95,341,000
First year																3,912,000
Second year																4,281,000
Operating lease liabilities																$ 43,867,000
Facility leases \| Tampa, Florida
Term of contract (in years)															5 years
Option to extend															option to extend
Renewal term (in years)															5 years
Monthly lease payments																		$ 34,500				$ 20,000	$ 20,500
Area of land \| ft²															5,115			13,139				8,673	6,043
Facility leases \| San Carlos, California
Additional space of lease \| ft²						8,110
First year						$ 39,000
Second year						$ 40,000
Area of land \| ft²												11,449
Facility leases \| New York
Operating expenses	$ 4,000	$ 4,000		$ 4,000	$ 4,000			$ 4,000
Rent expense									$ 4,000
Facility leases \| Office Space \| San Carlos, California
Monthly lease payments												$ 26,000	$ 38,000
Lease Expiration Term													54 months
Operating Leases, Rent Expense, Minimum Rentals												$ 26,000
Area of land \| ft²						20,432				12,322			8,733
Facility leases \| Office Space \| New York
Monthly lease payments																					$ 9,000
Operating Leases, Rent Expense, Minimum Rentals														$ 18,000
Rent expense											$ 7,000
Office lease for first year \| Office Space \| Philadelphia, Pennsylvania
Monthly lease payments																			$ 2,000
Area of land \| ft²																			1,500
Office lease for next three years \| Philadelphia, Pennsylvania
Basis spread on operating lease (as a percent)																			2.50%
Office lease for next three years \| Office Space \| Philadelphia, Pennsylvania
Term of contract (in years)																			3 years
Monthly lease payments																			$ 11,063
Area of land \| ft²																			4,500
Commercial Manufacturing Facility Agreement
Renewal term (in years)							359 months
Monthly lease payments							$ 320,000
Prior written notice period (in months)							18 months
Minimum annual increase in basis spread on variable rate (as a percent)							2.00%
Maximum annual increase in basis spread on variable rate (as a percent)							75.00%
Operating expenses							$ 72,000
Operating lease liabilities																			$ 41,300,000
Operating lease right-of-use assets																			$ 45,700,000
Basis spread on operating lease (as a percent)							2.00%
Commercial Manufacturing Facility Agreement \| Office Space
Area of land \| ft²							136,000

LEASES - Company's right-of-use asset and lease liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
LEASES
Operating lease right-of-use assets	$ 54,756	$ 10,695
Operating lease liabilities
Current portion included in current liabilities	6,284	7,252
Long-term portion included in non-current liabilities	45,375	4,248
Total Operating lease liabilities	$ 51,659	$ 11,500

LEASES - components of lease expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
LEASES
Operating lease cost	$ 8,728	$ 9,213
Variable lease cost	5,585	5,801
Short-term lease cost	91	72
Total lease cost	14,404	15,086
Cash paid for amounts included in the measurement of lease liabilities included in Operating cashflows	8,372	8,622
Increase in right-of-use assets from the adoption of Topic 842		10,380
Right-of-use assets obtained from entering new leases	50,327	4,092
Increase in right-of-use assets from lease modifications	$ 1,306	$ 3,660
Weighted-average remaining lease terms (years)	16 years 9 months 3 days	1 year 8 months 26 days
Weighted-average discount rates	8.30%	7.70%

LEASES - maturities of the Company's operating lease liabilities (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019	Oct. 19, 2018
2021	$ 10,200,000
2022	6,063,000
2023	4,286,000
2024	4,375,000
2025	4,281,000
Thereafter	74,206,000
Total lease payments	103,411,000		$ 59,000
Less: Present value adjustment	(51,752,000)
Operating lease liabilities	51,659,000	$ 11,500,000
Facility leases
2021	3,912,000
2022	4,281,000
2023	4,286,000
2024	4,375,000
2025	4,281,000
Thereafter	74,206,000
Total lease payments	95,341,000
Less: Present value adjustment	(51,474,000)
Operating lease liabilities	43,867,000
CMO embedded leases
2021	6,288,000
2022	1,782,000
Total lease payments	8,070,000
Less: Present value adjustment	(278,000)
Operating lease liabilities	$ 7,792,000

LEGAL PROCEEDINGS (Details)					1 Months Ended			12 Months Ended
LEGAL PROCEEDINGS (Details)	May 12, 2020 USD ($)	Jul. 05, 2018 item	Jun. 13, 2017 USD ($) shares	Jun. 03, 2016 USD ($)	Mar. 31, 2013	Nov. 30, 2012 USD ($)	Jun. 30, 2012 USD ($)	Dec. 31, 2020 shares	Dec. 31, 2019 shares	Dec. 31, 2018 shares	Apr. 08, 2016 USD ($)
Damages claimed				$ 500,000
Equity Claim	$ 47,420
Granted \| shares								4,981,001	4,166,600	2,960,620
Common stock issued upon exercise of stock options (in shares) \| shares								973,854	727,492	1,336,514
Solomon Capital LLC Litigation
Proceeds from related party debt						$ 100,000	$ 200,000
Debt instrument, convertible, number of equity instruments								1,110
Stockholders' Equity Note, Stock Split, Conversion Ratio					0.01
Twenty Eleven Equity Incentive Plan
Common stock issued upon exercise of stock options (in shares) \| shares								200,000
Steven Fischkoff
Loss Contingency, Claims Dismissed, Number \| item		2
Granted \| shares			150,000
Severance pay and retention bonus			$ 300,000
Minimum
Estimate of possible loss											$ 1,500,000
Commercial Paper \| Solomon Capital LLC Litigation
Face amount											$ 200,000

QUARTERLY UNAUDITED RESULTS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
QUARTERLY UNAUDITED RESULTS
Net Loss	$ (68,397)	$ (58,571)	$ (63,018)	$ (69,595)	$ (63,568)	$ (49,487)	$ (47,551)	$ (36,950)	$ (259,581)	$ (197,556)	$ (123,580)
Net loss per share, basic and diluted	$ (0.47)	$ (0.40)	$ (0.47)	$ (0.55)	$ (0.50)	$ (0.40)	$ (0.38)	$ (0.30)	$ (1.88)	$ (1.59)	$ (1.27)
Weighted average share used in computing net loss per share, basic and diluted	146,738	146,492	133,162	126,568	126,273	124,035	123,567	123,415	138,301	124,336	97,277

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands			12 Months Ended
	Sep. 14, 2017	Sep. 14, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price			$ 28.17	$ 14.73	$ 14.73
Share-based Compensation Arrangement by Share-based Payment Award, Terms of Award		The granted stock options vest in 12 quarterly installments (with 1/12th of the option shares having vested on the date of grant).
Share-based Compensation			$ 40,887	$ 24,277	$ 20,027
Consulting Agreement
Share-based Compensation			$ 200	$ 400	$ 700
Board of Directors Chairman
Term of consulting agreement (in years)	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	150	150
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price	$ 7.30
Vesting period	3 years

SUBSEQUENT EVENT (Details)	Feb. 03, 2021 USD ($) ft²	Jun. 19, 2019 ft²	May 28, 2019	Dec. 31, 2020 USD ($)	Oct. 19, 2018 USD ($) ft²	Apr. 28, 2017 USD ($) ft²	Aug. 04, 2016 USD ($) ft²
Term of contract (in years)				12 months
Option to extend			option to extend
Monthly lease payments \| $				$ 103,411,000	$ 59,000
New Headquarters Lease \| Office Space \| Subsequent Event
Area of land \| ft²	49,918
Term of contract (in years)	120 months
Renewal term (in years)	60 months
Rent commencement period delayed (in days)	210 days
Monthly lease payments \| $	$ 279,540.80
Base rent annual increase percentage	3.00%
New Headquarters Lease \| Office Space \| Subsequent Event \| San Carlos, California
Option to extend	true
Facility leases
Monthly lease payments \| $				$ 95,341,000
Facility leases \| San Carlos, California
Area of land \| ft²						11,449
Additional Area of Space Under Amended Lease \| ft²		8,110
Facility leases \| Office Space \| San Carlos, California
Area of land \| ft²		20,432			12,322		8,733
Monthly lease payments \| $						$ 26,000	$ 38,000
Suite 100 and Suite 125 Amendment \| Office Space \| Subsequent Event \| San Carlos, California
Monthly lease payments \| $	$ 103,181.60
Additional Area of Space Under Amended Lease \| ft²	20,432
Suite 100 and Suite 125 Amendment \| Office Space \| Subsequent Event \| Minimum
Renewal term (in years)	1 month
Suite 100 and Suite 125 Amendment \| Office Space \| Subsequent Event \| Maximum
Renewal term (in years)	6 months
Suite 150 Second Amendment \| Office Space \| Subsequent Event \| San Carlos, California
Option to extend	true
Monthly lease payments \| $	$ 44,101.65
Additional Area of Space Under Amended Lease \| ft²	8,733
Suite 150 Second Amendment \| Office Space \| Subsequent Event \| Minimum
Renewal term (in years)	1 month
Suite 150 Second Amendment \| Office Space \| Subsequent Event \| Maximum \| San Carlos, California
Renewal term (in years)	6 months

SUBSEQUENT EVENT - Economic Stimulus Program Loan (Details) - USD ($)		12 Months Ended
	Jan. 26, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Lease, Payments		$ 8,372,000	$ 8,622,000
Subsequent Event \| Job Creation Loan
Face amount	$ 1,000,000.0
Loan term	5 years
Loan amount forgiven	$ 2,000
Debt Instrument	5 years
Subsequent Event \| Minimum \| Job Creation Loan
Debt Instrument, Number of Hours Per Week, Loan Forgiven	35 hours
Minimum average salary	$ 80,000

SUBSEQUENT EVENT - Entry Into a Material Definitive Agreement (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 08, 2021	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2019	Jun. 10, 2019
Subsequent Event [Line Items]
Stock issued during period, value, new issues		$ 567,043	$ 398,817
Common stock, par or stated value per share		$ 0.000041666		$ 0.000041666	$ 0.000041666
Maximum \| Sales Agreement with Jefferries LLC \| Subsequent Event
Subsequent Event [Line Items]
Percentage of commission on gross sale proceeds	3.00%
Maximum \| Sales Agreement with Jefferries LLC \| At the Market Offering \| Subsequent Event
Subsequent Event [Line Items]
Stock issued during period, value, new issues	$ 350,000
Common stock, par or stated value per share	$ 0.000041666