Checkpoint Therapeutics (CKPT) 10-K12 Mar 212020 FY Annual reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2020	Mar. 05, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2020
Entity File Number	001-38128
Entity Registrant Name	Checkpoint Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-2568632
Entity Address, Address Line One	2 Gansevoort Street
Entity Address, Address Line Two	9th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10014
City Area Code	781
Local Phone Number	652-4500
Title of 12(b) Security	Common Stock, par value $0.0001 per
Trading Symbol	CKPT
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Central Index Key	0001651407
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Public Float			$ 80,720,490
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
IcfrAuditorAttestationFlag	false
Common Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		68,212,354
Class A Common Shares [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		7,000,000

BALANCE SHEETS

BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 40,772	$ 26,077
Prepaid expenses and other assets	1,804	863
Other receivables - related party	20	26
Total current assets	42,596	26,966
Total Assets	42,596	26,966
Current Liabilities:
Accounts payable and accrued expenses	6,367	7,257
Accounts payable and accrued expenses - related party	850	862
Total current liabilities	7,217	8,119
Total Liabilities	7,217	8,119
Commitments and Contingencies
Stockholders' Equity
Common Stock Value	6	5
Common stock issuable, 1,742,449 and 1,459,305 shares as of December 31, 2020 and December 31, 2019, respectively	4,617	2,510
Additional paid-in capital	173,947	136,442
Accumulated deficit	143,192	120,111
Total Stockholders' Equity	35,379	18,847
Total Liabilities and Stockholders' Equity	42,596	26,966
Class A Common Shares [Member]
Stockholders' Equity
Common Stock Value	1	1
Total Stockholders' Equity	$ 1	$ 1

BALANCE SHEETS (Parenthetical)

BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Common Stock, Par or Stated Value Per Share	$ 0.0001	$ 0.0001
Common Stock, Shares Authorized	95,000,000
Common Stock, Shares, Issued	62,420,439	47,004,764
Common Stock, Shares, Outstanding	62,420,439	47,004,764
Common Stock, Shares Subscribed but Unissued	1,742,449	1,459,305
Class A Common Shares [Member]
Common Stock, Shares, Issued	7,000,000	7,000,000
Common Stock, Shares, Outstanding	7,000,000	7,000,000

STATEMENTS OF OPERATIONS

STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
STATEMENTS OF OPERATIONS
Revenue - related party	$ 1,069	$ 1,708
Operating expenses:
Research and development	16,352	19,325
General and administrative	7,918	7,233
Total operating expenses	24,270	26,558
Loss from operations	(23,201)	(24,850)
Other income
Interest income	120	136
Total other income	120	136
Net Loss	$ (23,081)	$ (24,714)
Loss per Share:
Basic and diluted net loss per common share outstanding	$ (0.41)	$ (0.70)
Basic and diluted weighted average number of common shares outstanding	55,830,582	35,303,955

STATEMENTS OF STOCKHOLDERS' EQU

STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Common Shares [Member]	Common Stock Issuable [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Class A Common Shares [Member]	Total
Balances at Dec. 31, 2018	$ 3,000	$ 1,748,000	$ 105,451,000	$ (95,397,000)	$ 1,000	$ 11,806,000
Balances (in Shares) at Dec. 31, 2018	27,076,154				7,000,000
Issuance of common shares, net of offering costs - At-the-market offering	$ 0	0	7,813,000	0	$ 0	7,813,000
Issuance of common shares, net of offering costs - At-the-market offering (in Shares)	2,273,189				0
Issuance of common shares, net of offering costs - Public offering	$ 2,000	0	17,571,000	0	$ 0	17,573,000
Issuance of common shares, net of offering costs - Public offering (in Shares)	15,400,000				0
Stock-based compensation expense	$ 0	0	3,121,000	0	$ 0	3,121,000
Stock-based compensation expense (in Shares)	779,652				0
Issuance of common shares - Founders Agreement	$ 0	(1,748,000)	2,486,000	0	$ 0	738,000
Issuance of common shares - Founders Agreement (in Shares)	1,402,244				0
Common shares issuable - Founders Agreement	$ 0	2,510,000	0	0	$ 0	2,510,000
Common shares issuable - Founders Agreement (in Shares)	0				0
Exercise of warrants	$ 0	0	0	0	$ 0	0
Exercise of warrants (in Shares)	73,525				0
Net loss	$ 0	0	0	(24,714,000)	$ 0	(24,714,000)
Balances at Dec. 31, 2019	$ 5,000	2,510,000	136,442,000	(120,111,000)	$ 1,000	18,847,000
Balances (in Shares) at Dec. 31, 2019	47,004,764				7,000,000
Issuance of common shares, net of offering costs - At-the-market offering	$ 0	0	12,393,000	0	$ 0	12,393,000
Issuance of common shares, net of offering costs - At-the-market offering (in Shares)	5,104,234				0
Issuance of common shares, net of offering costs - Public offering	$ 1,000	0	18,908,000	0	$ 0	18,909,000
Issuance of common shares, net of offering costs - Public offering (in Shares)	7,321,429				0
Stock-based compensation expense	$ 0	0	2,780,000	0	$ 0	2,780,000
Stock-based compensation expense (in Shares)	1,117,340				0
Issuance of common shares - Founders Agreement	$ 0	(2,510,000)	3,411,000	0	$ 0	901,000
Issuance of common shares - Founders Agreement (in Shares)	1,769,930				0
Common shares issuable - Founders Agreement	$ 0	4,617,000	0	0	$ 0	4,617,000
Common shares issuable - Founders Agreement (in Shares)	0				0
Exercise of warrants	$ 0	0	13,000	0	$ 0	13,000
Exercise of warrants (in Shares)	102,742				0
Net loss	$ 0	0	0	(23,081,000)	$ 0	(23,081,000)
Balances at Dec. 31, 2020	$ 6,000	$ 4,617,000	$ 173,947,000	$ (143,192,000)	$ 1,000	$ 35,379,000
Balances (in Shares) at Dec. 31, 2020	62,420,439				7,000,000

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities:
Net loss	$ (23,081)	$ (24,714)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,780	3,121
Issuance of common shares - Founders Agreement	901	738
Common shares issuable - Founders Agreement	4,617	2,510
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(941)	509
Other receivables - related party	6	1,506
Accounts payable and accrued expenses	833	5,043
Net cash used in operating activities	(16,551)	(21,373)
Cash Flows from Financing Activities:
Proceeds from issuance of common stock - Public offering	20,500	19,560
Offering costs for the issuance of common stock - Public offering	(1,660)	(1,918)
Proceeds from issuance of common stock - At-the-market offering	12,767	8,011
Offering costs for the issuance of common stock - At-the-market offering	(374)	(198)
Proceeds from the exercise of warrants	13	0
Net cash provided by financing activities	31,246	25,455
Net increase in cash and cash equivalents	14,695	4,082
Cash and cash equivalents at beginning of period	26,077	21,995
Cash and cash equivalents at end of period	40,772	26,077
Supplemental disclosure of noncash investing and financing activities:
Issuance of common shares - Founders Agreement	2,510	1,748
Issuance of common shares - Public offering (offering costs incurred but not paid)	$ 0	$ 69

Organization and Description of

Organization and Description of Business Operations	12 Months Ended
Organization and Description of Business Operations	Dec. 31, 2020
Organization and Description of Business Operations
Organization and Description of Business Operations	Note 1 - Organization and Description of Business Operations Checkpoint Therapeutics, Inc. (the “Company” or “Checkpoint”) was incorporated in Delaware on November 10, 2014. Checkpoint is a clinical-stage immunotherapy and targeted oncology company focused on the acquisition, development and commercialization of novel treatments for patients with solid tumor cancers. The Company may acquire rights to these technologies by licensing the rights or otherwise acquiring an ownership interest in the technologies, funding their research and development and eventually either out-licensing or bringing the technologies to market. The Company may also enter into collaboration agreements with third and related parties including sponsored research agreements to develop these technologies for liquid tumors while retaining the rights in solid tumors. The Company is a majority-controlled subsidiary of Fortress Biotech, Inc. (“Fortress”). The Company’s common stock is listed on the NASDAQ Capital Market and trades under the symbol “CKPT.” Liquidity and Capital Resources The Company has incurred substantial operating losses since its inception and expects to continue to incur significant operating losses for the foreseeable future and may never become profitable. As of December 31, 2020, the Company had an accumulated deficit of $143.2 million. In September 2020, the Company completed an underwritten public offering in which it sold 7,321,429 shares of its common stock at a price of $2.80 per share for gross proceeds of approximately $20.5 million. Total net proceeds from the offering were approximately $18.9 million, net of underwriting discounts and offering expenses of approximately $1.6 million. During the year ended December 31, 2020, the Company sold a total of 5,104,234 shares of common stock under an At-the-Market Issuance Sales Agreement ("ATM") for aggregate total gross proceeds of approximately $12.8 million at an average selling price of $2.50 per share, resulting in net proceeds of approximately $12.4 million after deducting commissions and other transaction costs. The Company expects to continue to use the proceeds from previous financing transactions primarily for general corporate purposes, which may include financing the Company’s growth, developing new or existing product candidates, and funding capital expenditures, acquisitions and investments. The Company currently anticipates that its cash and cash equivalents balances are sufficient to fund its anticipated operating cash requirements for at least one year from the date of issuance of this Annual Report on Form 10-K. The Company will be required to expend significant funds in order to advance the development of its product candidates. The Company’s estimate as to how long it expects its existing cash to be able to continue to fund its operations is based on assumptions that may prove to be wrong, and it could use its available capital resources sooner than it currently expects. Further, changing circumstances, some of which may be beyond its control, could cause the Company to consume capital faster than it currently anticipates, and it may need to seek additional funds sooner than planned. Accordingly, the Company will be required to obtain further funding through equity offerings, debt financings, collaborations and licensing arrangements or other sources. Further financing may not be available to it on acceptable terms, or at all. The Company’s failure to raise capital as and when needed would have a negative impact on its financial condition and its ability to pursue its business strategy and may be forced to curtail or cease operations. In addition to the foregoing, based on the Company's current assessment, the Company does not expect any material impact on its long-term development timeline and its liquidity due to the worldwide spread of the coronavirus ("COVID-19"). However, the Company is continuing to assess the effect on its operations by monitoring the spread of COVID-19, as well as the effect of the COVID-19 pandemic on the Company's clients, vendors, and business partners, and the actions implemented to combat the virus throughout the world.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
Significant Accounting Policies	Dec. 31, 2020
Significant Accounting Policies
Significant Accounting Policies	Note 2 - Significant Accounting Policies Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. The Company has no subsidiaries. Segments Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating and reporting segment. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. Other Receivables - Related Party Other receivables includes amounts due to the Company from TG Therapeutics, Inc. (“TGTX”), a related party, and are recorded at the invoiced amount. Research and Development Costs Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Upfront and milestone payments due to third parties that perform research and development services on the Company’s behalf will be expensed as services are rendered or when the milestone is achieved. Research and development costs primarily consist of personnel related expenses, including salaries, benefits, travel, and other related expenses, stock-based compensation, payments made to third parties for license and milestone costs related to in-licensed products and technology, payments made to third party contract research organizations for preclinical and clinical studies, investigative sites for clinical trials, consultants, the cost of acquiring and manufacturing clinical trial materials, costs associated with regulatory filings, laboratory costs and other supplies. In accordance with Accounting Standards Codification (“ASC”) 730-10-25-1, Research and Development Annual Equity Fee Under the Founder’s Agreement with Checkpoint dated March 17, 2015 and amended in July 2016 and October 2017 (the “Founders Agreement”), Fortress is entitled to an annual equity fee on January 1 of each year equal to 2.5% of fully diluted outstanding equity, payable in Checkpoint common shares (“Annual Equity Fee”). The Annual Equity Fee was part of the consideration payable for formation of the Company, identification of certain assets, including the license contributed to Checkpoint by Fortress (see Note 4). The Company records the Annual Equity Fee in connection with the Founders Agreement with Fortress as contingent consideration. Contingent consideration is recorded when probable and reasonably estimable. The Company’s future share prices and shares outstanding cannot be estimated prior to the issuance of the Annual Equity Fee due to the nature of its assets and the Company’s stage of development. Due to these uncertainties, the Company has concluded that it is unable to reasonably estimate the contingent consideration until shares are actually issued on January 1 of each year. Pursuant to the Founders Agreement, the Company issued 1,459,305 shares of common stock to Fortress on June 4, 2020 for the Annual Equity Fee, representing 2.5% of the fully-diluted outstanding equity of Checkpoint on January 1, 2020. The Company did not have enough unreserved authorized shares under its Certificate of Incorporation on January 1, 2020 to issue the shares for the Annual Equity Fee, therefore, in December 2019, Fortress and Checkpoint mutually agreed to defer the issuance until such time as the Checkpoint Charter has been amended in order to increase the number of authorized shares that may be issued thereunder. At the Company's 2020 Annual Meeting of Stockholders held on June 4, 2020, its stockholders approved an amendment to its certificate of incorporation to increase the number of authorized shares of common stock available to issue. Because the number of outstanding shares issuable to Fortress was determinable on January 1, 2020 prior to the issuance of the December 31, 2019 financial statements, the Company recorded approximately $2.5 million in research and development expense and a credit to Common shares issuable - Founders Agreement during the year ended December 31, 2019. Pursuant to the Founders Agreement, the Company issued 1,742,449 shares of common stock to Fortress for the Annual Equity Fee, representing 2.5% of the fully-diluted outstanding equity of Checkpoint on January 1, 2021. Because the number of outstanding shares issuable to Fortress was determinable on January 1, 2021 prior to the issuance of the December 31, 2020 financial statements, the Company recorded approximately $4.6 million in research and development expense and a credit to Common shares issuable - Founders Agreement during the year ended December 31, 2020. Stock-Based Compensation Expenses The Company expenses stock-based compensation over the requisite service period based on the estimated grant-date fair value of the awards and forfeiture rates. The Company accounts for forfeitures as they occur. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. All stock-based compensation costs are recorded in general and administrative or research and development costs in the Statements of Operations based upon the underlying individual’s role at the Company. Fair Value Measurement The Company follows the accounting guidance in ASC 820 for its fair value measurements of financial assets and liabilities measured at fair value on a recurring basis. Under this accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance requires fair value measurements be classified and disclosed in one of the following three categories: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Certain of the Company's financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as accounts payable and accrued expenses. Revenue from Contracts with Customers The Company recognizes revenue under ASC 606, “Revenue from Contracts with Customers.” The core principle of the new revenue standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The following five steps are applied to achieve that core principle: ● Step 1: Identify the contract with the customer ● Step 2: Identify the performance obligations in the contract ● Step 3: Determine the transaction price ● Step 4: Allocate the transaction price to the performance obligations in the contract ● Step 5: Recognize revenue when the company satisfies a performance obligation In order to identify the performance obligations in a contract with a customer, a company must assess the promised goods or services in the contract and identify each promised good or service that is distinct. A performance obligation meets ASC 606’s definition of a “distinct” good or service (or bundle of goods or services) if both of the following criteria are met: ● The customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct). ● The entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract). If a good or service is not distinct, the good or service is combined with other promised goods or services until a bundle of goods or services is identified that is distinct. The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. When determining the transaction price, an entity must consider the effects of all of the following: ● Variable consideration ● Constraining estimates of variable consideration ● The existence of a significant financing component in the contract ● Noncash consideration ● Consideration payable to a customer Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The transaction price is allocated to each performance obligation on a relative standalone selling price basis. The transaction price allocated to each performance obligation is recognized when that performance obligation is satisfied, at a point in time or over time as appropriate. Revenue for a sales-based or usage-based royalty promised in exchange for a license of intellectual property is recognized only when (or as) the later of the following events occurs: a. The subsequent sale or usage occurs. b. The performance obligation to which some or all of the sales-based or usage-based royalty has been allocated has been satisfied (or partially satisfied). Incremental contract costs are expensed when incurred when the amortization period of the asset that would have been recognized is one year or less; otherwise, incremental contract costs are recognized as an asset and amortized over time as services are provided to a customer. Income Taxes The Company records income taxes using the asset and liability method. Deferred income tax assets and liabilities are recognized for the future tax effects attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases, and operating loss and tax credit carryforwards. The Company establishes a valuation allowance if management believes it is more likely than not that the deferred tax assets will not be recovered based on an evaluation of objective verifiable evidence. For tax positions that are more likely than not of being sustained upon audit, the Company recognizes the largest amount of the benefit that is greater than 50% likely of being realized. For tax positions that are not more likely than not of being sustained upon audit, the Company does not recognize any portion of the benefit. Net Loss per Share Net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding during the period. Since dividends are declared, paid and set aside among the holders of shares of common stock and Class A common stock pro-rata on an as-if-converted basis, the two-class method of computing net loss per share is not required. Diluted net loss per share does not reflect the effect of shares of common stock to be issued upon the exercise of stock options and warrants, as their inclusion would be anti-dilutive. The following table summarizes potentially dilutive securities outstanding at December 31, 2020 and 2019 that were excluded from the computation of diluted net loss per share, as they would be anti-dilutive: December 31, 2020 2019 Warrants (Note 6) 57,515 4,207,447 Stock options (Note 6) 220,000 160,000 Unvested restricted stock (Note 6) 3,869,896 3,303,839 Total 4,147,411 7,671,286 Coronavirus Aid, Relief and Economic Security Act ("CARES Act") In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act ("CARES Act") was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to refundable payroll tax credits, deferment of employer's social security payments, net operating loss utilization and carryback periods and modifications to the net interest deduction limitations. The CARES Act did not have a material impact on the Company’s income tax provision for 2020. The Company will continue to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. On December 27, 2020, the President of the United States signed the Consolidated Appropriations Act, 2021 (“Consolidated Appropriations Act”) into law. The Consolidated Appropriations Act is intended to enhance and expand certain provisions of the CARES Act, allows for the deductions of expenses related to the Payroll Protection Program funds received by companies, and provides an update to meals and entertainment expensing for 2021. The Consolidated Appropriations Act did not have a material impact to the Company’s income tax provision for 2020. Recently Issued Accounting Standards In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses” as amended by ASU 2019-10. The ASU sets forth a “current expected credit loss” (CECL) model which requires the Company to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions, and reasonable supportable forecasts. This replaces the existing incurred loss model and is applicable to the measurement of credit losses on financial assets measured at amortized cost and applies to some off-balance sheet credit exposures. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. In November 2019, the FASB issued ASU 2019-10, “Financial Instruments - Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) Effective Dates”, which deferred the effective dates for the Company, as a smaller reporting company, until fiscal year 2023. The Company is currently assessing the impact of the adoption of this ASU on its financial statements. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. The Company adopted the new guidance in the first quarter of 2021 and the adoption of this guidance did not to have a material impact on the financial statements. In August 2020, the FASB issued ASU No. 2020-06, “Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity”, which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. The ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and it also simplifies the diluted earnings per share calculation in certain areas. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption will be permitted. The Company is currently evaluating the impact of this standard on its financial statements. Recently Adopted Accounting Standards In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820), - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement,” which makes a number of changes meant to add, modify or remove certain disclosure requirements associated with the movement amongst or hierarchy associated with Level 1, Level 2 and Level 3 fair value measurements. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted upon issuance of the update. The Company adopted ASU No. 2018-13 as of January 1, 2020. The adoption of this update did not have a material impact on the Company’s financial statements.

License Agreements

License Agreements	12 Months Ended
License Agreements	Dec. 31, 2020
License Agreements
License Agreements	Note 3 - License Agreements Dana-Farber Cancer Institute In March 2015, the Company entered into an exclusive license agreement with Dana-Farber Cancer Institute (“Dana Farber”) to develop a portfolio of fully human immuno-oncology targeted antibodies. Under the terms of the license agreement, the Company paid Dana-Farber an up-front licensing fee of $1.0 million and, on May 11, 2015, granted Dana-Farber 500,000 shares, valued at $32,500 or $0.065 per share. The license agreement included an anti-dilution clause that maintained Dana-Farber’s ownership at 5% until such time that the Company raised $10 million in cash in exchange for common shares. Pursuant to this provision, on September 30, 2015, the Company granted to Dana-Farber an additional 136,830 shares of common stock valued at approximately $0.6 million and the anti-dilution clause thereafter expired. Dana-Farber is eligible to receive payments of up to an aggregate of approximately $21.5 million for each licensed product upon the Company’s successful achievement of certain clinical development, regulatory and first commercial sale milestones. In addition, Dana-Farber is eligible to receive up to an aggregate of $60.0 million upon the Company’s successful achievement of certain sales milestones based on aggregate net sales, in addition to royalty payments based on a tiered low to mid-single digit percentage of net sales. Dana-Farber also receives an annual license maintenance fee of $50,000, which is creditable against future milestone payments or royalties. The portfolio of antibodies licensed from Dana-Farber include antibodies targeting PD-L1, GITR and CAIX. In connection with the license agreement with Dana-Farber, the Company entered into a collaboration agreement with TGTX, which was amended and restated in June 2019, to develop and commercialize the anti-PD-L1 and anti-GITR antibody research programs in the field of hematological malignancies, while the Company retains the right to develop and commercialize these antibodies in solid tumors. Michael Weiss, Chairman of the Board of Directors of Checkpoint and Fortress’ Executive Vice Chairman, Strategic Development, is also the Executive Chairman, President and Chief Executive Officer and a stockholder of TGTX. Under the terms of the original collaboration agreement, TGTX paid the Company $0.5 million, representing an upfront licensing fee. Upon the signing of the amended and restated collaboration agreement in June 2019, TGTX paid the Company an additional $1.0 million upfront licensing fee. The Company is eligible to receive substantive potential milestone payments for the anti-PD-L1 program of up to an aggregate of approximately $27.6 million upon TGTX’s successful achievement of certain clinical development, regulatory and first commercial sale milestones. This is comprised of up to approximately $8.4 million upon TGTX’s successful completion of clinical development milestones, and up to approximately $19.2 million upon regulatory filings and first commercial sales in specified territories. The Company is also eligible to receive substantive potential milestone payments for the anti-GITR antibody program of up to an aggregate of approximately $21.5 million upon TGTX's successful achievement of certain clinical development, regulatory and first commercial sale milestones. This is comprised of up to approximately $7.0 million upon TGTX's successful completion of clinical development milestones, and up to approximately $14.5 million upon first commercial sales in specified territories. In addition, the Company is eligible to receive up to an aggregate of $60.0 million upon TGTX’s successful achievement of certain sales milestones based on aggregate net sales for both programs, in addition to royalty payments based on a tiered low double-digit percentage of net sales. The Company also receives an annual license maintenance fee, which is creditable against future milestone payments or royalties. TGTX also pays the Company for its out-of-pocket costs of material used by TGTX for their development activities. For the years ended December 31, 2020 and 2019, the Company recognized approximately $1.0 million and $1.6 million, respectively, in revenue related to the collaboration agreement in the Statements of Operations. The revenue for the year ended December 31, 2020 included a milestone of $925,000 upon the 12th patient dosed in a phase 1 clinical trial for the anti-PD-L1 antibody cosibelimab during March 2020. Adimab, LLC In October 2015, Fortress entered into a collaboration agreement with Adimab, LLC (“Adimab”) to discover and optimize antibodies using their proprietary core technology platform. Under this agreement, Adimab optimized cosibelimab (formerly referred to as CK-301), the Company’s anti-PD-L1 antibody which it originally licensed from Dana-Farber. In January 2019, Fortress transferred the rights to the optimized antibody to the Company, and Checkpoint entered into a collaboration agreement directly with Adimab on the same day. Under the terms of the agreement, Adimab is eligible to receive payments up to an aggregate of approximately $7.1 million upon the Company’s successful achievement of certain clinical development and regulatory milestones, of which $4.8 million are due upon various filings for regulatory approvals to commercialize the product. In addition, Adimab is eligible to receive royalty payments based on a tiered low single digit percentage of net sales. NeuPharma, Inc. In March 2015, Fortress entered into an exclusive license agreement with NeuPharma, Inc. ("NeuPharma") to develop and commercialize novel irreversible, 3rd generation EGFR inhibitors, including CK-101, on a worldwide basis other than certain Asian countries. On the same date, Fortress assigned all of its right and interest in the EGFR inhibitors to the Company. Under the terms of the license agreement, the Company paid NeuPharma an up-front licensing fee of $1.0 million, and NeuPharma is eligible to receive payments of up to an aggregate of approximately $40.0 million upon the Company’s successful achievement of certain clinical development and regulatory milestones in up to three indications, of which $22.5 million are due upon various regulatory approvals to commercialize the products. In addition, NeuPharma is eligible to receive payments of up to an aggregate of $40.0 million upon the Company’s successful achievement of certain sales milestones based on aggregate net sales, in addition to royalty payments based on a tiered mid to high-single digit percentage of net sales. Jubilant Biosys Limited In May 2016, the Company entered into a license agreement with Jubilant Biosys Limited (“Jubilant”), whereby the Company obtained an exclusive, worldwide license to Jubilant’s family of patents covering compounds that inhibit BET proteins such as BRD4, including CK-103. Under the terms of the license agreement, the Company paid Jubilant an up-front licensing fee of $2.0 million, and Jubilant is eligible to receive payments up to an aggregate of approximately $89.0 million upon the Company’s successful achievement of certain clinical development and regulatory milestones, of which $59.5 million are due upon various regulatory approvals to commercialize the products. In addition, Jubilant is eligible to receive payments up to an aggregate of $89.0 million upon the Company’s successful achievement of certain sales milestones based on aggregate net sales, in addition to royalty payments based on a tiered low to mid-single digit percentage of net sales. In connection with the license agreement with Jubilant, the Company entered into a sublicense agreement with TGTX, a related party, to develop and commercialize the compounds licensed in the field of hematological malignancies, while the Company retains the right to develop and commercialize these compounds in the field of solid tumors. Under the terms of the sublicense agreement, TGTX paid the Company $1.0 million, representing an upfront licensing fee, and the Company is eligible to receive substantive potential milestone payments up to an aggregate of approximately $87.2 million upon TGTX’s successful achievement of clinical development and regulatory milestones. This is comprised of up to approximately $25.5 million upon TGTX’s successful completion of three clinical development milestones for two licensed products, and up to approximately $61.7 million upon the achievement of five regulatory approvals and first commercial sales in specified territories for two licensed products. In addition, the Company is eligible to receive potential milestone payments up to an aggregate of $89.0 million upon TGTX’s successful achievement of certain sales milestones based on aggregate net sales by TGTX, for two licensed products, in addition to royalty payments based on a mid-single digit percentage of net sales by TGTX. TGTX also pays the Company 50% of IND enabling costs and patent expenses. For each of the years ended December 31, 2020 and 2019, the Company recognized approximately $0.1 million in revenue related to the sublicense agreement in the Statements of Operations. The collaborations with TGTX each contain single material performance obligations under Topic 606, which is the granting of a license that is functional intellectual property. The Company’s performance obligation was satisfied at the point in time when TGTX had the ability to use and benefit from the right to use the intellectual property. The performance obligations of the original agreements were satisfied prior to the adoption of Topic 606. The performance obligation of the amendment to the collaboration agreement was satisfied in June 2019. The milestone payments are based on successful achievement of clinical development, regulatory, and sales milestones. Because these payments are contingent on the occurrence of a future event, they represent variable consideration and are constrained and included in the transaction price only when it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. The sales-based royalty payments are recognized as revenue when the subsequent sales occur. The Company also receives variable consideration for certain research and development, out-of-pocket material costs and patent maintenance related activities that are dependent upon the Company’s actual expenditures under the collaborations and are constrained and included in the transaction price only when it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. Revenue is recognized approximately when the amounts become due because it relates to an already satisfied performance obligation. For the year ended December 31, 2020, the Company recognized the achievement of a clinical development milestone under its collaboration agreement with TGTX based upon their dosing of a 12th patient in a phase 1 clinical trial of cosibelimab (see “Dana-Farber Cancer Institute” earlier in this Note for more information).

Related Party Agreements

Related Party Agreements	12 Months Ended
Related Party Agreements	Dec. 31, 2020
Related Party Agreements
Related Party Agreements	Note 4 - Related Party Agreements Founders Agreement and Management Services Agreement with Fortress Effective March 17, 2015, the Company entered into a Founders Agreement with Fortress, which was amended in July 2016 and October 2017. The Founders Agreement provides, that in exchange for the time and capital expended in the formation of Checkpoint and the identification of specific assets the acquisition of which resulted in the formation of a viable emerging growth life science company, the Company assumed $2.8 million in debt that Fortress accumulated under a promissory note through National Securities Corporation for expenses and costs of forming Checkpoint, and the Company shall also: (i) issue annually to Fortress, on January 1 of each year, shares of common stock equal to two and one-half percent (2.5%) of the fully-diluted outstanding equity of Checkpoint at the time of issuance; (ii) pay an equity fee in shares of common stock, payable within five (5) business days of the closing of any equity or debt financing for Checkpoint or any of its respective subsidiaries that occurs after the effective date of the Founders Agreement and ending on the date when Fortress no longer has majority voting control in Checkpoint’s voting equity, equal to two and one-half percent (2.5%) of the gross amount of any such equity or debt financing; and (iii) pay a cash fee equal to four and one half percent (4.5%) of Checkpoint’s annual net sales, payable on an annual basis, within ninety (90) days of the end of each calendar year. In the event of a change in control (as it is defined in the Founders Agreement), Checkpoint will pay a one-time change in control fee equal to five times (5x) the product of (i) monthly net sales for the twelve (12) months immediately preceding the change in control and (ii) four and one-half percent (4.5%). The Founders Agreement has a term of fifteen years, after which it automatically renews for one-year periods unless Fortress gives the Company notice of termination. The Founders Agreement will also automatically terminate upon a change of control. Effective March 17, 2015, the Company entered into a Management Services Agreement (the “MSA”) with Fortress. Pursuant to the terms of the MSA, for a period of five (5) years, Fortress will render advisory and consulting services to the Company. Services provided under the MSA may include, without limitation, (i) advice and assistance concerning any and all aspects of Checkpoint’s operations, clinical trials, financial planning and strategic transactions and financings and (ii) conducting relations on behalf of the Company with accountants, attorneys, financial advisors and other professionals (collectively, the “Services”). The Company is obligated to utilize clinical research services, medical education, communication and marketing services and investor relations/public relation services of companies or individuals designated by Fortress, provided those services are offered at market prices. However, the Company is not obligated to take or act upon any advice rendered from Fortress and Fortress shall not be liable for any of the Company’s actions or inactions based upon their advice. Fortress and its affiliates, including all members of its Board of Directors, have been contractually exempt from fiduciary duties to the Company relating to corporate opportunities. In consideration for the Services, the Company will pay Fortress an annual consulting fee of $0.5 million (the “Annual Consulting Fee”), payable in advance in equal quarterly installments on the first business day of each calendar quarter in each year, provided, however, that such Annual Consulting Fee shall be increased to $1.0 million for each calendar year in which the Company has net assets in excess of $100 million at the beginning of the calendar year. For the years ended December 31, 2020 and 2019, the Company recognized $0.5 million in expense on its Statements of Operations related to the MSA. Caribe BioAdvisors, LLC In December 2016, the Company entered into an advisory agreement effective January 1, 2017 with Caribe BioAdvisors, LLC (“Caribe”), owned by Michael Weiss, to provide the advisory services of Mr. Weiss as Chairman of the Board. Pursuant to the agreement, Caribe will be paid an annual cash fee of $60,000, in addition to any and all annual equity incentive grants paid to members of the board. For the years ended December 31, 2020 and 2019, the Company recognized $111,000 and $104,000, respectively, in expense in its Statements of Operations related to the advisory agreement, including $51,000 and $44,000, respectively, in expense related to annual equity incentive grants.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2020
Commitments and Contingencies
Commitments and Contingencies	Note 5 - Commitments and Contingencies Leases The Company is not a party to any leases for office space or equipment. License Agreements The Company has undertaken to make contingent milestone payments to the licensors of its portfolio of product candidates. In addition, the Company would pay royalties to such licensors based on a percentage of net sales of each product candidate following regulatory marketing approval (See Note 3). Litigation The Company recognizes a liability for a contingency when it is probable that liability has been incurred and when the amount of loss can be reasonably estimated. When a range of probable loss can be estimated, the Company accrues the most likely amount of such loss, and if such amount is not determinable, then the Company accrues the minimum of the range of probable loss. As of December 31, 2020 and 2019, there was no litigation against the Company.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2020
Stockholders' Equity
Stockholders' Equity	Note 6 - Stockholders’ Equity Common Stock At the Company's 2020 Annual Meeting of Stockholders held on June 4, 2020, its stockholders approved an amendment to its certificate of incorporation to increase the number of authorized shares of common stock available to issue by 35,000,000 to 95,000,000 with a par value of $0.0001 per share, of which 7,000,000 shares are designated as “Class A common stock.” The amendment was filed with the Secretary of State of the State of Delaware on June 4, 2020. As of December 31, 2020 and 2019, there were 7,000,000 shares of Class A common stock issued and outstanding In November 2017, the Company filed a shelf registration statement on Form S-3 (the "2017 S-3"), which was declared effective in December 2017. Under the 2017 S-3, the Company may sell up to a total of $100 million of its securities. In connection with the 2017 S-3, the Company entered into an ATM (the "2017 ATM") with Cantor Fitzgerald & Co., Ladenburg Thalmann & Co. Inc. and H.C. Wainwright & Co., LLC (each an "Agent" and collectively, the "Agents"), relating to the sale of shares of common stock. Under the ATM, the Company pays the Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of common stock. In November 2019, the Company completed an underwritten public offering, in which it sold 15,400,000 shares of its common stock at a price of $1.27 per share for gross proceeds of approximately $19.6 million. Total net proceeds from the offering were approximately $17.6 million, net of underwriting discounts and offering expenses of approximately $2.0 million. During the year ended December 31, 2019, the Company sold a total of 2,273,189 shares of common stock under the ATM for aggregate total gross proceeds of approximately $8.0 million at an average selling price of $3.52 per share, resulting in net proceeds of approximately $7.8 million after deducting commissions and other transactions costs. In September 2020, the Company completed an underwritten public offering in which it sold 7,321,429 shares of its common stock at a price of $2.80 per share for gross proceeds of approximately $20.5 million. Total net proceeds from the offering were approximately $18.9 million, net of underwriting discounts and offering expenses of approximately $1.6 million. During the year ended December 31, 2020, the Company sold a total of 5,104,234 shares of common stock under an At-the-Market Issuance Sales Agreement for aggregate total gross proceeds of approximately $12.8 million at an average selling price of $2.50 per share, resulting in net proceeds of approximately $12.4 million after deducting commissions and other transaction costs. Pursuant to the Founders Agreement, the Company issued to Fortress 2.5% of the aggregate number of shares of common stock issued in the offerings noted above. Accordingly, the Company issued 310,625 shares and 441,816 shares to Fortress for the year ended December 31, 2020 and 2019, respectively, and recorded expenses of approximately $901,000 and $738,000 related to these stock grants, which is included in general and administrative expenses in the Company’s Statements of Operations for the years ended December 31, 2020 and 2019, respectively. Pursuant to the Founders Agreement, the Company issued 1,459,305 shares of common stock to Fortress on June 4, 2020 for the Annual Equity Fee, representing 2.5% of the fully-diluted outstanding equity of Checkpoint on January 1, 2020. The Company did not have enough unreserved authorized shares under its Certificate of Incorporation on January 1, 2020 to issue the shares for the Annual Equity Fee, therefore, in December 2019, Fortress and Checkpoint mutually agreed to defer the issuance until such time as the Checkpoint Charter has been amended in order to increase the number of authorized shares that may be issued thereunder. Pursuant to the Founders Agreement, the Company issued 1,742,449 shares of common stock to Fortress for the Annual Equity Fee, representing 2.5% of the fully-diluted outstanding equity of Checkpoint on January 1, 2021 (see Notes 2 and 4). In November 2020, the Company filed a shelf registration statement on Form S-3 (the “2020 S-3”), which was declared effective in December 2020. Under the S-3, the Company may sell up to a total of $100 million of its securities. In connection with the S-3, the Company entered into an ATM (the “2020 ATM”) with the Agents relating to the sale of shares of common stock. Under the 2020 ATM, the Company pays the Agents a commission rate of up to 3.0% of the gross proceeds from the sale of any shares of common stock. Subsequent to the fourth quarter, through March 5, 2021, the Company sold a total of 3,170,216 shares of common stock under the 2020 ATM for aggregate total gross proceeds of approximately $12.3 million at an average selling price of $3.88 per share, resulting in net proceeds of approximately $12.0 million after deducting commissions and other transaction costs. Subsequent to the offerings noted above, approximately $83.6 million of securities remain available for sale under the 2020 S-3. The Company may offer the securities under the 2020 S-3 from time to time in response to market conditions or other circumstances if it believes such a plan of financing is in the best interests of its stockholders. Equity Incentive Plan The Company has in effect the Amended and Restated 2015 Incentive Plan (“2015 Incentive Plan”). The 2015 Incentive Plan was adopted in March 2015 by our stockholders. Under the 2015 Incentive Plan, the compensation committee of the Company’s board of directors is authorized to grant stock-based awards to directors, officers, employees and consultants. An amendment to the 2015 Incentive Plan was approved by stockholders in June 2020 to increase the shares available for issuance to 9,000,000 shares. The plan expires 10 years from the effective date of the amendment and limits the term of each option to no more than 10 years from the date of grant. As of December 31, 2020, 4,288,465 shares are available for issuance under the 2015 Incentive Plan. Restricted Stock Certain employees, directors and consultants have been awarded restricted stock. The restricted stock vesting consists of milestone and time-based vesting. The following table summarizes restricted stock award activity for the year ended December 31, 2020 and 2019: Weighted Average Grant Date Fair Number of Shares Value Nonvested at December 31, 2018 2,932,106 $ 4.22 Granted 800,652 3.33 Forfeited (21,000) 3.16 Vested (407,919) 1.96 Nonvested at December 31, 2019 3,303,839 $ 4.29 Granted 1,117,340 2.39 Vested (551,283) 5.23 Non-vested at December 31, 2020 3,869,896 $ 3.61 As of December 31, 2020, there was $2.8 million of total unrecognized compensation cost related to non-vested restricted stock, which is expected to be recognized over a weighted-average period of 1.9 years. This amount does not include, as of December 31, 2020, 333,334 shares of restricted stock outstanding which are performance-based and vest upon achievement of certain corporate milestones. The expense is recognized over the vesting period of the award. Stock-based compensation for milestone awards will be measured and recorded if and when it is probable that the milestone will be achieved. Stock Options The following table summarizes stock option award activity for the year ended December 31, 2020 and 2019: Weighted Average Remaining Weighted Average Contractual Life Stock Options Exercise Price (in years) Outstanding as of December 31, 2018 60,000 $ 5.43 8.09 Granted 100,000 2.56 Outstanding as of December 31, 2019 160,000 $ 3.64 8.56 Granted 60,000 2.04 Outstanding as of December 31, 2020 220,000 $ 3.20 8.04 Vested and exercisable as of December 31, 2020 25,000 $ 1.87 8.82 Upon the exercise of stock options, the Company will issue new shares of its common stock. The Company used the Black-Scholes option pricing model for determining the estimated fair value of stock-based compensation related to stock options. The table below summarizes the assumptions used: For the Years Ended December 31, 2020 2019 Risk-free interest rate 0.65% - 1.02% 1.77% - 2.72% Expected dividend yield — — Expected term in years 10.0 10.0 Expected volatility 101.27% - 104.60% 99.84% - 103.79% Warrants A summary of warrant activities for year ended December 31, 2020 and 2019 is presented below: Weighted Average Remaining Weighted Average Contractual Life Warrants Exercise Price (in years) Outstanding as of December 31, 2018 4,280,972 $ 6.69 2.33 Exercised (73,525) — Outstanding as of December 31, 2019 4,207,447 $ 6.81 1.25 Exercised (102,742) 0.13 Expired (4,047,190) 7.00 Outstanding as of December 31, 2020 57,515 $ 5.39 1.22 Upon the exercise of warrants, the Company will issue new shares of its common stock. Stock-Based Compensation The following table summarizes stock-based compensation expense for the years ended December 31, 2020 and 2019 (in thousands). For the year ended December 31, 2020 2019 Research and development $ 617 $ 707 General and administrative 2,163 2,414 Total stock-based compensation expense $ 2,780 $ 3,121

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2020
Income Taxes
Income Taxes	Note 7 - Income Taxes The Company has accumulated net losses since inception and has not recorded an income tax provision or benefit during the years ended December 31, 2020 and 2019. A reconciliation of the statutory U.S. federal rate to the Company’s effective tax rate is as follows: For the Year Ended December 31, 2020 2019 Percentage of pre-tax income: Statutory federal income tax rate 21 % 21 % State taxes, net of federal tax benefit 5 % 6 % Change in state tax rate (1) % 2 % Provision to return 1 % — % Stock based compensation shortfall (1) % (1) % Other (1) % (1) % Change in valuation allowance (24) % (27) % Income taxes provision (benefit) — % — % The components of the net deferred tax asset as of December 31, 2020 and 2019 are the following (in thousands): As of December 31, 2020 2019 Deferred tax assets: Net operating loss carryovers $ 27,537 $ 23,051 Stock compensation and other 2,191 2,057 Amortization of license 5,560 4,878 Accruals and reserves 178 184 Tax credits 1,781 1,532 Start Up Costs 28 31 Total deferred tax assets 37,275 31,733 Less valuation allowance (37,275) (31,733) Deferred tax asset, net of valuation allowance $ — $ — The Company has determined, based upon available evidence, that it is more likely than not that the net deferred tax asset will not be realized and, accordingly, has provided a full valuation allowance against its net deferred tax asset. A valuation allowance of approximately $37.3 million and $31.7 million was recorded for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, the Company had federal and state net operating loss carryforwards of approximately $101.1 million and $94.9 million, respectively. Approximately $69.9 million of the federal net operating loss carryforwards can be carried forward indefinitely. The remaining $31.2 million of federal and all state net operating loss carryforwards will begin to expire, if not utilized, by 2035 and 2035, respectively. The Company has $1.1 million of research and development credit carryforwards and $0.7 million of orphan drug credit carryforwards, which will begin to expire, if not utilized, by 2035 There are no significant matters determined to be unrecognized tax benefits taken or expected to be taken in a tax return, in accordance with ASC 740 “Income Taxes” (“ASC 740”), which clarifies the accounting for uncertainty in income taxes recognized in the financial statements, that have been recorded on the Company’s financial statements for the year ended December 31, 2020 and 2019. The Company does not anticipate a material change to unrecognized tax benefits in the next twelve months. Additionally, ASC 740 provides guidance on the recognition of interest and penalties related to income taxes. There were no interest or penalties related to income taxes that have been accrued or recognized as of and for the period ended December 31, 2020 and 2019. The Company would classify interest and penalties related to uncertain tax positions as income tax expense, if applicable. The federal and state tax returns for the periods ended December 31, 2017, 2018 and 2019 are currently open for examination under the applicable federal and state income tax statues of limitations. The Company is currently under examination by the New York City Department Finance for the 2016, 2017 and 2018 tax years. While the outcomes of the examinations are unknown, the Company does not expect any material adjustments.

Accounts Payable and Accrued Ex

Accounts Payable and Accrued Expenses	12 Months Ended
Accounts Payable and Accrued Expenses	Dec. 31, 2020
Accounts Payable and Accrued Expenses
Accounts Payable and Accrued Expenses	Note 8 - Accounts Payable and Accrued Expenses At December 31, 2020 and 2019, accounts payable and accrued expenses consisted of the following (in thousands): December 31, 2020 2019 Accounts payable $ 3,438 $ 3,079 Accrued compensation 535 414 Research and development 2,009 3,496 Other 385 268 Total accounts payable and accrued expenses $ 6,367 $ 7,257

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2020
Significant Accounting Policies
Basis of Presentation	Basis of Presentation The Company’s financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include all adjustments necessary for the fair presentation of the Company’s financial position for the periods presented. The Company has no subsidiaries.
Segments	Segments Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company views its operations and manages its business in one operating and reporting segment.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents.
Other Receivables - Related Party	Other Receivables - Related Party Other receivables includes amounts due to the Company from TG Therapeutics, Inc. (“TGTX”), a related party, and are recorded at the invoiced amount.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Upfront and milestone payments due to third parties that perform research and development services on the Company’s behalf will be expensed as services are rendered or when the milestone is achieved. Research and development costs primarily consist of personnel related expenses, including salaries, benefits, travel, and other related expenses, stock-based compensation, payments made to third parties for license and milestone costs related to in-licensed products and technology, payments made to third party contract research organizations for preclinical and clinical studies, investigative sites for clinical trials, consultants, the cost of acquiring and manufacturing clinical trial materials, costs associated with regulatory filings, laboratory costs and other supplies. In accordance with Accounting Standards Codification (“ASC”) 730-10-25-1, Research and Development
Annual Equity Fee	Annual Equity Fee Under the Founder’s Agreement with Checkpoint dated March 17, 2015 and amended in July 2016 and October 2017 (the “Founders Agreement”), Fortress is entitled to an annual equity fee on January 1 of each year equal to 2.5% of fully diluted outstanding equity, payable in Checkpoint common shares (“Annual Equity Fee”). The Annual Equity Fee was part of the consideration payable for formation of the Company, identification of certain assets, including the license contributed to Checkpoint by Fortress (see Note 4). The Company records the Annual Equity Fee in connection with the Founders Agreement with Fortress as contingent consideration. Contingent consideration is recorded when probable and reasonably estimable. The Company’s future share prices and shares outstanding cannot be estimated prior to the issuance of the Annual Equity Fee due to the nature of its assets and the Company’s stage of development. Due to these uncertainties, the Company has concluded that it is unable to reasonably estimate the contingent consideration until shares are actually issued on January 1 of each year. Pursuant to the Founders Agreement, the Company issued 1,459,305 shares of common stock to Fortress on June 4, 2020 for the Annual Equity Fee, representing 2.5% of the fully-diluted outstanding equity of Checkpoint on January 1, 2020. The Company did not have enough unreserved authorized shares under its Certificate of Incorporation on January 1, 2020 to issue the shares for the Annual Equity Fee, therefore, in December 2019, Fortress and Checkpoint mutually agreed to defer the issuance until such time as the Checkpoint Charter has been amended in order to increase the number of authorized shares that may be issued thereunder. At the Company's 2020 Annual Meeting of Stockholders held on June 4, 2020, its stockholders approved an amendment to its certificate of incorporation to increase the number of authorized shares of common stock available to issue. Because the number of outstanding shares issuable to Fortress was determinable on January 1, 2020 prior to the issuance of the December 31, 2019 financial statements, the Company recorded approximately $2.5 million in research and development expense and a credit to Common shares issuable - Founders Agreement during the year ended December 31, 2019. Pursuant to the Founders Agreement, the Company issued 1,742,449 shares of common stock to Fortress for the Annual Equity Fee, representing 2.5% of the fully-diluted outstanding equity of Checkpoint on January 1, 2021. Because the number of outstanding shares issuable to Fortress was determinable on January 1, 2021 prior to the issuance of the December 31, 2020 financial statements, the Company recorded approximately $4.6 million in research and development expense and a credit to Common shares issuable - Founders Agreement during the year ended December 31, 2020.
Stock-Based Compensation Expenses	Stock-Based Compensation Expenses The Company expenses stock-based compensation over the requisite service period based on the estimated grant-date fair value of the awards and forfeiture rates. The Company accounts for forfeitures as they occur. The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model. The assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment. All stock-based compensation costs are recorded in general and administrative or research and development costs in the Statements of Operations based upon the underlying individual’s role at the Company.
Fair Value Measurement	Fair Value Measurement The Company follows the accounting guidance in ASC 820 for its fair value measurements of financial assets and liabilities measured at fair value on a recurring basis. Under this accounting guidance, fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability. The accounting guidance requires fair value measurements be classified and disclosed in one of the following three categories: Level 1: Quoted prices in active markets for identical assets or liabilities. Level 2: Observable inputs other than Level 1 prices, for similar assets or liabilities that are directly or indirectly observable in the marketplace. Level 3: Unobservable inputs which are supported by little or no market activity and that are financial instruments whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant judgment or estimation. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Certain of the Company's financial instruments are not measured at fair value on a recurring basis but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as accounts payable and accrued expenses.
Revenue from Contracts with Customers	Revenue from Contracts with Customers The Company recognizes revenue under ASC 606, “Revenue from Contracts with Customers.” The core principle of the new revenue standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The following five steps are applied to achieve that core principle: ● Step 1: Identify the contract with the customer ● Step 2: Identify the performance obligations in the contract ● Step 3: Determine the transaction price ● Step 4: Allocate the transaction price to the performance obligations in the contract ● Step 5: Recognize revenue when the company satisfies a performance obligation In order to identify the performance obligations in a contract with a customer, a company must assess the promised goods or services in the contract and identify each promised good or service that is distinct. A performance obligation meets ASC 606’s definition of a “distinct” good or service (or bundle of goods or services) if both of the following criteria are met: ● The customer can benefit from the good or service either on its own or together with other resources that are readily available to the customer (i.e., the good or service is capable of being distinct). ● The entity’s promise to transfer the good or service to the customer is separately identifiable from other promises in the contract (i.e., the promise to transfer the good or service is distinct within the context of the contract). If a good or service is not distinct, the good or service is combined with other promised goods or services until a bundle of goods or services is identified that is distinct. The transaction price is the amount of consideration to which an entity expects to be entitled in exchange for transferring promised goods or services to a customer, excluding amounts collected on behalf of third parties (for example, some sales taxes). The consideration promised in a contract with a customer may include fixed amounts, variable amounts, or both. When determining the transaction price, an entity must consider the effects of all of the following: ● Variable consideration ● Constraining estimates of variable consideration ● The existence of a significant financing component in the contract ● Noncash consideration ● Consideration payable to a customer Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. The transaction price is allocated to each performance obligation on a relative standalone selling price basis. The transaction price allocated to each performance obligation is recognized when that performance obligation is satisfied, at a point in time or over time as appropriate. Revenue for a sales-based or usage-based royalty promised in exchange for a license of intellectual property is recognized only when (or as) the later of the following events occurs: a. The subsequent sale or usage occurs. b. The performance obligation to which some or all of the sales-based or usage-based royalty has been allocated has been satisfied (or partially satisfied). Incremental contract costs are expensed when incurred when the amortization period of the asset that would have been recognized is one year or less; otherwise, incremental contract costs are recognized as an asset and amortized over time as services are provided to a customer.
Income Taxes	Income Taxes The Company records income taxes using the asset and liability method. Deferred income tax assets and liabilities are recognized for the future tax effects attributable to temporary differences between the financial statement carrying amounts of existing assets and liabilities and their respective income tax bases, and operating loss and tax credit carryforwards. The Company establishes a valuation allowance if management believes it is more likely than not that the deferred tax assets will not be recovered based on an evaluation of objective verifiable evidence. For tax positions that are more likely than not of being sustained upon audit, the Company recognizes the largest amount of the benefit that is greater than 50% likely of being realized. For tax positions that are not more likely than not of being sustained upon audit, the Company does not recognize any portion of the benefit.
Net Loss per Share	Net Loss per Share Net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding during the period. Since dividends are declared, paid and set aside among the holders of shares of common stock and Class A common stock pro-rata on an as-if-converted basis, the two-class method of computing net loss per share is not required. Diluted net loss per share does not reflect the effect of shares of common stock to be issued upon the exercise of stock options and warrants, as their inclusion would be anti-dilutive. The following table summarizes potentially dilutive securities outstanding at December 31, 2020 and 2019 that were excluded from the computation of diluted net loss per share, as they would be anti-dilutive: December 31, 2020 2019 Warrants (Note 6) 57,515 4,207,447 Stock options (Note 6) 220,000 160,000 Unvested restricted stock (Note 6) 3,869,896 3,303,839 Total 4,147,411 7,671,286
Coronavirus Aid, Relief and Economic Security Act ("CARES Act")	Coronavirus Aid, Relief and Economic Security Act ("CARES Act") In response to the COVID-19 pandemic, the Coronavirus Aid, Relief and Economic Security Act ("CARES Act") was signed into law on March 27, 2020. The CARES Act, among other things, includes tax provisions relating to refundable payroll tax credits, deferment of employer's social security payments, net operating loss utilization and carryback periods and modifications to the net interest deduction limitations. The CARES Act did not have a material impact on the Company’s income tax provision for 2020. The Company will continue to evaluate the impact of the CARES Act on its financial position, results of operations and cash flows. On December 27, 2020, the President of the United States signed the Consolidated Appropriations Act, 2021 (“Consolidated Appropriations Act”) into law. The Consolidated Appropriations Act is intended to enhance and expand certain provisions of the CARES Act, allows for the deductions of expenses related to the Payroll Protection Program funds received by companies, and provides an update to meals and entertainment expensing for 2021. The Consolidated Appropriations Act did not have a material impact to the Company’s income tax provision for 2020.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses” as amended by ASU 2019-10. The ASU sets forth a “current expected credit loss” (CECL) model which requires the Company to measure all expected credit losses for financial instruments held at the reporting date based on historical experience, current conditions, and reasonable supportable forecasts. This replaces the existing incurred loss model and is applicable to the measurement of credit losses on financial assets measured at amortized cost and applies to some off-balance sheet credit exposures. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted. In November 2019, the FASB issued ASU 2019-10, “Financial Instruments - Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) Effective Dates”, which deferred the effective dates for the Company, as a smaller reporting company, until fiscal year 2023. The Company is currently assessing the impact of the adoption of this ASU on its financial statements. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes” (“ASU 2019-12”), which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020, with early adoption permitted. The Company adopted the new guidance in the first quarter of 2021 and the adoption of this guidance did not to have a material impact on the financial statements. In August 2020, the FASB issued ASU No. 2020-06, “Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging-Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity”, which simplifies accounting for convertible instruments by removing major separation models required under current GAAP. The ASU removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception and it also simplifies the diluted earnings per share calculation in certain areas. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption will be permitted. The Company is currently evaluating the impact of this standard on its financial statements. Recently Adopted Accounting Standards In August 2018, the FASB issued ASU 2018-13, “Fair Value Measurement (Topic 820), - Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement,” which makes a number of changes meant to add, modify or remove certain disclosure requirements associated with the movement amongst or hierarchy associated with Level 1, Level 2 and Level 3 fair value measurements. This guidance is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted upon issuance of the update. The Company adopted ASU No. 2018-13 as of January 1, 2020. The adoption of this update did not have a material impact on the Company’s financial statements.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
Significant Accounting Policies (Tables)	Dec. 31, 2020
Significant Accounting Policies
Schedule of potentially dilutive securities outstanding, that were excluded from the computation of diluted net loss per share, as they would be anti-dilutive	December 31, 2020 2019 Warrants (Note 6) 57,515 4,207,447 Stock options (Note 6) 220,000 160,000 Unvested restricted stock (Note 6) 3,869,896 3,303,839 Total 4,147,411 7,671,286

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
Stockholders' Equity (Tables)	Dec. 31, 2020
Stockholders' Equity
Summary of restricted stock award activity	Certain employees, directors and consultants have been awarded restricted stock. The restricted stock vesting consists of milestone and time-based vesting. The following table summarizes restricted stock award activity for the year ended December 31, 2020 and 2019: Weighted Average Grant Date Fair Number of Shares Value Nonvested at December 31, 2018 2,932,106 $ 4.22 Granted 800,652 3.33 Forfeited (21,000) 3.16 Vested (407,919) 1.96 Nonvested at December 31, 2019 3,303,839 $ 4.29 Granted 1,117,340 2.39 Vested (551,283) 5.23 Non-vested at December 31, 2020 3,869,896 $ 3.61
Summary of stock option award activity	The following table summarizes stock option award activity for the year ended December 31, 2020 and 2019: Weighted Average Remaining Weighted Average Contractual Life Stock Options Exercise Price (in years) Outstanding as of December 31, 2018 60,000 $ 5.43 8.09 Granted 100,000 2.56 Outstanding as of December 31, 2019 160,000 $ 3.64 8.56 Granted 60,000 2.04 Outstanding as of December 31, 2020 220,000 $ 3.20 8.04 Vested and exercisable as of December 31, 2020 25,000 $ 1.87 8.82
Summary of stock options granted	The Company used the Black-Scholes option pricing model for determining the estimated fair value of stock-based compensation related to stock options. The table below summarizes the assumptions used: For the Years Ended December 31, 2020 2019 Risk-free interest rate 0.65% - 1.02% 1.77% - 2.72% Expected dividend yield — — Expected term in years 10.0 10.0 Expected volatility 101.27% - 104.60% 99.84% - 103.79%
Summary of warrant activities	A summary of warrant activities for year ended December 31, 2020 and 2019 is presented below: Weighted Average Remaining Weighted Average Contractual Life Warrants Exercise Price (in years) Outstanding as of December 31, 2018 4,280,972 $ 6.69 2.33 Exercised (73,525) — Outstanding as of December 31, 2019 4,207,447 $ 6.81 1.25 Exercised (102,742) 0.13 Expired (4,047,190) 7.00 Outstanding as of December 31, 2020 57,515 $ 5.39 1.22
Summary of stock-based compensation expense	The following table summarizes stock-based compensation expense for the years ended December 31, 2020 and 2019 (in thousands). For the year ended December 31, 2020 2019 Research and development $ 617 $ 707 General and administrative 2,163 2,414 Total stock-based compensation expense $ 2,780 $ 3,121

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2020
Income Taxes
Schedule of effective income tax rate reconciliation	A reconciliation of the statutory U.S. federal rate to the Company’s effective tax rate is as follows: For the Year Ended December 31, 2020 2019 Percentage of pre-tax income: Statutory federal income tax rate 21 % 21 % State taxes, net of federal tax benefit 5 % 6 % Change in state tax rate (1) % 2 % Provision to return 1 % — % Stock based compensation shortfall (1) % (1) % Other (1) % (1) % Change in valuation allowance (24) % (27) % Income taxes provision (benefit) — % — %
Schedule of deferred tax assets	The components of the net deferred tax asset as of December 31, 2020 and 2019 are the following (in thousands): As of December 31, 2020 2019 Deferred tax assets: Net operating loss carryovers $ 27,537 $ 23,051 Stock compensation and other 2,191 2,057 Amortization of license 5,560 4,878 Accruals and reserves 178 184 Tax credits 1,781 1,532 Start Up Costs 28 31 Total deferred tax assets 37,275 31,733 Less valuation allowance (37,275) (31,733) Deferred tax asset, net of valuation allowance $ — $ —

Accounts Payable and Accrued _2

Accounts Payable and Accrued Expenses (Tables)	12 Months Ended
Accounts Payable and Accrued Expenses (Tables)	Dec. 31, 2020
Accounts Payable and Accrued Expenses
Schedule of accounts payable and accrued expenses	At December 31, 2020 and 2019, accounts payable and accrued expenses consisted of the following (in thousands): December 31, 2020 2019 Accounts payable $ 3,438 $ 3,079 Accrued compensation 535 414 Research and development 2,009 3,496 Other 385 268 Total accounts payable and accrued expenses $ 6,367 $ 7,257

Organization and Description _2

Organization and Description of Business Operations - Additional Information (Details) - USD ($)	Feb. 22, 2021	Sep. 30, 2020	Nov. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Retained Earnings (Accumulated Deficit)				$ (143,192,000)	$ (120,111,000)
Stock Issued During Period, Value, New Issues					$ 8,000,000
Common Shares [Member]
Shares Issued, Price Per Share				$ 2.50	$ 2.50
Stock Issued During Period Shares Common Shares For At The Market Offering				5,104,234	2,273,189
Stock Issued During Period Value Common Shares For At The Market Offering Gross				$ 12,800,000	$ 2,273,189,000,000
Stock Issued During Period Value Common Shares For At The Market Offering Net				$ 12,400,000
Underwritten Public Offering [Member]
Stock Issued During Period, Shares, New Issues		7,321,429	15,400,000
Shares Issued, Price Per Share	$ 3.88	$ 2.80	$ 1.27		$ 3.52
Stock Issued During Period, Value, New Issues	$ 12,300,000	$ 20,500,000	$ 19,600,000
Proceeds from Issuance Underwritten Public Offering	12,000,000	18,900,000	17,600,000		$ 7,800,000
Payments of Stock Issuance Costs		$ 1,600,000	$ 2,000,000
Stock Issued During Period Value Common Shares For At The Market Offering Gross	$ 3,170,216

Significant Accounting Polici_4

Significant Accounting Policies - Net Loss per Share (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,147,411	7,671,286
Warrants (Note 6) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	57,515	4,207,447
Stock options (Note 6) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	220,000	160,000
Unvested restricted stock (Note 6) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	3,869,896	3,303,839

Significant Accounting Polici_5

Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	Jan. 01, 2021	Jan. 01, 2020	Mar. 17, 2015	Dec. 31, 2020	Dec. 31, 2019
Equity Method Investment, Annual Equity Fee, Percentage			2.50%
Fortress Biotech, Inc [Member]
Equity Method Investment, Annual Equity Fee, Percentage	2.50%	2.50%		2.50%
Stock Issued During Period, Shares, New Issues	1,742,449	1,459,305		310,625	441,816
Research and development [Member]
Stock Issued During Period, Value, Issued for Services				$ 4.6	$ 2.5

License Agreements (Details)

License Agreements (Details) - USD ($)	Sep. 30, 2015	May 11, 2015	Jun. 30, 2019	May 31, 2016	Mar. 31, 2015	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2016
Neupharma [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment of upfront licensing fees					$ 1,000,000
Neupharma [Member] \| Additional Sales Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						$ 40,000,000
Neupharma [Member] \| Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						40,000,000
Neupharma [Member] \| Regulatory Approvals To Commercialize The Products [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						22,500,000
Dana-Farber [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Stock Issued During Period, Shares, Issued for Services	136,830	500,000
Payment of upfront licensing fees					1,000,000
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		5.00%
Cash In Exchange For Common Stock		$ 10,000,000
Maintenance fee						50,000
Non-Refundable Milestone Payment						925,000
Stock Issued During Period, Value, Issued for Services	$ 600,000	$ 32,500
Shares Issued, Price Per Share		$ 0.065
Dana-Farber [Member] \| First Commercial Sale Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						21,500,000
Dana-Farber [Member] \| Additional Sales Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						60,000,000
Maximum potential milestone payments						$ 60,000,000
Jubilant Biosys Ltd [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment of upfront licensing fees								$ 2,000,000
Revenue recognition milestone revenue recognized							$ 100,000
Proceeds from upfront fees				$ 1,000,000
Research and development cost						50.00%
Jubilant Biosys Ltd [Member] \| Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						$ 89,000,000
Jubilant Biosys Ltd [Member] \| Regulatory Approvals To Commercialize The Products [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						59,500,000
Jubilant Biosys Ltd [Member] \| Five Regulatory Approvals And First Commercial Sales [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						61,700,000
Jubilant Biosys Ltd [Member] \| Sale Millstone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						89,000,000
Maximum potential milestone payments						89,000,000
Jubilant Biosys Ltd [Member] \| Clinical Development and Regulatory Milestones [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						87,200,000
Adimab LLC [Member] \| Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						7,100,000
Adimab LLC [Member] \| Regulatory Approvals To Commercialize The Products [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						4,800,000
Collaboration Agreement With TGTX [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone revenue recognized						1,000,000	$ 1,600,000
Proceeds from upfront fees			$ 1,000,000		$ 500,000
Collaboration Agreement With TGTX [Member] \| First Commercial Sale Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						14,500,000
Collaboration Agreement With TGTX [Member] \| First Commercial Sale Milestone [Member] \| PD-L1 [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Maximum potential milestone payments						27,600,000
Collaboration Agreement With TGTX [Member] \| Clinical and Development Milestone [Member] \| PD-L1 [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						8,400,000
Collaboration Agreement With TGTX [Member] \| Clinical and Development Milestone [Member] \| PD-L1 GITR [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						7,000,000
Collaboration Agreement With TGTX [Member] \| Commercial Sales In Specified Territories [Member] \| PD-L1 [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						19,200,000
Sublicense Agreement with TGTX [Member] \| Clinical and Development Milestone [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						25,500,000
Collaboration Agreement With GITR [Member] \| PD-L1 [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenue recognition milestone payments						$ 21,500,000

Related Party Agreements (Detai

Related Party Agreements (Details)	Mar. 17, 2015USD ($)item	Dec. 31, 2016USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Management Services Agreement [Member]
Related Party Transaction [Line Items]
Number of period	5 years
Annual Consulting Fee	$ 500,000
Increase In Annual Consulting Fee	1,000,000
Excess In Net Assets Value	100,000,000
Costs and Expenses, Related Party			$ 500,000	$ 500,000
Fortress Biotech, Inc [Member] \| Founders Agreement [Member]
Related Party Transaction [Line Items]
Long-term Debt, Gross	$ 2,800,000
Issuance of Common Stock, Percentage of Outstanding Diluted Equity	2.50%
Number of Business Days	5 days
Voting equity, Percentage of Equity or Debt Financing	2.50%
Cash Fee, Percentage of Annual Net Sales	4.50%
Cash Fees, Maximum Number of Days	90 days
Control Fees, Number of Times \| item	5
Control Fees, Monthly Net Sales	12 months
Cash Fee, Percentage of Monthly Net Sales	4.50%
Agreement Term	15 years
Caribe Bioadvisors LLC [Member]
Related Party Transaction [Line Items]
Costs and Expenses, Related Party			111,000	104,000
Annual Advisory Service Fee		$ 60,000
Caribe Bioadvisors LLC [Member] \| Equity Incentive Grants [Member]
Related Party Transaction [Line Items]
Costs and Expenses, Related Party			$ 51,000	$ 44,000

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock (Details) - Unvested restricted stock (Note 6) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Nonvested Beginning Balance	3,303,839	2,932,106
Number of Shares, Granted	1,117,340	800,652
Number of Units, Forfeited		21,000
Number of Shares, Vested	(551,283)	(407,919)
Number of Shares, Nonvested Ending Balance	3,869,896	3,303,839
Weighted Average Exercise Price, Nonvested Beginning Balance	$ 4.29	$ 4.22
Weighted Average Grant Date Fair Value, Granted	2.39	3.33
Weighted Average Grant Date Fair Value, Forfeited		3.16
Weighted Average Grant Date Fair Value, Vested	5.23	1.96
Weighted Average Exercise Price, Nonvested Ending Balance	$ 3.61	$ 4.29

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Options (Details) - Options [Member] - $ / shares	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options, Outstanding (Beginning)		160,000	60,000
Stock Options, Granted		60,000	100,000
Stock Options, Outstanding (Ending)	220,000	220,000	160,000	60,000
Vested and exercisable as of December 31, 2020	25,000	25,000
Weighted Average Exercise Price, Outstanding (Beginning)		$ 3.64	$ 5.43
Weighted Average Exercise Price, Granted		2.04	2.56
Weighted Average Exercise Price, Outstanding (Ending)	$ 3.20	3.20	$ 3.64	$ 5.43
Weighted Average Exercise Price vested and exercisable as of December 31.2020	$ 1.87	$ 1.87
Weighted Average Remaining Contractual Life (in years)	8 years 14 days		8 years 6 months 21 days	8 years 1 month 2 days
Weighted Average vested and exercisable Remaining Contractual Life (in years)		8 years 9 months 25 days

Stockholders' Equity - Option p

Stockholders' Equity - Option pricing model (Details)	12 Months Ended
Stockholders' Equity - Option pricing model (Details)	Dec. 31, 2020	Dec. 31, 2019
Stockholders' Equity
Risk-free interest rate, Minimum	0.65%	1.77%
Risk-free interest rate, Maximum	1.02%	2.72%
Expected dividend yield	0.00%	0.00%
Expected term in years	10 years	10 years
Expected volatility, Minimum	101.27%	99.84%
Expected volatility, Maximum	104.60%	103.79%

Stockholders' Equity - Warrants

Stockholders' Equity - Warrants (Details) - Warrants (Note 6) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrants, Outstanding Beginning Balance	4,207,447	4,280,972
Warrants, Exercised	(102,742)	(73,525)
Warrants, Expired	(4,047,190)
Warrants, Outstanding Ending Balance	57,515	4,207,447	4,280,972
Weighted Average Exercise Price, Nonvested Beginning Balance	$ 6.81	$ 6.69
Weighted Average Exercise Price Exercised	0.13	0
Weighted Average Exercise Price Expired	7
Weighted Average Exercise Price, Nonvested Ending Balance	$ 5.39	$ 6.81	$ 6.69
Weighted Average Remaining Contractual Life, Outstanding (in years)	1 year 2 months 19 days	1 year 3 months	2 years 3 months 29 days

Stockholders' Equity - Stock-Ba

Stockholders' Equity - Stock-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,780	$ 3,121
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	617	707
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,163	$ 2,414

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details) - USD ($)	Feb. 22, 2021	Jan. 01, 2021	Jan. 01, 2020	Mar. 17, 2015	Sep. 30, 2020	Nov. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Nov. 30, 2020	Jun. 04, 2020	Nov. 30, 2017	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized							95,000,000			95,000,000
Common Stock, Increase in authorized shares (in shares)										35,000,000
Common Stock, Par or Stated Value Per Share							$ 0.0001	$ 0.0001		$ 0.0001
Common Stock, Shares, Issued							62,420,439	47,004,764
Common Stock, Shares, Outstanding							62,420,439	47,004,764
Shelf Registration Statement, Maximum Authorized Securities									$ 100,000,000		$ 100,000,000
Percentage of annual equity fee				2.50%
Gross proceeds from issue of shares								$ 8,000,000
Issuance of common shares, net of offering costs - At-the-market offering							$ 12,393,000	7,813,000
Issuance of common shares - Founders Agreement							901,000	$ 738,000
Shelf registration statement remaining authorized securities							83,600,000
Total unrecognized compensation cost related to non-vested							$ 2,800,000
Non-vested Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period (in years)							1 year 10 months 24 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock outstanding non-vested							333,334
2015 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance Authorized												9,000,000
Plans expires (in years)							10 years
Shares are available for issuance							4,288,465
Common Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale price per share							$ 2.50	$ 2.50
Stock Issued During Period Shares Common Shares For At The Market Offering							5,104,234	2,273,189
Stock Issued During Period Value Common Shares For At The Market Offering Gross							$ 12,800,000	$ 2,273,189,000,000
Issuance of common shares, net of offering costs - At-the-market offering							0	0
Issuance of common shares - Founders Agreement							$ 0	$ 0
Underwritten Public Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares sold					7,321,429	15,400,000
Sale price per share	$ 3.88				$ 2.80	$ 1.27		$ 3.52
Gross proceeds from issue of shares	$ 12,300,000				$ 20,500,000	$ 19,600,000
Net proceeds from the offering	12,000,000				18,900,000	17,600,000		$ 7,800,000
Underwriting discounts and offering expenses					$ 1,600,000	$ 2,000,000
Stock Issued During Period Value Common Shares For At The Market Offering Gross	$ 3,170,216
Fortress Biotech, Inc [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares sold		1,742,449	1,459,305				310,625	441,816
Percentage of annual equity fee		2.50%	2.50%				2.50%
Issuance of common shares - Founders Agreement							$ 901,000	$ 738,000
Agent [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Commission rate									3.00%		3.00%
Common Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common Stock, Shares Authorized										7,000,000
Common Stock, Shares, Issued							7,000,000
Common Stock, Shares, Outstanding							7,000,000

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Statutory U.S. Federal Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Percentage of pre-tax income:
Statutory federal income tax rate	21.00%	21.00%
State taxes, net of federal tax benefit	5.00%	6.00%
Change in state tax rate	(1.00%)	2.00%
Provision to return	1.00%	0.00%
Stock based compensation shortfall	(1.00%)	(1.00%)
Other	(1.00%)	(1.00%)
Change in valuation allowance	(24.00%)	(27.00%)
Income taxes provision (benefit)	0.00%	0.00%

Income Taxes - Components of Ne

Income Taxes - Components of Net Deferred Tax Asset (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Net operating loss carryovers	$ 27,537	$ 23,051
Stock compensation and other	2,191	2,057
Amortization of license	5,560	4,878
Accruals and reserves	178	184
Tax credits	1,781	1,532
Start Up Costs	28	31
Total deferred tax assets	37,275	31,733
Less valuation allowance	(37,275)	(31,733)
Deferred tax asset, net of valuation allowance	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets, Valuation Allowance	$ 37,275	$ 31,733
Unrecognized tax benefits interest and penalties accrued	0	$ 0
Research and Development Credit Carryforwards [Member]
Tax Credit Carryforward, Amount	1,100
Orphan Drug Credit Carryforwards [Member]
Tax Credit Carryforward, Amount	$ 700
Tax Credit Carryforward, Expiration Date	Dec. 31, 2035
Domestic Tax Authority [Member]
Operating Loss Carryforwards	$ 101,100
Operating Loss Carry forwards Expiration Period	2035
Federal [Member]
Operating Loss Carryforwards	$ 69,900
Tax Credit Carryforward, Amount	31,200
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	$ 94,900
Operating Loss Carry forwards Expiration Period	2035

Accounts Payable and Accrued _3

Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts Payable and Accrued Expenses
Accounts payable	$ 3,438	$ 3,079
Accrued compensation	535	414
Research and development	2,009	3,496
Other	385	268
Total accounts payable and accrued expenses	$ 6,367	$ 7,257