Celldex Therapeutics (CLDX) 10-Q 4 May 23 2023 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2023	Apr. 28, 2023
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	000-15006
Entity Registrant Name	CELLDEX THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3191702
Entity Address, Address Line One	Perryville III Building
Entity Address, Address Line Two	53 Frontage Road
Entity Address, Address Line Three	Suite 220
Entity Address, City or Town	Hampton
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08827
City Area Code	908
Local Phone Number	200-7500
Title of 12(b) Security	Common Stock, par value $.001
Trading Symbol	CLDX
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		47,252,469
Entity Central Index Key	0000744218
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 54,123	$ 29,429
Marketable securities	224,264	275,523
Accounts and other receivables	1,314	347
Prepaid and other current assets	9,896	12,394
Total current assets	289,597	317,693
Property and equipment, net	3,995	3,747
Operating lease right-of-use assets, net	3,633	4,001
Intangible assets	27,190	27,190
Other assets	104	104
Total assets	324,519	352,735
Current liabilities:
Accounts payable	3,374	3,340
Accrued expenses	9,374	12,835
Current portion of operating lease liabilities	1,493	1,445
Current portion of other long-term liabilities	978	990
Total current liabilities	15,219	18,610
Long-term portion of operating lease liabilities	2,157	2,588
Other long-term liabilities	4,403	5,333
Total liabilities	21,779	26,531
Commitments and contingent liabilities
Stockholders' equity:
Convertible preferred stock, $.01 par value; 3,000,000 shares authorized; no shares issued and outstanding at March 31, 2023 and December 31, 2022		0
Common stock, $.001 par value; 297,000,000 shares authorized; 47,244,681 and 47,200,695 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	47	47
Additional paid-in capital	1,585,863	1,580,829
Accumulated other comprehensive income	2,123	1,260
Accumulated deficit	(1,285,293)	(1,255,932)
Total stockholders' equity	302,740	326,204
Total liabilities and stockholders' equity	$ 324,519	$ 352,735

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2023	Dec. 31, 2022
CONDENSED CONSOLIDATED BALANCE SHEETS
Convertible Preferred Stock, Par Value (in dollars per share)	$ 0.01	$ 0.01
Convertible Preferred Stock, Shares Authorized	3,000,000	3,000,000
Convertible Preferred Stock, Shares Issued	0	0
Convertible Preferred Stock, Shares Outstanding	0	0
Common Stock, Par Value (in dollars per share)	$ 0.001	$ 0.001
Common Stock, Shares Authorized	297,000,000	297,000,000
Common Stock, Shares Issued	47,244,681	47,200,695
Common Stock, Shares Outstanding	47,244,681	47,200,695

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Revenues:
Total revenues	$ 967	$ 174
Operating expenses:
Research and development	26,798	17,056
General and administrative	6,640	6,911
Gain on fair value remeasurement of contingent consideration	0	(536)
Total operating expenses	33,438	23,431
Operating loss	(32,471)	(23,257)
Investment and other income, net	3,110	207
Net loss	$ (29,361)	$ (23,050)
Basic and diluted net loss per common share	$ (0.62)	$ (0.49)
Basic and diluted net loss per common share	$ (0.62)	$ (0.49)
Shares used in calculating basic and diluted net loss per share	47,214	46,739
Shares used in calculating basic and diluted net loss per share	47,214	46,739
Comprehensive loss:
Net loss	$ (29,361)	$ (23,050)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities	863	(1,782)
Comprehensive loss	(28,498)	(24,832)
Product development and licensing agreements
Revenues:
Total revenues		30
Contracts and grants
Revenues:
Total revenues	$ 967	$ 144

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (29,361)	$ (23,050)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	726	811
Amortization and premium of marketable securities, net	(1,256)	772
Gain on fair value remeasurement of contingent consideration	0	(536)
Stock-based compensation expense	4,340	3,153
Changes in operating assets and liabilities:
Accounts and other receivables	(967)	(71)
Prepaid and other current assets	2,722	(7,148)
Accounts payable and accrued expenses	(3,448)	(2,738)
Other liabilities	(1,325)	4,273
Net cash used in operating activities	(28,569)	(24,534)
Cash flows from investing activities:
Sales and maturities of marketable securities	127,000	27,845
Purchases of marketable securities	(73,846)	(16,890)
Acquisition of property and equipment	(585)	(575)
Net cash provided by investing activities	52,569	10,380
Cash flows from financing activities:
Proceeds from issuance of stock from employee benefit plans	694	304
Net cash provided by financing activities	694	304
Net increase (decrease) in cash and cash equivalents	24,694	(13,850)
Cash and cash equivalents at beginning of period	29,429	39,143
Cash and cash equivalents at end of period	54,123	25,293
Non-cash investing activities
Accrued construction in progress	$ 134	$ 53

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2023
Basis of Presentation
Basis of Presentation	(1) Basis of Presentation ​ The accompanying unaudited condensed consolidated financial statements have been prepared by Celldex Therapeutics, Inc. (the “Company” or “Celldex”) in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and reflect the operations of the Company and its wholly-owned subsidiary. All intercompany balances and transactions have been eliminated in consolidation. ​ These interim financial statements do not include all the information and footnotes required by U.S. GAAP for annual financial statements and should be read in conjunction with the audited financial statements for the year ended December 31, 2022, which are included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on February 28, 2023. In the opinion of management, the interim financial statements reflect all normal recurring adjustments necessary to fairly state the Company’s financial position and results of operations for the interim periods presented. The year-end condensed balance sheet data presented for comparative purposes was derived from audited financial statements but does not include all disclosures required by U.S. GAAP. ​ The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for any future interim period or the fiscal year ending December 31, 2023. ​ At March 31, 2023, the Company had cash, cash equivalents and marketable securities of $278.4 million. The Company has had recurring losses and incurred a loss of $29.4 million for the three months ended March 31, 2023. Net cash used in operations for the three months ended March 31, 2023 was $28.6 million. The Company believes that the cash, cash equivalents and marketable securities at the filing date of this Quarterly Report on Form 10-Q will be sufficient to meet estimated working capital requirements and fund planned operations for at least the next twelve months from the date of issuance of these financial statements. ​ During the next twelve months and beyond, the Company may take further steps to raise additional capital to meet its long-term liquidity needs including, but not limited to, one or more of the following: the licensing of drug candidates with existing or new collaborative partners, possible business combinations, issuance of debt, or the issuance of common stock or other securities via private placements or public offerings. Although the Company has been successful in raising capital in the past, there can be no assurance that additional financing will be available on acceptable terms, if at all, and the Company’s negotiating position in capital-raising efforts may worsen as existing resources are used. There is also no assurance that the Company will be able to enter into further collaborative relationships. Additional equity financings may be dilutive to the Company’s stockholders; debt financing, if available, may involve significant cash payment obligations and covenants that restrict the Company’s ability to operate as a business; and licensing or strategic collaborations may result in royalties or other terms which reduce the Company’s economic potential from products under development. The Company’s ability to continue funding its planned operations beyond twelve months from the issuance date is also dependent on the timing and manner of payment of amounts due under the Settlement Agreement with Shareholder Representative Services LLC (“SRS”) (refer to Note 13), in the event that the Company achieves the milestones related to those payments. The Company, at its option, may decide to pay those milestone payments in cash, shares of its common stock or a combination thereof. If the Company is unable to raise the funds necessary to meet its long-term liquidity needs, it may have to delay or discontinue the development of one or more programs, discontinue or delay ongoing or anticipated clinical trials, license out programs earlier than expected, raise funds at a significant discount or on other unfavorable terms, if at all, or sell all or a part of the Company.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Significant Accounting Policies
Significant Accounting Policies	(2) Significant Accounting Policies ​ The significant accounting policies used in preparation of these condensed consolidated financial statements on this Quarterly Report on Form 10-Q for the three months ended March 31, 2023 are consistent with those discussed in Note 2 to the financial statements in our Annual Report on Form 10-K for the year ended December 31, 2022, except as it relates to the adoption of new accounting standards during the first three months of 2023 as discussed below. ​ Newly Adopted Accounting Pronouncements On January 1, 2023, the Company adopted ASU 2016-13: Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The guidance requires that credit losses be reported using an expected losses model rather than the incurred losses model and establishes additional disclosure requirements related to credit risks. For available-for-sale debt securities with unrealized losses, the standard requires allowances to be recorded instead of reducing the amortized cost of the investment. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements and related disclosures. Recent Accounting Pronouncements ​ From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. The Company has reviewed recently issued accounting pronouncements and concluded they are either not applicable to the business or not expected to have a material impact on the Company’s consolidated financial statements as a result of future adoption. ​

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2023
Fair Value Measurements
Fair Value Measurements	(3) Fair Value Measurements ​ The following tables set forth the Company’s financial assets and liabilities subject to fair value measurements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2023 Level 1 Level 2 Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 54,089 ​ ​ — ​ $ 54,089 ​ ​ — Marketable securities ​ ​ 224,264 ​ ​ — ​ ​ 224,264 ​ ​ — ​ ​ $ 278,353 ​ ​ — ​ $ 278,353 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 Level 1 Level 2 Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 16,813 ​ ​ — ​ $ 16,813 ​ ​ — Marketable securities ​ ​ 275,523 ​ ​ — ​ ​ 275,523 ​ ​ — ​ ​ $ 292,336 ​ ​ — ​ $ 292,336 ​ ​ — ​ The Company’s financial assets consist mainly of money market funds, cash equivalents and marketable securities and are classified as Level 2 within the valuation hierarchy. The Company values its marketable securities utilizing independent pricing services which normally derive security prices from recently reported trades for identical or similar securities, making adjustments based on significant observable transactions. At each balance sheet date, observable market inputs may include trade information, broker or dealer quotes, bids, offers or a combination of these data sources. ​ Contingent consideration liabilities measured at fair value using Level 3 inputs were $0.0 million as of March 31, 2023 and December 31, 2022. The valuation technique used to measure fair value of the Company’s Level 3 liabilities, which consist of contingent consideration related to the acquisition of Kolltan Pharmaceuticals, Inc. (“Kolltan”) in 2016, is primarily an income approach. The significant unobservable inputs used in the fair value measurement of the contingent consideration are estimates including probability of success, discount rates and amount of time until the conditions of the milestone payments are met. ​ During the three months ended March 31, 2023, there was no gain or loss on fair value remeasurement of contingent consideration. During the three months ended March 31, 2022, the Company recorded a $0.5 million gain on fair value remeasurement of contingent consideration primarily due to changes in discount rates. The assumptions related to determining the fair value of contingent consideration include a significant amount of judgment, and any changes in the underlying estimates could have a material impact on the amount of contingent consideration adjustment recorded in any given period. ​ The Company did not have any transfers in or out of Level 3 assets liabilities during

Marketable Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2023
Marketable Securities
Marketable Securities	(4) Marketable Securities ​ The following is a summary of marketable debt securities, classified as available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Unrealized ​ ​ Amortized ​ ​ ​ ​ ​ ​ ​ Fair ​ Cost Gains Losses Value ​ ​ (In thousands) March 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 81,514 ​ $ 47 ​ $ (51) ​ $ 81,510 Maturing after one year through three years ​ ​ 15,064 ​ ​ 12 ​ ​ — ​ ​ 15,076 Total U.S. government and municipal obligations ​ $ 96,578 ​ $ 59 ​ $ (51) ​ $ 96,586 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 128,159 ​ $ — ​ $ (481) ​ $ 127,678 Maturing after one year through three years ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total corporate debt securities ​ $ 128,159 ​ $ — ​ $ (481) ​ $ 127,678 Total marketable securities ​ $ 224,737 ​ $ 59 ​ $ (532) ​ $ 224,264 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Unrealized ​ ​ Amortized ​ ​ ​ ​ ​ ​ ​ Fair ​ ​ Cost Gains Losses Value ​ ​ (In thousands) December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 97,246 ​ $ 5 ​ $ (369) ​ $ 96,882 Maturing after one year through three years ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total U.S. government and municipal obligations ​ $ 97,246 ​ $ 5 ​ $ (369) ​ $ 96,882 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 179,613 ​ $ — ​ $ (972) ​ $ 178,641 Maturing after one year through three years ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total corporate debt securities ​ $ 179,613 ​ $ — ​ $ (972) ​ $ 178,641 Total marketable securities ​ $ 276,859 ​ $ 5 ​ $ (1,341) ​ $ 275,523 ​ The Company holds investment-grade marketable securities, and none were in a continuous unrealized loss position for more than twelve months as of March 31, 2023 and December 31, 2022. The unrealized losses are attributable to changes in interest rates and the Company does not believe any unrealized losses represent other-than-temporary impairments. The Company has the intent and ability to hold such marketable securities until recovery and has determined that there has been no material change to their credit risk. As a result, the Company determined it did not hold any investments with a credit loss at March 31, 2023. Marketable securities include $0.6 million and $0.8 million in accrued interest at March 31, 2023 and December 31, 2022, respectively.

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2023
Intangible Assets
Intangible Assets	(5) Intangible Assets ​ At March 31, 2023 and December 31, 2022, the carrying value of the Company’s indefinite-lived intangible assets was $27.2 million. Indefinite-lived intangible assets consist of acquired IPR&D related to the development of the anti-KIT program, including barzolvolimab (also referred to as CDX-0159), which was recorded in connection with the Kolltan acquisition. Barzolvolimab is in Phase 2 development. As of March 31, 2023, the IPR&D asset related to the anti-KIT program had not reached technological feasibility nor did the asset have alternative future uses. The Company performs an impairment test on IPR&D assets at least annually, or more frequently if events or changes in circumstances indicate that IPR&D assets may be impaired. Due to the nature of IPR&D projects, the Company may experience future delays or failures to obtain regulatory approvals to conduct clinical trials, failures of such clinical trials or other failures to achieve a commercially viable product, and as a result, may recognize further impairment losses in the future. ​

Other Long-Term Liabilities

Other Long-Term Liabilities	3 Months Ended
	Mar. 31, 2023
Other Long-Term Liabilities
Other Long-Term Liabilities	(6) Other Long-Term Liabilities ​ Other long-term liabilities include the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2023 ​ 2022 ​ ​ (In thousands) Net deferred tax liabilities related to IPR&D (Note 11) ​ $ 1,613 ​ $ 1,613 Deferred Income From Sale of Tax Benefits ​ 3,720 ​ 4,650 Deferred revenue (Note 10) ​ 48 ​ 60 Total ​ 5,381 ​ 6,323 Less current portion ​ (978) ​ (990) Long-term portion ​ $ 4,403 ​ $ 5,333 ​ In March 2022, the Company received approval from the New Jersey Economic Development Authority and agreed to sell New Jersey tax benefits of $5.0 million to an independent third party for $4.7 million. Under the agreement, the Company must maintain a base of operations in New Jersey for five years or the tax benefits must be paid back on a pro-rata basis based on the number of years completed. The Company recognized $0.9 million in other income related to the sale of these tax benefits during the three months ended March 31, 2023.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2023
Stockholders' Equity
Stockholders' Equity	(7) Stockholders’ Equity ​ In May 2016, the Company entered into a controlled equity offering sales agreement (the “Cantor Agreement”) with Cantor Fitzgerald & Co. (“Cantor”) to allow the Company to issue and sell shares of its common stock from time to time through Cantor, acting as agent. At March 31, 2023, the Company had $50.0 million remaining in aggregate gross offering price available under the Company’s November 2020 prospectus. ​ The changes in Stockholders’ Equity during the three months ended March 31, 2023 and 2022 are summarized below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ Common ​ Common ​ Additional ​ Other ​ ​ ​ ​ Total ​ ​ Stock ​ Stock Par ​ Paid-In ​ Comprehensive ​ Accumulated ​ Stockholders’ ​ Shares Value Capital Income Deficit Equity ​ ​ (In thousands, except share amounts) Consolidated balance at December 31, 2022 47,200,695 $ 47 $ 1,580,829 $ 1,260 $ (1,255,932) $ 326,204 Shares issued under stock option and employee stock purchase plans 43,986 — 694 — — 694 Stock-based compensation — — 4,340 — — 4,340 Unrealized gain on marketable securities — — — 863 — 863 Net loss — — — — (29,361) ​ (29,361) Consolidated balance at March 31, 2023 47,244,681 $ 47 $ 1,585,863 $ 2,123 $ (1,285,293) $ 302,740 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ Common ​ Common ​ Additional ​ Other ​ ​ ​ ​ Total ​ ​ Stock ​ Stock Par ​ Paid-In ​ Comprehensive ​ Accumulated ​ Stockholders’ ​ ​ Shares ​ Value ​ Capital ​ Income ​ Deficit ​ Equity ​ ​ (In thousands, except share amounts) Consolidated balance at December 31, 2021 46,730,198 ​ $ 47 ​ $ 1,561,142 ​ $ 1,894 ​ $ (1,143,607) ​ $ 419,476 Shares issued under stock option and employee stock purchase plans 24,150 ​ — ​ 304 ​ — ​ — ​ 304 Stock-based compensation — ​ — ​ 3,153 ​ — ​ — ​ 3,153 Unrealized loss on marketable securities — ​ — ​ — ​ (1,782) ​ — ​ (1,782) Net loss — ​ — ​ — ​ — ​ (23,050) ​ (23,050) Consolidated balance at March 31, 2022 46,754,348 ​ $ 47 ​ $ 1,564,599 ​ $ 112 ​ $ (1,166,657) ​ $ 398,101 ​

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2023
Stock-Based Compensation
Stock-Based Compensation	(8) Stock-Based Compensation ​ A summary of stock option activity for the three months ended March 31, 2023 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ Average ​ Average ​ ​ ​ ​ Exercise ​ Remaining ​ ​ ​ ​ Price ​ Contractual ​ Shares Per Share Term (In Years) Options outstanding at December 31, 2022 5,085,662 ​ $ 29.26 ​ 7.9 Granted 26,900 ​ $ 43.17 ​ ​ Exercised (37,492) ​ $ 15.18 ​ ​ Canceled (107,306) ​ $ 20.95 ​ ​ Options outstanding at March 31, 2023 4,967,764 ​ $ 29.62 ​ 7.6 Options vested and expected to vest at March 31, 2023 4,884,568 ​ $ 29.72 ​ 7.6 Options exercisable at March 31, 2023 2,273,841 ​ $ 38.18 ​ 6.4 Shares available for grant under the 2021 Plan 1,918,374 ​ ​ ​ ​ ​ ​ The weighted average grant-date fair value of stock options granted during the three months ended March 31, 2023 was $33.25. ​ The aggregate intrinsic value of stock options vested and expected to vest at March 31, 2023 was $78.1 million. The aggregate intrinsic value of stock options exercisable at March 31, 2023 was $42.0 million. As of March 31, 2023, total compensation cost related to non-vested employee, consultant and non-employee director stock options not yet recognized was approximately $38.3 million, net of estimated forfeitures, which is expected to be recognized as expense over a weighted average period of 2.5 years. ​ Stock-based compensation expense for the three months ended March 31, 2023 and 2022 was recorded as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, ​ 2023 2022 ​ ​ (In thousands) Research and development ​ $ 2,162 ​ $ 1,614 General and administrative ​ 2,178 ​ 1,539 Total stock-based compensation expense ​ $ 4,340 ​ $ 3,153 ​ The fair values of employee, consultant and non-employee director stock options granted during the three months ended March 31, 2023 and 2022 were valued using the Black-Scholes option pricing model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, 2023 2022 Expected stock price volatility 92% ​ 91 - 97% Expected option term 6.0 Years ​ 6.0 Years Risk-free interest rate 3.7 - 4.0% ​ 1.7 - 1.9% Expected dividend yield None ​ None ​

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2023
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income	(9) Accumulated Other Comprehensive Income ​ The changes in accumulated other comprehensive income, which is reported as a component of stockholders’ equity, for the three months ended March 31, 2023 are summarized below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized ​ ​ ​ ​ ​ ​ ​ ​ Loss on ​ ​ ​ ​ ​ ​ ​ ​ Marketable ​ Foreign ​ ​ ​ ​ Securities Currency Items Total ​ ​ (In thousands) Balance at December 31, 2022 ​ $ (1,336) ​ $ 2,596 ​ $ 1,260 Other comprehensive gain ​ 863 ​ — ​ 863 Balance at March 31, 2023 ​ $ (473) ​ $ 2,596 ​ $ 2,123 ​ No amounts were reclassified out of accumulated other comprehensive income during the three months ended March 31, 2023.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2023
Revenue
Revenue	(10) Revenue ​ Contract and Grants Revenue ​ The Company has entered into an agreement with Rockefeller University pursuant to which the Company performs manufacturing and research and development services on a time-and-materials basis or at a negotiated fixed-price. The Company recognized $1.0 million and $0.1 in revenue under this agreement during the three months ended March 31, 2023, and 2022, respectively. ​ Contract Assets and Liabilities ​ At March 31, 2023 and December 31, 2022, the Company’s right to consideration under all contracts was considered unconditional, and as such, there were no recorded contract assets. At March 31, 2023, the Company had $0.0 million in contract liabilities recorded. At December 31, 2022, the Company had $0.1 million in contract liabilities recorded. Revenue recognized from contract liabilities as of December 31, 2022 during the three ended March 31, 2023 was $0.0 million.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
Income Taxes
Income Taxes	(11) Income Taxes ​ The Company has evaluated the positive and negative evidence bearing upon the realizability of its net deferred tax assets and considered its history of losses, ultimately concluding that it is “more likely than not” that the Company will not recognize the benefits of federal, state and foreign deferred tax assets and, as such, has maintained a full valuation allowance on its deferred tax assets as of March 31, 2023 and December 31, 2022. ​ The net deferred tax liability of $1.6 million at March 31, 2023 and December 31, 2022 relates to the temporary differences associated with the IPR&D intangible assets acquired in previous business combinations and is not deductible for tax purposes. ​ Massachusetts, New Jersey, New York and Connecticut are the jurisdictions in which the Company primarily operates or has operated and has income tax nexus. The Company is not currently under examination by these or any other jurisdictions for any tax year.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2023
Net Loss Per Share
Net Loss Per Share	(12) Net Loss Per Share ​ Basic net loss per common share is based upon the weighted-average number of common shares outstanding during the period, excluding restricted stock that has been issued but is not yet vested. Diluted net loss per common share is based upon the weighted-average number of common shares outstanding during the period plus additional weighted-average potentially dilutive common shares outstanding during the period when the effect is dilutive. In periods in which the Company reports a net loss, there is no difference between basic and diluted net loss per share because dilutive shares of common stock are not assumed to have been issued as their effect is anti-dilutive. The potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive are as follows: ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2023 2022 Stock Options 4,967,764 4,064,557 Restricted Stock — — ​ 4,967,764 4,064,557 ​

Kolltan Acquisition

Kolltan Acquisition	3 Months Ended
	Mar. 31, 2023
Kolltan Acquisition
Kolltan Acquisition	(13) Kolltan Acquisition ​ On November 29, 2016, the Company acquired all of the share and debt interests of Kolltan, a clinical-stage biopharmaceutical company, in exchange for 1,217,200 shares of the Company’s common stock plus contingent consideration in the form of development, regulatory approval and sales-based milestones (“Kolltan Milestones”) of up to $172.5 million payable in cash, in shares of Celldex’s common stock or a combination of both, in the sole discretion of Celldex and subject to provisions of the Agreement and Plan of Merger, dated November 1, 2016 (the “Merger Agreement”). ​ In October 2019, the Company received a letter from SRS, the hired representative of the former stockholders of Kolltan, notifying the Company that it objected to the Company’s characterization of the development, regulatory approval and sales-based Kolltan Milestones relating to CDX-0158 as having been abandoned and contending instead that the related milestone payments are due from Celldex to the Kolltan stockholder. ​ On August 18, 2020, Celldex filed a Verified Complaint in the Court of Chancery of the State of Delaware against SRS (acting in its capacity as the representative of the former stockholders of Kolltan pursuant to the Merger Agreement) seeking declaratory relief with respect to the rights and obligations of the parties relating to certain contingent milestone payments under the Merger Agreement relating to the discontinued CDX-0158 program (the “Litigation”). ​ On June 20, 2022, the Company entered into a binding settlement term sheet (the “Term Sheet”) with SRS, related to the Litigation, which, upon execution of a definitive settlement agreement and the payment of the Initial Payment (as defined below), would result in the joint dismissal, with prejudice, of all claims and counterclaims in the Litigation. The definitive settlement agreement between the Company and SRS was executed on July 15, 2022 (the “Settlement Agreement”) and the Company and SRS jointly filed a Stipulation of Dismissal with prejudice relating to the Litigation on July 19, 2022. ​ Pursuant to the terms of the Term Sheet and the Settlement Agreement, all milestone payments provided for by the Merger Agreement are replaced in their entirety with the following payments, each of which is payable only once: ​ (i) The Company paid $ 15.0 million upon execution of the Settlement Agreement (the “Initial Payment”). ​ (ii) The Company shall pay $ 15.0 million upon the Successful Completion (as defined in the Term Sheet) of a Phase 2 Clinical Trial (as defined in the Merger Agreement) of CDX-0159, subject to the $ 2.5 million contractual credit as set forth in the Merger Agreement. ​ (iii) The Company shall pay $ 52.5 million upon the first United States Food and Drug Administration or European Medicines Agency, or, in each case, any successor organization, regulatory approval of a Surviving Company Product (as defined the Term Sheet). ​ The above payment obligations replace, in their entirety, the contingent consideration in the form of development, regulatory approval and sales-based milestones of up to $172.5 million contained in the Merger Agreement. ​ Under the Settlement Agreement, each of the Company and SRS provided broad mutual releases of all claims relating to or arising out of the Merger Agreement, including without limitation, all claims brought in the Litigation or that could have been brought in the Litigation. ​ The Company paid the Initial Payment in cash during the three months ended September 30, 2022. Any future milestone payments related to the CDX-0159 program, which was subject to the Litigation, will be recorded when and if payment becomes probable and reasonably estimable in accordance with the loss contingency model under ASC 450. Milestones related to the remaining Surviving Company Products are measured at fair value (refer to Note 3). When and if any of the remaining payments described above become due, they shall be payable, at the Company’s sole election, in either cash or stock (as set forth in the Merger Agreement) or a combination thereof. ​

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2023
Significant Accounting Policies
Newly-Adopted Accounting Pronouncements	Newly Adopted Accounting Pronouncements On January 1, 2023, the Company adopted ASU 2016-13: Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The guidance requires that credit losses be reported using an expected losses model rather than the incurred losses model and establishes additional disclosure requirements related to credit risks. For available-for-sale debt securities with unrealized losses, the standard requires allowances to be recorded instead of reducing the amortized cost of the investment. The adoption of this guidance did not have a material impact on the Company’s consolidated financial statements and related disclosures.
Recent Accounting Pronouncements	Recent Accounting Pronouncements ​ From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies that are adopted by the Company as of the specified effective date. The Company has reviewed recently issued accounting pronouncements and concluded they are either not applicable to the business or not expected to have a material impact on the Company’s consolidated financial statements as a result of future adoption.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Measurements
Schedule of financial assets and liabilities subject to fair value measurements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, 2023 Level 1 Level 2 Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 54,089 ​ ​ — ​ $ 54,089 ​ ​ — Marketable securities ​ ​ 224,264 ​ ​ — ​ ​ 224,264 ​ ​ — ​ ​ $ 278,353 ​ ​ — ​ $ 278,353 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 Level 1 Level 2 Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 16,813 ​ ​ — ​ $ 16,813 ​ ​ — Marketable securities ​ ​ 275,523 ​ ​ — ​ ​ 275,523 ​ ​ — ​ ​ $ 292,336 ​ ​ — ​ $ 292,336 ​ ​ — ​

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2023
Marketable Securities
Schedule of marketable debt securities, classified as available-for-sale	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Unrealized ​ ​ Amortized ​ ​ ​ ​ ​ ​ ​ Fair ​ Cost Gains Losses Value ​ ​ (In thousands) March 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 81,514 ​ $ 47 ​ $ (51) ​ $ 81,510 Maturing after one year through three years ​ ​ 15,064 ​ ​ 12 ​ ​ — ​ ​ 15,076 Total U.S. government and municipal obligations ​ $ 96,578 ​ $ 59 ​ $ (51) ​ $ 96,586 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 128,159 ​ $ — ​ $ (481) ​ $ 127,678 Maturing after one year through three years ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total corporate debt securities ​ $ 128,159 ​ $ — ​ $ (481) ​ $ 127,678 Total marketable securities ​ $ 224,737 ​ $ 59 ​ $ (532) ​ $ 224,264 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Unrealized ​ ​ Amortized ​ ​ ​ ​ ​ ​ ​ Fair ​ ​ Cost Gains Losses Value ​ ​ (In thousands) December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 97,246 ​ $ 5 ​ $ (369) ​ $ 96,882 Maturing after one year through three years ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total U.S. government and municipal obligations ​ $ 97,246 ​ $ 5 ​ $ (369) ​ $ 96,882 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 179,613 ​ $ — ​ $ (972) ​ $ 178,641 Maturing after one year through three years ​ ​ — ​ ​ — ​ ​ — ​ ​ — Total corporate debt securities ​ $ 179,613 ​ $ — ​ $ (972) ​ $ 178,641 Total marketable securities ​ $ 276,859 ​ $ 5 ​ $ (1,341) ​ $ 275,523 ​

Other Long-Term Liabilities (Ta

Other Long-Term Liabilities (Tables)	3 Months Ended
	Mar. 31, 2023
Other Long-Term Liabilities
Schedule of other long-term liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2023 ​ 2022 ​ ​ (In thousands) Net deferred tax liabilities related to IPR&D (Note 11) ​ $ 1,613 ​ $ 1,613 Deferred Income From Sale of Tax Benefits ​ 3,720 ​ 4,650 Deferred revenue (Note 10) ​ 48 ​ 60 Total ​ 5,381 ​ 6,323 Less current portion ​ (978) ​ (990) Long-term portion ​ $ 4,403 ​ $ 5,333 ​

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2023
Stockholders' Equity
Schedule of shareholder's equity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ Common ​ Common ​ Additional ​ Other ​ ​ ​ ​ Total ​ ​ Stock ​ Stock Par ​ Paid-In ​ Comprehensive ​ Accumulated ​ Stockholders’ ​ Shares Value Capital Income Deficit Equity ​ ​ (In thousands, except share amounts) Consolidated balance at December 31, 2022 47,200,695 $ 47 $ 1,580,829 $ 1,260 $ (1,255,932) $ 326,204 Shares issued under stock option and employee stock purchase plans 43,986 — 694 — — 694 Stock-based compensation — — 4,340 — — 4,340 Unrealized gain on marketable securities — — — 863 — 863 Net loss — — — — (29,361) ​ (29,361) Consolidated balance at March 31, 2023 47,244,681 $ 47 $ 1,585,863 $ 2,123 $ (1,285,293) $ 302,740 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ Common ​ Common ​ Additional ​ Other ​ ​ ​ ​ Total ​ ​ Stock ​ Stock Par ​ Paid-In ​ Comprehensive ​ Accumulated ​ Stockholders’ ​ ​ Shares ​ Value ​ Capital ​ Income ​ Deficit ​ Equity ​ ​ (In thousands, except share amounts) Consolidated balance at December 31, 2021 46,730,198 ​ $ 47 ​ $ 1,561,142 ​ $ 1,894 ​ $ (1,143,607) ​ $ 419,476 Shares issued under stock option and employee stock purchase plans 24,150 ​ — ​ 304 ​ — ​ — ​ 304 Stock-based compensation — ​ — ​ 3,153 ​ — ​ — ​ 3,153 Unrealized loss on marketable securities — ​ — ​ — ​ (1,782) ​ — ​ (1,782) Net loss — ​ — ​ — ​ — ​ (23,050) ​ (23,050) Consolidated balance at March 31, 2022 46,754,348 ​ $ 47 ​ $ 1,564,599 ​ $ 112 ​ $ (1,166,657) ​ $ 398,101

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2023
Stock-Based Compensation
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ Weighted ​ ​ ​ ​ Average ​ Average ​ ​ ​ ​ Exercise ​ Remaining ​ ​ ​ ​ Price ​ Contractual ​ Shares Per Share Term (In Years) Options outstanding at December 31, 2022 5,085,662 ​ $ 29.26 ​ 7.9 Granted 26,900 ​ $ 43.17 ​ ​ Exercised (37,492) ​ $ 15.18 ​ ​ Canceled (107,306) ​ $ 20.95 ​ ​ Options outstanding at March 31, 2023 4,967,764 ​ $ 29.62 ​ 7.6 Options vested and expected to vest at March 31, 2023 4,884,568 ​ $ 29.72 ​ 7.6 Options exercisable at March 31, 2023 2,273,841 ​ $ 38.18 ​ 6.4 Shares available for grant under the 2021 Plan 1,918,374 ​ ​ ​ ​ ​ ​
Schedule of stock-based compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, ​ 2023 2022 ​ ​ (In thousands) Research and development ​ $ 2,162 ​ $ 1,614 General and administrative ​ 2,178 ​ 1,539 Total stock-based compensation expense ​ $ 4,340 ​ $ 3,153 ​
Schedule of assumptions used for the fair value of employee stock options granted	​ ​ ​ ​ ​ ​ ​ ​ Three months ended March 31, 2023 2022 Expected stock price volatility 92% ​ 91 - 97% Expected option term 6.0 Years ​ 6.0 Years Risk-free interest rate 3.7 - 4.0% ​ 1.7 - 1.9% Expected dividend yield None ​ None

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2023
Accumulated Other Comprehensive Income
Schedule of changes in accumulated other comprehensive income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized ​ ​ ​ ​ ​ ​ ​ ​ Loss on ​ ​ ​ ​ ​ ​ ​ ​ Marketable ​ Foreign ​ ​ ​ ​ Securities Currency Items Total ​ ​ (In thousands) Balance at December 31, 2022 ​ $ (1,336) ​ $ 2,596 ​ $ 1,260 Other comprehensive gain ​ 863 ​ — ​ 863 Balance at March 31, 2023 ​ $ (473) ​ $ 2,596 ​ $ 2,123 ​

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2023
Net Loss Per Share
Schedule of potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive	​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ 2023 2022 Stock Options 4,967,764 4,064,557 Restricted Stock — — ​ 4,967,764 4,064,557

Basis of Presentation (Details)

Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Basis of Presentation
Cash, cash equivalents and marketable securities	$ 278,400
Net loss	(29,361)	$ (23,050)
Net cash used in operations	$ (28,569)	$ (24,534)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Fair Value Measurements - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Level 1
Assets:
Money market funds and cash equivalents	$ 0
Marketable securities	0
Total financial assets at fair value measurements	0
Level 2
Assets:
Money market funds and cash equivalents	54,089	$ 16,813
Marketable securities	224,264	275,523
Total financial assets at fair value measurements	278,353	292,336
Level 3
Assets:
Money market funds and cash equivalents	0
Marketable securities	0
Total financial assets at fair value measurements	0
Fair value
Assets:
Money market funds and cash equivalents	54,089	16,813
Marketable securities	224,264	275,523
Total financial assets at fair value measurements	$ 278,353	$ 292,336

Fair Value Measurements - Addit

Fair Value Measurements - Additional information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Fair value measurements
Gain on fair value remeasurement of contingent consideration	$ 0	$ 536
Fair value
Fair value measurements
Asset transfer out of level 3	0
Asset transfer into level 3	0
Liabilities transfers out of level 3	0
Fair value | Level 3
Fair value measurements
Contingent consideration liabilities	$ 0		$ 0

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Amortized Cost
Amortized Cost	$ 224,737	$ 276,859
Gross Unrealized Gains
Gross Unrealized Gains	59	5
Gross Unrealized Losses
Gross Unrealized Losses	(532)	(1,341)
Fair Value
Fair Value	224,264	275,523
U.S. government and municipal obligations
Amortized Cost
Maturing in one year or less	81,514	97,246
Maturing after one year through three years	15,064
Amortized Cost	96,578	97,246
Gross Unrealized Gains
Maturing in one year or less	47	5
Maturing after one year through three years	12	0
Gross Unrealized Gains	59	5
Gross Unrealized Losses
Maturing in one year or less	(51)	(369)
Gross Unrealized Losses	(51)	(369)
Fair Value
Maturing in one year or less	81,510	96,882
Maturing after one year through three years	15,076
Fair Value	96,586	96,882
Corporate debt securities
Amortized Cost
Maturing in one year or less	128,159	179,613
Amortized Cost	128,159	179,613
Gross Unrealized Gains
Maturing in one year or less		0
Maturing after one year through three years		0
Gross Unrealized Gains		0
Gross Unrealized Losses
Maturing in one year or less	(481)	(972)
Gross Unrealized Losses	(481)	(972)
Fair Value
Maturing in one year or less	127,678	178,641
Fair Value	$ 127,678	$ 178,641

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Marketable Securities
Number of investment-grade securities in unrealized loss position over 12 months	$ 0	$ 0
Accrued interest	$ 600	$ 800

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Intangible Assets
Indefinite-lived intangible assets	$ 27.2	$ 27.2

Other Long-Term Liabilities (De

Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Other Long-Term Liabilities
Net deferred tax liabilities related to IPR&D	$ 1,613	$ 1,613
Deferred Income From Sale of Tax Benefits	3,720	4,650
Deferred revenue	48	60
Total	5,381	6,323
Less current portion	(978)	(990)
Long-term portion	$ 4,403	$ 5,333

Other Long-Term Liabilities- Ne

Other Long-Term Liabilities- New Jersey tax benefits (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Other Long-Term Liabilities
Other income		$ 3,110	$ 207
New Jersey tax benefits
Other Long-Term Liabilities
Amount of tax benefit	$ 5,000
Proceeds from sale of tax credits	$ 4,700
Base of operations requirement (in years)	5 years
New Jersey Economic Development Authority
Other Long-Term Liabilities
Other income		$ 900

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Common Stock
Balance, beginning	$ 326,204	$ 419,476
Balance (in shares)	47,200,695
Shares issued under stock option and employee stock purchase plans	$ 694	304
Stock-based compensation	4,340	3,153
Unrealized loss on marketable securities	863	(1,782)
Net loss	(29,361)	(23,050)
Balance, ending	$ 302,740	398,101
Balance (in shares)	47,244,681
Aggregate gross offering price available	$ 50,000
Common Stock [Member]
Common Stock
Balance, beginning	$ 47	$ 47
Balance (in shares)	47,200,695	46,730,198
Shares issued under stock option and employee stock purchase plans	$ 0
Shares issued under stock option and employee stock purchase plans (in shares)	43,986	24,150
Stock-based compensation	$ 0
Unrealized loss on marketable securities	0
Net loss	0
Balance, ending	$ 47	$ 47
Balance (in shares)	47,244,681	46,754,348
Additional Paid-in Capital [Member]
Common Stock
Balance, beginning	$ 1,580,829	$ 1,561,142
Shares issued under stock option and employee stock purchase plans	694	304
Stock-based compensation	4,340	3,153
Unrealized loss on marketable securities	0
Net loss	0
Balance, ending	1,585,863	1,564,599
AOCI Attributable to Parent [Member]
Common Stock
Balance, beginning	1,260	1,894
Shares issued under stock option and employee stock purchase plans	0
Stock-based compensation	0
Unrealized loss on marketable securities	863	(1,782)
Net loss	0
Balance, ending	2,123	112
Retained Earnings [Member]
Common Stock
Balance, beginning	(1,255,932)	(1,143,607)
Shares issued under stock option and employee stock purchase plans	0
Stock-based compensation	0
Unrealized loss on marketable securities	0
Net loss	(29,361)	(23,050)
Balance, ending	$ (1,285,293)	$ (1,166,657)

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - Stock options - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Shares
Options outstanding at beginning of the period (in shares)	5,085,662
Granted (in shares)	26,900
Exercised (in shares)	(37,492)
Canceled (in shares)	(107,306)
Options outstanding at the end of the period (in shares)	4,967,764	5,085,662
Options vested and expected to vest at the end of the period (in shares)	4,884,568
Options exercisable at the end of the period (in shares)	2,273,841
Shares available for grant under the 2021 Plan	1,918,374
Weighted Average Exercise Price Per Share
Options outstanding at beginning of the period (in dollars per share)	$ 29.26
Granted (in dollars per share)	43.17
Exercised (in dollars per share)	15.18
Canceled (in dollars per share)	20.95
Options outstanding at the end of the period (in dollars per share)	29.62	$ 29.26
Options vested and expected to Vest at the end of the period (in dollars per share)	29.72
Options exercisable at the end of the period (in dollars per share)	$ 38.18
Weighted Average Remaining Contractual Term (In Years)
Options outstanding at the end of the period	7 years 7 months 6 days	7 years 10 months 24 days
Options vested and expected to vest at the end of the period	7 years 7 months 6 days
Options exercisable at the end of the period	6 years 4 months 24 days

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee Stock Option and Incentive Plan (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) $ / shares
Stock-Based Compensation
Weighted average grant-date fair value (in dollars per share) | $ / shares	$ 33.25
Intrinsic value of options vested and expected to vest	$ 78.1
Intrinsic value of options exercisable	42
Compensation cost not yet recognized	$ 38.3
Weighted average period compensation cost is expected to be recognized (in years)	2 years 6 months

Stock-Based Compensation - Expe

Stock-Based Compensation - Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Stock-based compensation expense
Total stock-based compensation expense	$ 4,340	$ 3,153
Research and development
Stock-based compensation expense
Total stock-based compensation expense	2,162	1,614
General and administrative
Stock-based compensation expense
Total stock-based compensation expense	$ 2,178	$ 1,539

Stock-Based Compensation - Valu

Stock-Based Compensation - Valuation (Details) - Stock options	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Black-Scholes option with following assumptions:
Expected stock price volatility (as a percent)	92%
Expected stock price volatility, minimum (as a percent)		91%
Expected stock price volatility, maximum (as a percent)		97%
Expected option term	6 years	6 years
Risk-free interest rate, minimum (as a percent)	3.70%	1.70%
Risk-free interest rate, maximum (as a percent)	4%	1.90%
Expected dividend yield (as a percent)	0%	0%

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Accumulated Other Comprehensive Income
Balance, beginning	$ 326,204
Balance, ending	302,740
Amounts reclassified from AOCI	0
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income
Balance, beginning	1,260
Other comprehensive gain	863
Balance, ending	2,123
Unrealized Loss on Marketable Securities
Accumulated Other Comprehensive Income
Balance, beginning	(1,336)
Other comprehensive gain	863
Balance, ending	(473)
Foreign Currency Items
Accumulated Other Comprehensive Income
Balance, beginning	2,596
Other comprehensive gain	0
Balance, ending	$ 2,596

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Revenue
Revenues	$ 967	$ 174
Contract assets	0		$ 0
Contract liability	48		$ 60
Revenue, contract liabilities	0
Contracts and grants
Revenue
Revenues	967	144
Rockefeller University | Contracts and grants
Revenue
Revenues	$ 1,000	$ 100

Income Taxes - Carryforwards (D

Income Taxes - Carryforwards (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Income Taxes
Net deferred tax liability	$ 1,613	$ 1,613

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Anti-dilutive securities
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	4,967,764	4,064,557
Stock options
Anti-dilutive securities
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	4,967,764	4,064,557

Kolltan Acquisition (Details)

Kolltan Acquisition (Details) - USD ($) $ in Millions	Jun. 20, 2022	Nov. 29, 2016
Kolltan Acquisition
Execution of the settlement agreement	$ 15
European medicines agency
Kolltan Acquisition
Business contingent amount payable	52.5
Clinical Trial
Kolltan Acquisition
Execution of the settlement agreement	15
Contractual credit merger agreement	2.5
Specified development, regulatory approvals or sales-based milestones
Kolltan Acquisition
Business contingent amount payable	$ 172.5
Kolltan | Specified development, regulatory approvals or sales-based milestones
Kolltan Acquisition
Shares issued as part of consideration (in shares)		1,217,200
Potential milestone payments		$ 172.5