Celldex Therapeutics (CLDX) 10-K 27 Feb 25 2024 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2024	Feb. 14, 2025	Jun. 30, 2024
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Document Transition Report	false
Securities Act 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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 2.4
Entity Common Stock, Shares Outstanding		66,383,811
Entity Central Index Key	0000744218
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Amendment Flag	false
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Boston, Massachusetts
Auditor Firm ID	238

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 28,356	$ 34,814
Marketable securities	696,925	388,784
Accounts and other receivables	700	2,628
Prepaid and other current assets	21,178	5,467
Total current assets	747,159	431,693
Property and equipment, net	4,346	4,060
Operating lease right-of-use assets, net	3,898	2,577
Intangible assets	27,190	27,190
Other assets	9,747	107
Total assets	792,340	465,627
Current liabilities:
Accounts payable	3,265	3,494
Accrued expenses	33,842	22,029
Current portion of operating lease liabilities	1,452	1,614
Current portion of long-term liabilities	942	3,988
Total current liabilities	39,501	31,125
Long-term portion of operating lease liabilities	2,361	928
Other long-term liabilities	3,473	4,403
Total liabilities	45,335	36,456
Commitments and contingent liabilities (Note 15)
Stockholders' equity:
Convertible preferred stock, $.01 par value; 3,000,000 shares authorized; no shares issued and outstanding at December 31, 2024 and 2023
Common stock, $.001 par value; 297,000,000 shares authorized; 66,374,549 and 55,883,377 shares issued and outstanding at December 31, 2024 and 2023, respectively	66	56
Additional paid-in capital	2,298,849	1,823,168
Accumulated other comprehensive income	3,314	3,308
Accumulated deficit	(1,555,224)	(1,397,361)
Total stockholders' equity	747,005	429,171
Total liabilities and stockholders' equity	$ 792,340	$ 465,627

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2024	Dec. 31, 2023
CONSOLIDATED BALANCE SHEETS
Convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Convertible preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Convertible preferred stock, shares issued (in shares)	0	0
Convertible preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	297,000,000	297,000,000
Common stock, shares issued (in shares)	66,374,549	55,883,377
Common stock, shares outstanding (in shares)	66,374,549	55,883,377

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues:
Total revenues	$ 7,020	$ 6,883	$ 2,357
Operating expenses:
Research and development	163,550	118,011	82,258
General and administrative	38,548	30,914	27,195
Gain on fair value remeasurement of contingent consideration			(6,862)
Litigation settlement related loss		12,500	15,000
Total operating expenses	202,098	161,425	117,591
Operating loss	(195,078)	(154,542)	(115,234)
Investment and other income, net	37,215	13,113	2,909
Net loss	$ (157,863)	$ (141,429)	$ (112,325)
Basic net loss per common share (in dollars per share)	$ (2.45)	$ (2.92)	$ (2.4)
Diluted net loss per common share (in dollars per share)	$ (2.45)	$ (2.92)	$ (2.4)
Shares used in calculating basic net loss per share (in shares)	64,395	48,449	46,888
Shares used in calculating diluted net loss per share (in shares)	64,395	48,449	46,888
Comprehensive loss:
Net loss	$ (157,863)	$ (141,429)	$ (112,325)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities	6	2,048	(634)
Comprehensive loss	(157,857)	(139,381)	(112,959)
Product development and licensing agreements
Revenues:
Total revenues	13	278	56
Contracts and grants
Revenues:
Total revenues	$ 7,007	$ 6,605	$ 2,301

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Total
Balance, beginning at Dec. 31, 2021	$ 47	$ 1,561,142	$ 1,894	$ (1,143,607)	$ 419,476
Balance, beginning (in shares) at Dec. 31, 2021	46,730,198
Increase (Decrease) in Stockholders' Equity
Shares issued under stock option and employee stock purchase plans		4,076			4,076
Shares issued under stock option and employee stock purchase plans (in shares)	470,497
Stock-based compensation		15,611			15,611
Unrealized gain (loss) on marketable securities			(634)		(634)
Net loss				(112,325)	(112,325)
Balance, ending at Dec. 31, 2022	$ 47	1,580,829	1,260	(1,255,932)	326,204
Balance, ending (in shares) at Dec. 31, 2022	47,200,695
Increase (Decrease) in Stockholders' Equity
Shares issued under stock option and employee stock purchase plans		2,236			2,236
Shares issued under stock option and employee stock purchase plans (in shares)	143,932
Shares issued in underwritten offering, net	$ 9	216,213			216,222
Shares issued in underwritten offering, net (in shares)	8,538,750
Stock-based compensation		23,890			23,890
Unrealized gain (loss) on marketable securities			2,048		2,048
Net loss				(141,429)	(141,429)
Balance, ending at Dec. 31, 2023	$ 56	1,823,168	3,308	(1,397,361)	$ 429,171
Balance, ending (in shares) at Dec. 31, 2023	55,883,377				55,883,377
Increase (Decrease) in Stockholders' Equity
Shares issued under stock option and employee stock purchase plans		9,151			$ 9,151
Shares issued under stock option and employee stock purchase plans (in shares)	693,172
Shares issued in underwritten offering, net	$ 10	432,288			432,298
Shares issued in underwritten offering, net (in shares)	9,798,000
Stock-based compensation		34,242			34,242
Unrealized gain (loss) on marketable securities			6		6
Net loss				(157,863)	(157,863)
Balance, ending at Dec. 31, 2024	$ 66	$ 2,298,849	$ 3,314	$ (1,555,224)	$ 747,005
Balance, ending (in shares) at Dec. 31, 2024	66,374,549				66,374,549

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (157,863)	$ (141,429)	$ (112,325)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	3,177	3,008	2,896
Amortization and premium of marketable securities, net	(15,749)	(6,222)	844
Loss on sale or disposal of assets	16		2
Gain on fair value remeasurement of contingent consideration			(6,862)
Stock-based compensation expense	34,242	23,890	15,611
Changes in operating assets and liabilities:
Accounts and other receivables	1,928	(2,281)	(175)
Prepaid and other current assets	(19,887)	5,900	(9,572)
Other assets	(9,640)	(3)
Accounts payable and accrued expenses	11,634	9,384	3,123
Other liabilities	(5,636)	462	2,726
Net cash used in operating activities	(157,778)	(107,291)	(103,732)
Cash flows from investing activities:
Sales and maturities of marketable securities	501,714	320,597	280,666
Purchases of marketable securities	(789,924)	(424,561)	(188,965)
Acquisition of property and equipment	(1,919)	(1,818)	(1,828)
Proceeds from sale or disposal of assets			69
Net cash (used in) provided by investing activities	(290,129)	(105,782)	89,942
Cash flows from financing activities:
Net proceeds from stock issuances	432,298	216,222
Proceeds from issuance of stock from employee benefit plans	9,151	2,236	4,076
Net cash provided by financing activities	441,449	218,458	4,076
Net increase (decrease) in cash and cash equivalents	(6,458)	5,385	(9,714)
Cash and cash equivalents at beginning of period	34,814	29,429	39,143
Cash and cash equivalents at end of period	28,356	34,814	29,429
Non-cash investing activities
Accrued construction in progress	$ 27	$ 77	$ 113

Nature of Business and Overview

Nature of Business and Overview	12 Months Ended
	Dec. 31, 2024
Nature of Business and Overview
Nature of Business and Overview	(1) Nature of Business and Overview Celldex Therapeutics, Inc. (the “Company” or “Celldex”) is a biopharmaceutical company dedicated to exploring the science of mast cell biology and developing therapeutic antibodies which have the ability to engage the human immune system and/or directly affect critical pathways to improve the lives of patients with severe inflammatory, allergic, autoimmune and other devastating diseases. Our drug candidates include monoclonal and bispecific antibodies designed to address mast cell mediated diseases for which available treatments are inadequate. The Company is primarily focusing its efforts and resources on the continued research and development of barzolvolimab (also referred to as CDX-0159) and CDX-622. At December 31, 2024, the Company had cash, cash equivalents and marketable securities of $725.3 million. The Company has had recurring losses and incurred a loss of $157.9 million for the year ended December 31, 2024. Net cash used in operations for the year ended December 31, 2024 was $157.8 million. The Company believes that the cash, cash equivalents and marketable securities at the filing date of this Form 10-K 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 18), in the event that the Company achieves the milestone related to that payment. The Company, at its option, may decide to pay that milestone payment 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, discontinue or delay our commercial manufacturing efforts, discontinue or delay our efforts to expand into additional indications for our drug product candidates, 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	(2) Summary of Significant Accounting Policies Basis of Presentation The balance sheets and statements of operations and comprehensive loss, stockholders’ equity, and cash flows, are consolidated for the years ended December 31, 2024, 2023 and 2022. These consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiary. All intercompany balances and transactions have been eliminated in consolidation. Segment Information The Company is managed as a single operating and reportable segment that operates in the business of development, manufacturing and commercialization of novel therapeutics for human health care. Our chief operating decision maker (“CODM”), the Chief Executive Officer, evaluates performance based on consolidated net loss. Other than general and administrative expenses as presented on the consolidated statement of operations, research and development expense disaggregated by program and by nature are considered to be the Company’s significant segment expenses. These results are used, in part, by our CODM in evaluating the performance of the Company by comparing budget to actual results, and to allocate resources. All revenue is derived in and long-lived assets are located in the United States. The CODM does not receive asset information other than what is presented on the consolidated balance sheets. The following table is a summary of the Company’s research and development expenses disaggregated by program. The amounts disclosed reflect direct research and development costs and an allocation of indirect research and development costs to each program. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended ​ ​ Year Ended ​ December 31, 2024 December 31, 2023 December 31, 2022 ​ ​ (In thousands) Barzolvolimab/Anti-KIT Program $ 123,750 $ 79,913 ​ $ 51,220 CDX-622 ​ 17,341 ​ 16,299 ​ 5,613 CDX-585 ​ 2,813 ​ 6,357 ​ 9,793 Other Programs (a) ​ 19,646 ​ 15,442 ​ 15,632 Total R&D Expense ​ $ 163,550 ​ $ 118,011 ​ $ 82,258 ​ (a) Other program expenses primarily include research and development expenses related to early-stage programs, revenue-generating programs and discontinued programs. The following table is a summary of the Company’s research and development expenses disaggregated by nature. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended ​ Year Ended ​ December 31, 2024 December 31, 2023 December 31, 2022 ​ ​ (In thousands) Personnel $ 51,906 $ 40,121 $ 32,674 Laboratory Supplies ​ 5,611 ​ 5,358 ​ 6,310 Facility ​ 5,094 ​ 4,970 ​ 4,764 Product Development (b) ​ 90,604 ​ 59,319 ​ 32,156 Other Expenses (c) ​ 10,335 ​ 8,243 ​ 6,354 Total R&D Expense ​ $ 163,550 ​ $ 118,011 ​ $ 82,258 ​ (b) Product development expenses include clinical investigator site fees, external trial monitoring costs, data accumulation costs, contracted research and outside clinical drug product manufacturing. (c) Other expenses primarily include research and development consulting, insurance, licensing and software expenses. Use of Estimates The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and use assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with a maturity date of 90 days or less at the date of purchase to be cash equivalents. Cash equivalents consist principally of money market funds and debt securities. Marketable Securities The Company invests its excess cash balances in marketable securities, including municipal bond securities, U.S. government agency securities, and highly rated corporate bonds. The Company classifies all of its marketable securities as current assets on the balance sheets because they are available-for-sale and available to fund current operations. Marketable securities are stated at fair value with unrealized gains and losses included as a component of accumulated other comprehensive income (loss), which is a separate component of stockholders’ equity. Each reporting period, the Company evaluates its investment portfolio to determine if any security is impaired and if an allowance for credit losses should be recorded. As part of this evaluation, the Company considers whether it has the ability and intent to hold the investment until recovery of its amortized cost basis and whether the decline in fair value is due to any credit related factors. If an impairment is the result of a credit loss, the Company recognizes an allowance for credit losses. Realized gains and losses are determined on the specific identification method and are included in investment and other income, net. Concentration of Credit Risk and of Significant Customers and Suppliers Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents, marketable securities and accounts receivable. The Company invests its cash, cash equivalents and marketable securities in debt instruments and interest-bearing accounts at major financial institutions in excess of insured limits. The Company mitigates credit risk by limiting the investment type and maturity to securities that preserve capital, maintain liquidity and have a high credit quality. The Company has not historically experienced credit losses from its accounts receivable and therefore has not established an allowance for doubtful accounts. Revenue from Rockefeller University represented 100%, 95% and 75% of total Company revenue for the years ended December 31, 2024, 2023 and 2022, respectively. The Company relies on contract development & manufacturing organizations (CDMOs) to manufacture drug substance and drug product as well as for future commercial supplies. The Company also relies on CDMOs for supply of raw materials as well as filling, packaging, storing and shipping our drug products. Fair Value Measurements The Company has certain assets and liabilities that are measured at fair value in the financial statements. The Company seeks to maximize the use of observable inputs (market data obtained from sources independent from the Company) and to minimize the use of unobservable inputs (the Company’s assumptions about how market participants would price assets and liabilities) when measuring the fair value of its assets and liabilities. These assets and liabilities are classified into one of three levels of the following fair value hierarchy as defined by U.S. GAAP: Level 1: Observable inputs such as quoted prices in active markets for identical assets or liabilities. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2: Observable inputs other than Level 1 prices, such as quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active. Level 3: Unobservable inputs based on the Company’s assessment of the assumptions that market participants would use in pricing the asset or liability. Property and Equipment Property and equipment are stated at cost and depreciated over the estimated useful lives of the related assets using the straight-line method. Laboratory seven The treatment of costs to construct property and equipment depends on the nature of the costs and the stage of construction. Costs incurred in the project planning, design, construction and installation phases are capitalized as part of the cost of the asset. The Company stops capitalizing these costs when the asset is substantially complete and ready for its intended use. For manufacturing property and equipment, the Company also capitalizes the cost of validating these assets for the underlying manufacturing process. The Company completes the capitalization of validation costs when the asset is substantially complete and ready for its intended use. Costs capitalized include incremental labor and fringe benefits, and direct consultancy services. Leases The Company has operating leases of office, manufacturing and laboratory space, which have remaining lease terms of one The Company determines if an arrangement contains a lease at inception. Operating lease right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Certain adjustments to the right-of-use asset may be required for items such as prepaid or accrued lease payments, initial direct costs paid or incentives received. The Company’s leases do not contain an implicit rate, and therefore the Company uses an estimated incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. Options to extend or terminate the lease are reflected in the calculation when it is reasonably certain that the option will be exercised. The Company has elected to account for lease and non-lease components as a single lease component, however non-lease components that are variable, such as common area maintenance and utilities, are generally paid separately from rent based on actual costs incurred and therefore are not included in the right-of-use asset and operating lease liability and are reflected as an expense in the period incurred. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Contingent Consideration The Company records contingent consideration resulting from a business combination at its fair value on the acquisition date. The Company determines the fair value of the contingent consideration based primarily on the (i) timing and probability of success of clinical events or regulatory approvals; (ii) timing and probability of success of meeting clinical and commercial milestones; and (iii) discount rates. The Company’s contingent consideration liabilities arose in connection with its acquisition of Kolltan. On a quarterly basis, the Company revalues these obligations and records increases or decreases in their fair value as an adjustment to operating earnings. Changes to contingent consideration obligations can result from adjustments to discount rates, accretion of the discount rates due to the passage of time, changes in the Company’s estimates of the likelihood or timing of achieving development or commercial milestones, changes in the probability of certain clinical events or changes in the assumed probability associated with regulatory approval. The assumptions related to determining the 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. Intangible Assets IPR&D assets acquired in a business combination initially are recorded at fair value and accounted for as indefinite-lived intangible assets. The valuation model used to measure the fair value of the Company’s IPR&D assets was primarily a discounted cash flow approach. The assumptions used in determining the fair value of the Company’s IPR&D assets include (i) probability of success; (ii) probability of partnership; (iii) partnership milestones; and (iv) discount rate. These assets are capitalized on the Company’s balance sheets until either the project underlying them is completed or the assets become impaired. If a project is completed, the carrying value of the related intangible asset is amortized over the remaining estimated life of the asset beginning in the period in which the project is completed. If a project becomes impaired or is abandoned, the carrying value of the related intangible asset is written down to its fair value and an impairment charge is taken in the period in which the impairment occurs. Each IPR&D asset is assessed for impairment at least annually or when impairment indicators are present. The Company has the option to assess qualitative factors to determine if it is more likely than not that the IPR&D asset is impaired and whether it is necessary to perform a quantitative impairment test. Impairment of Intangible and Long-Lived Assets The Company evaluates the recoverability of its long-lived assets, including property and equipment, right-of-use assets, and intangible assets when circumstances indicate that an event of impairment may have occurred. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values. Revenue Recognition Revenues are recognized when performance obligations under agreements or contracts are satisfied, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. The Company determines revenue recognition through the following steps: ● Identification of the contract, or contracts, with a customer; ● Identification of the performance obligations in the contract; ● Determination of the transaction price; ● Allocation of the transaction price to the performance obligations in the contract; and ● Recognition of revenue when, or as, the Company satisfies a performance obligation. Revenue for the Company is derived from product development agreements with collaborative partners for the research and development of therapeutic drug candidates. The terms of the agreements may include nonrefundable signing and licensing fees, funding for research, development and manufacturing, milestone payments and royalties on any product sales derived from collaborations. The Company assesses the multiple obligations typically within product development contracts to determine the distinct performance obligations and how to allocate the arrangement consideration to each distinct performance obligation. Under product development agreements, revenue is generally recognized using a cost-to-cost measure of progress. Revenue is recognized based on the costs incurred to date as a percentage of the total estimated costs to fulfill the contract. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Due to the nature of the work performed in these arrangements, the estimation of cost at completion is complex, subject to many variables, such as expected clinical trial costs, and requires significant judgements. Circumstances can arise that change original estimates of costs or progress toward completion. Any revisions to estimates are reflected in revenue on a cumulative catch-up basis in the period in which the change in circumstances became known. Revenue for the Company is also derived from manufacturing and research and development arrangements. The Company operates a cGMP manufacturing facility in Fall River, Massachusetts, to produce drug substance for its current and planned early-stage clinical trials. In order to utilize excess capacity, the Company has, from time to time, entered into contract manufacturing and research and development arrangements in which services are provided on a time-and-material basis or at a negotiated fixed price. Revenue from time-and-material contracts is generally recognized on an output basis as labor hours and/or direct expenses are incurred. Under fixed-price contracts, revenue is generally recognized on an output basis as progress is made toward completion of the performance obligations using surveys of performance completed to date. Contract Assets and Liabilities The Company classifies the right to consideration in exchange for products or services transferred to a client as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional as compared to a contract asset which is a right to consideration that is conditional upon factors other than the passage of time. The Company’s contract liabilities result from arrangements where the Company has received payment in advance of performance under the contract. These amounts are included as deferred revenue within current portion of long-term liabilities on the consolidated balance sheets. Research and Development Expenses Research and development costs, including internal and contract research costs, are expensed as incurred. Research and development expenses consist mainly of clinical trial costs, manufacturing of clinical material, toxicology and other preclinical studies, personnel costs, depreciation, license fees and funding of outside contracted research. Clinical trial expenses include expenses associated with clinical research organization, or CRO, services. Contract manufacturing expenses include expenses associated with contract development & manufacturing organization, or CDMO, services. The invoicing from CROs and CDMOs for services rendered can lag several months. The Company accrues the cost of services rendered in connection with CRO and CDMO activities based on our estimate of costs incurred. The Company maintains regular communication with our CROs and CDMOs to assess the reasonableness of its estimates. Differences between actual expenses and estimated expenses recorded have not been material and are adjusted for in the period in which they become known. Patent Costs Patent costs are expensed to general and administrative expense as incurred. Certain patent costs are reimbursed by the Company’s product development and licensing partners. Any reimbursed patent costs are recorded as product development and licensing agreement revenues in the Company’s consolidated financial statements. Stock-Based Compensation The Company records stock-based compensation expense for all stock-based awards made to employees, consultants and non-employee directors based on the estimated fair values of the stock-based awards expected to vest at the grant date and adjusts, if necessary, to reflect actual forfeitures. Compensation expense for all stock-based awards is recognized using the straight-line method over the term of vesting or performance. Foreign Currency Translation Net unrealized gains and losses resulting from foreign currency translation are included in accumulated other comprehensive income. At December 31, 2024 and 2023, accumulated other comprehensive income includes a net unrealized gain related to foreign currency translation of $2.6 million. Income Taxes The Company uses the asset and liability method to account for income taxes, including the recognition of deferred tax assets and deferred tax liabilities for the anticipated future tax consequences attributable to differences between financial statement amounts and their respective tax basis. Quarterly, the Company reviews its deferred tax assets for recovery. A valuation allowance is established when the Company believes that it is more likely than not that its deferred tax assets will not be realized. Changes in valuation allowances from period to period are included in the Company’s tax provision in the period of change. The Company records uncertain tax positions in the financial statements only if it is more likely than not that the uncertain tax position will be sustained upon examination by the taxing authorities. The Company records interest and penalties related to uncertain tax positions in income tax expense. Comprehensive Loss Comprehensive loss is comprised of net loss and certain changes in stockholders’ equity that are excluded from net loss. The Company includes foreign currency translation adjustments and unrealized gains and losses on marketable securities in other comprehensive loss. The statements of operations and comprehensive loss reflect total comprehensive loss for the years ended December 31, 2024, 2023 and 2022. 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2024 2023 2022 Stock ​ 7,540,109 ​ 6,378,924 ​ 5,085,662 ​ Newly-Adopted Accounting Pronouncements In November 2023, the FASB issued ASU 2023-07 Segment Reporting - Improvements to Reportable Segment Disclosures Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the adoption of recently issued standards that are not yet effective will not have a material impact on the Company’s consolidated financial statements or disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, In March 2024, the SEC adopted final rules requiring public entities to provide certain climate-related information in their registration statements and annual reports. The rules require disclosure of, among other things: material climate-related risks; activities to mitigate or adapt to such risks; governance and management of such risks; and material greenhouse gas (GHG) emissions from operations owned or controlled (Scope 1) and/or indirect emissions from purchased energy consumed in operations (Scope 2). Additionally, the rules require disclosure in the notes to the financial statements of the effects of severe weather events and other natural conditions, subject to certain materiality thresholds. In April 2024, the SEC voluntarily stayed the new rules as a result of pending legal challenges. Absent the result of pending legal challenges, and the removal of the stay, the rules were to become effective on a phased-in timeline, with the first requirements to be adopted for the Company’s fiscal year beginning in 2025. The Company is assessing the effect of the new rules on its consolidated financial statements and related disclosures.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2024
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income	(3) Accumulated Other Comprehensive Income The changes in accumulated other comprehensive income, which is reported as a component of stockholders’ equity, for the year ended December 31, 2024 are summarized below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized ​ ​ ​ ​ ​ ​ Gain (Loss) on ​ ​ ​ ​ ​ ​ ​ ​ Marketable ​ Foreign ​ ​ ​ ​ ​ Securities ​ Currency Items ​ Total ​ ​ (In thousands) Balance at December 31, 2023 ​ $ 712 ​ $ 2,596 ​ $ 3,308 Other comprehensive gain ​ ​ 6 ​ ​ — ​ ​ 6 Balance at December 31, 2024 ​ $ 718 ​ $ 2,596 ​ $ 3,314 ​ No amounts were reclassified out of accumulated other comprehensive income during the years ended December 31, 2024, 2023 and 2022.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2024
Fair Value Measurements
Fair Value Measurements	(4) Fair Value Measurements The following tables set forth the Company’s financial assets and liabilities subject to fair value measurements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ December 31, 2024 ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 9,927 — ​ $ 9,927 ​ — Marketable securities ​ ​ 696,925 — ​ ​ 696,925 ​ — ​ ​ $ 706,852 ​ — ​ $ 706,852 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 19,803 — ​ $ 19,803 ​ — Marketable securities ​ ​ 388,784 — ​ ​ 388,784 ​ — ​ ​ $ 408,587 ​ — ​ $ 408,587 ​ ​ — ​ The Company’s financial assets consist mainly of 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 December 31, 2024 and December 31, 2023. 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 payment are met. During the year ended December 31, 2022, the Company recorded a $6.9 million gain on fair value remeasurement of contingent consideration primarily due to the Company’s decision to deprioritize the CDX-1140 program. The assumptions related to determining the 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 of assets or liabilities between the fair value measurement classifications during the years ended December 31, 2024 and 2023.

Marketable Securities

Marketable Securities	12 Months Ended
	Dec. 31, 2024
Marketable Securities
Marketable Securities	(5) Marketable Securities The following is a summary of marketable debt securities, classified as available-for-sale: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair ​ ​ Cost ​ Gains ​ Losses ​ Value ​ ​ (In thousands) December 31, 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 185,388 ​ $ 467 ​ $ — ​ $ 185,855 Maturing after one year through three years ​ ​ 102,331 ​ ​ 316 ​ ​ (144) ​ ​ 102,503 Total U.S. government and municipal obligations ​ $ 287,719 ​ $ 783 ​ $ (144) ​ $ 288,358 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 336,350 ​ $ 350 ​ $ (54) ​ $ 336,646 Maturing after one year through three years ​ ​ 72,139 ​ ​ 36 ​ ​ (254) ​ ​ 71,921 Total corporate debt securities ​ $ 408,489 ​ $ 386 ​ $ (308) ​ $ 408,567 Total marketable securities ​ $ 696,208 ​ $ 1,169 ​ $ (452) ​ $ 696,925 December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 132,459 ​ $ 143 ​ $ (53) ​ $ 132,549 Maturing after one year through three years ​ ​ 26,009 ​ ​ 77 ​ ​ — ​ ​ 26,086 Total U.S. government and municipal obligations ​ $ 158,468 ​ $ 220 ​ $ (53) ​ $ 158,635 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 183,625 ​ $ 300 ​ $ (10) ​ $ 183,915 Maturing after one year through three years ​ ​ 45,977 ​ ​ 257 ​ ​ — ​ ​ 46,234 Total corporate debt securities ​ $ 229,602 ​ $ 557 ​ $ (10) ​ $ 230,149 Total marketable securities ​ $ 388,070 ​ $ 777 ​ $ (63) ​ $ 388,784 ​ The Company holds investment grade marketable securities. Unrealized losses are generally attributable to changes in interest rates. The aggregate fair value of marketable securities held by the Company in an unrealized loss position as of December 31, 2024 and December 31, 2023 was $142.5 million and $80.4 million, respectively. The Company has the intent and ability to hold its marketable securities until recovery and has determined that there has been no material change to the Company’s credit risk. As a result, the Company determined it did not hold any investments with a credit loss at December 31, 2024. Marketable securities include $6.1 million and $1.9 million in accrued interest at December 31, 2024 and 2023, respectively.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2024
Property and Equipment, Net
Property and Equipment, Net	(6) Property and Equipment, Net Property and Equipment, net includes the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Laboratory equipment ​ $ 10,411 ​ $ 9,848 Manufacturing equipment ​ 3,010 ​ 2,419 Office furniture and equipment ​ 3,965 ​ 3,738 Leasehold improvements ​ 10,285 ​ 9,653 Construction in progress ​ 139 ​ 787 Total property and equipment ​ 27,810 ​ 26,445 Less: accumulated depreciation and amortization ​ (23,464) ​ (22,385) Property and equipment, net ​ $ 4,346 ​ $ 4,060 ​ Depreciation and amortization expense related to property and equipment was $1.6 million, $1.5 million and $1.4 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Leases

Leases	12 Months Ended
	Dec. 31, 2024
Leases
Leases	(7) Leases The Company has operating leases of office, manufacturing and laboratory space, which have remaining lease terms of one During the years ended December 31, 2024, 2023 and 2022, the Company recorded right of use assets lease liabilities million Operating lease expense was $2.0 million, $1.9 million and $1.9 million for years ended December 31, 2024, 2023 and 2022, respectively. Variable lease expense was $0.8 million, $0.8 million and $0.8 million for years ended December 31, 2024, 2023 and 2022, respectively. Cash paid for amounts included in the measurement of operating lease liabilities was $2.0 million, $2.0 million and $1.9 million for the years ended December 31, 2024, 2023 and 2022, respectively. As of December 31, 2024, the weighted-average remaining lease term was 2 years and the weighted-average discount rate was 10.0%, compared to a weighted-average remaining lease term of 2 years and weighted average discount rate of 10.0% as of December 31, 2023. Future minimum lease payments under non-cancellable leases as of December 31, 2024 were as follows: ​ ​ ​ ​ 2025 $ 1,761 2026 ​ ​ 1,779 2027 ​ 742 Total lease payments ​ 4,282 Less imputed interest ​ (469) Present value of operating lease liabilities ​ $ 3,813 ​

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2024
Intangible Assets
Intangible Assets	(8) Intangible Assets At December 31, 2024 and 2023, the carrying value of the Company’s indefinite-lived intangible assets was $27.2 million. Indefinite-lived intangible assets consist of acquired in-process research and development (“IPR&D”) related to the development of the anti-KIT program (including barzolvolimab). Barzolvolimab is in Phase 3 development. As of December 31, 2024, 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. The Company performed its annual impairment test of the IPR&D asset related to the development of the anti-KIT program (including barzolvolimab) during the fourth quarter of 2024 and concluded that the IPR&D asset was not 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 Assets

Other Assets	12 Months Ended
	Dec. 31, 2024
Other Assets
Other Assets	(9) Other Assets The Company records advance payments for services that will not be performed within one year of the balance sheet date as other assets. Such amounts will be recognized as expense in the period in which the related services are performed. Advance payments reflected within other assets in our consolidated balance sheets were $9.6 million and $0.0 million at December 31, 2024 and December 31, 2023, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2024
Accrued Expenses
Accrued Expenses	(10) Accrued Expenses Accrued expenses include the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Accrued payroll and employee benefits ​ $ 11,568 ​ $ 9,348 Accrued research and development contract costs ​ ​ 20,544 ​ ​ 10,864 Accrued professional fees ​ ​ 1,392 ​ ​ 1,439 Other accrued expenses ​ ​ 338 ​ ​ 378 ​ ​ $ 33,842 ​ $ 22,029 ​

Other Long-Term Liabilities

Other Long-Term Liabilities	12 Months Ended
	Dec. 31, 2024
Other Long-Term Liabilities
Other Long-Term Liabilities	(11) Other Long-Term Liabilities Other long-term liabilities include the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Net deferred tax liabilities related to IPR&D (Note 16) ​ $ 1,613 ​ $ 1,613 Deferred income from sale of tax benefits ​ ​ 2,790 ​ ​ 3,720 Deferred revenue (Note 14) ​ ​ 12 ​ ​ 3,058 Total ​ ​ 4,415 ​ ​ 8,391 Less current portion ​ ​ (942) ​ ​ (3,988) Long-term portion ​ $ 3,473 ​ $ 4,403 ​ 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 years ended December 31, 2024 and 2023.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2024
Stockholders' Equity
Stockholders' Equity	(12) Stockholders’ Equity Common Stock In November 2023, the Company filed an automatic shelf registration statement with the SEC to register for sale any combination of the types of securities described in the shelf registration statement, including shares of its common stock. Also in November 2023, the Company issued 8,538,750 shares of its common stock in an underwritten public offering resulting in net proceeds to the Company of $216.2 million, after deducting underwriting fees and offering expenses. On February 26, 2024, the Company entered into a controlled equity offering sales agreement (“ATM 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 December 31, 2024, the Company had registered $300.0 million of its common stock to be sold pursuant to the Company’s ATM Agreement, all of which remained unsold as of that date. In March 2024, the Company issued 9,798,000 shares of its common stock in an underwritten public offering resulting in net proceeds to the Company of $432.3 million, after deducting underwriting fees and offering expenses. Convertible Preferred Stock At December 31, 2024, the Company had authorized 3,000,000 shares of preferred stock all of which have been designated Class C Preferred Stock including 350,000 shares which have been designated Series C-1 Junior Participating Cumulative Preferred Stock (the “Series C-1 Preferred Stock”). No shares of Series C-1 Preferred Stock were outstanding at December 31, 2024 or 2023.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2024
Stock-Based Compensation
Stock-Based Compensation	(13) Stock-Based Compensation The Company has the following stock-based compensation plans: the 2004 Employee Stock Purchase Plan (the “2004 ESPP Plan”), the 2008 Stock Option and Incentive Plan (the “2008 Plan”) and the 2021 Omnibus Equity Incentive Plan (the “2021 Plan”). There are no shares available for future grant under the 2008 Plan. Outstanding options under the 2008 Plan will be rolled into the 2021 Plan if canceled. Employee Stock Purchase Plan At December 31, 2024, a total of 276,666 shares of common stock are reserved for issuance under the 2004 ESPP Plan. Under the 2004 ESPP Plan, each participating employee may purchase shares of common stock through payroll deductions at a purchase price equal to 85% of the lower of the fair market value of the common stock at either the beginning of the offering period or the applicable exercise date. During the years ended December 31, 2024, 2023 and 2022, the Company issued 13,187, 12,729 and 12,243 shares under the 2004 ESPP Plan, respectively. At December 31, 2024, 150,316 shares were available for issuance under the 2004 ESPP Plan. Employee Stock Option Plan The 2021 Plan permits the granting of incentive stock options (intended to qualify as such under Section 422A of the Internal Revenue Code of 1986, as amended), non-qualified stock options, stock appreciation rights, performance share units, restricted stock and other awards of restricted stock to employees, consultants and non-employee directors. The 2021 Plan allows for grants of new awards until April 19, 2031. As of December 31, 2024, there were 1,513,850 shares outstanding under the 2008 Plan that will be rolled into the 2021 Plan if canceled. The Company’s Board of Directors determines the term of each option, option price, and number of shares for which each option is granted and the rate at which each option vests. Options generally vest over a period not to exceed four years. The term of each option cannot exceed ten years (five years for options granted to holders of more than 10% of the voting stock of the Company), and the exercise price of stock options cannot be less than the fair market value of the common stock at the date of grant (110% of fair market value for incentive stock options granted to holders of more than 10% of the voting stock of the Company). Vesting of all employee and non-employee director stock option awards may accelerate upon a change in control as defined in the 2021 Plan. A summary of stock option activity for the year ended December 31, 2024 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Weighted ​ ​ ​ ​ Average ​ Average ​ ​ ​ ​ Exercise ​ Remaining ​ ​ ​ ​ Price ​ Contractual ​ ​ Shares ​ Per Share ​ Term (In Years) Options outstanding at December 31, 2023 ​ 6,378,924 ​ $ 29.69 ​ 7.5 Granted ​ 1,959,320 ​ $ 36.22 ​ — Exercised ​ (679,985) ​ $ 12.98 ​ — Canceled ​ (118,150) ​ $ 120.67 ​ — Options outstanding at December 31, 2024 ​ 7,540,109 ​ $ 31.47 ​ 7.5 Options vested and expected to vest at December 31, 2024 ​ 7,416,025 ​ $ 31.41 ​ 7.4 Options exercisable at December 31, 2024 ​ 3,980,565 ​ $ 29.17 ​ 6.3 Shares available for grant under the Celldex Therapeutics, Inc. 2021 Omnibus Equity Incentive Plan (as amended, effective as of June 13, 2024) at December 31, 2024 ​ 2,372,333 ​ ​ — ​ — ​ The total intrinsic value of stock options exercised during the years ended December 31, 2024, 2023 and 2022 was $17.2 million, $2.7 million and $12.8 million, respectively. The weighted average grant-date fair value of stock options granted during the years ended December 31, 2024, 2023 and 2022 was $26.21, $28.15 and $17.60, respectively. The total fair value of stock options vested during the years ended December 31, 2024, 2023 and 2022 was $32.4 million, $20.4 million and $15.6 million, respectively. The aggregate intrinsic value of stock options outstanding at December 31, 2024 was $24.4 million. The aggregate intrinsic value of stock options vested and expected to vest at December 31, 2024 was $24.4 million. The aggregate intrinsic value of stock options exercisable at December 31, 2024 was $23.0 million. As of December 31, 2024, total compensation cost related to non-vested employee and non-employee director stock options not yet recognized was approximately $77.1 million, net of estimated forfeitures, which is expected to be recognized as expense over a weighted average period of 2.6 years. Valuation and Expenses Information Stock-based compensation expense for the years ended December 31, 2024, 2023 and 2022 was recorded as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 ​ ​ (In thousands) Research and development ​ $ 17,442 ​ $ 11,948 ​ $ 8,082 General and administrative ​ ​ 16,800 ​ ​ 11,942 ​ ​ 7,529 Total stock-based compensation expense ​ $ 34,242 ​ $ 23,890 ​ $ 15,611 ​ The fair values of employee and director stock options granted during the years ended December 31, 2024, 2023 and 2022 were valued using the Black-Scholes option pricing model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 Expected stock price volatility ​ 82 - 93% ​ 92% ​ 90 - 97% Expected option term ​ 6.0 Years ​ 6.0 Years ​ 6.0 Years Risk-free interest rate ​ 3.5 - 4.5% ​ 3.5 - 4.7% ​ 1.7 - 4.2% Expected dividend yield ​ None ​ None ​ None ​ The Company estimates expected term based on historical exercise patterns. The Company uses its historical stock price volatility consistent with the expected term of grant as the basis for its expected volatility assumption. The risk-free interest rate is based upon the yield of U.S. Treasury securities consistent with the expected term of the option. The dividend yield assumption is based on the Company’s history of zero dividend payouts and expectation that no dividends will be paid in the foreseeable future.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2024
Revenue
Revenue	(14) Revenue Contract and Grants Revenue The Company has entered into agreements with Rockefeller University (“Rockefeller”) 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 $7.0 million, $6.6 million and $1.8 million in revenue under the agreements with Rockefeller during the years ended December 31, 2024, 2023 and 2022, respectively. Contract Assets and Liabilities At December 31, 2024 and 2023, the Company’s right to consideration under all contracts was considered unconditional, and as such, there were no recorded contract assets. At December 31, 2024, the Company had no material contract liabilities recorded. At December 31, 2023, the Company had $3.1 million in contract liabilities recorded. Revenue recognized from contract liabilities as of December 31, 2023 during the year ended December 31, 2024 was $3.1 million.

Collaboration Agreements

Collaboration Agreements	12 Months Ended
	Dec. 31, 2024
Collaboration Agreements
Collaboration Agreements	(15) Collaboration Agreements The Company has entered into license agreements whereby the Company has received licenses or options to license technology, specified patents and/or patent applications. These license and collaboration agreements generally provide for royalty payments equal to specified percentages of product sales, annual license maintenance fees, continuing patent prosecution costs and potential future milestone payments to third parties upon the achievement of certain development, regulatory and/or commercial milestones. Nonrefundable license fee expense of $0.2 million, $0.3 million and $0.1 million was recorded to research and development expense for the years ended December 31, 2024, 2023 and 2022, respectively. Yale University (Yale) Under a license agreement with Yale, the Company may be required to make a one-time payment to Yale of $3.0 million with respect to barzolvolimab upon achievement of a specified commercial milestone. In addition, the Company may be required to pay a low single-digit royalty on annual worldwide net sales of barzolvolimab. Unless earlier terminated by us or Yale, the Yale license agreement is due to expire no later than May 2038 but may expire earlier on a country-by-country basis under specified circumstances.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2024
Income Taxes
Income Taxes	(16) Income Taxes The components of income tax benefit (provision) are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2024 2023 2022 ​ ​ (In thousands) Income tax benefit (provision): ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 39,821 ​ $ 36,067 ​ $ 17,484 State ​ ​ 15,375 ​ ​ 13,691 ​ ​ 9,606 Expiration of NOLs and R&D credit ​ ​ (82,825) ​ ​ (15,141) ​ ​ (16,862) ​ ​ ​ (27,629) ​ ​ 34,617 ​ ​ 10,228 Deferred tax valuation allowance ​ ​ 27,629 ​ ​ (34,617) ​ ​ (10,228) ​ ​ $ — ​ $ — ​ $ — ​ A reconciliation between the amount of reported income tax and the amount computed using the U.S. statutory rate is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 ​ ​ (In thousands) Pre-tax loss ​ $ (157,863) ​ $ (141,429) ​ $ (112,325) Loss at statutory rates ​ ​ (33,151) ​ ​ (29,700) ​ ​ (23,588) Research and development credits ​ ​ (7,332) ​ ​ (5,237) ​ ​ (3,876) State taxes ​ ​ (15,375) ​ ​ (13,691) ​ ​ (9,606) Other ​ ​ 662 ​ ​ (1,130) ​ ​ 11,421 Change in fair value remeasurement of contingent consideration ​ ​ — ​ ​ — ​ ​ (1,441) Expiration of Federal and State NOLs and R&D credits ​ ​ 82,825 ​ ​ 15,141 ​ ​ 16,862 Change in valuation allowance ​ ​ (27,629) ​ ​ 34,617 ​ ​ 10,228 Income tax (benefit) provision ​ $ — ​ $ — ​ $ — ​ Deferred tax assets and liabilities are recognized based on temporary differences between the financial reporting and tax basis of assets and liabilities using future expected enacted rates. The principal components of the deferred tax assets and liabilities at December 31, 2024 and 2023 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Gross deferred tax assets ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 176,816 ​ $ 197,618 Tax credit carryforwards ​ ​ 24,718 ​ ​ 56,830 Deferred research and development expenses ​ ​ 101,047 ​ ​ 82,077 Stock-based compensation ​ ​ 20,940 ​ ​ 14,671 Fixed assets ​ ​ 1,033 ​ ​ 1,019 Accrued expenses and other ​ ​ 429 ​ ​ 398 ​ ​ ​ 324,983 ​ ​ 352,613 Gross deferred tax liabilities ​ ​ ​ ​ ​ ​ IPR&D intangibles ​ ​ (6,840) ​ ​ (6,840) Total deferred tax assets and liabilities ​ ​ 318,143 ​ ​ 345,773 Valuation allowance ​ ​ (319,756) ​ ​ (347,386) Net deferred tax liability ​ $ (1,613) ​ $ (1,613) ​ 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. The net deferred tax liability of $1.6 million at December 31, 2024 and 2023, relates to the temporary differences associated with the IPR&D intangible assets acquired in previous business combinations and are not deductible for tax purposes. As of December 31, 2024, the Company had federal and state net operating loss carryforwards of $566.0 million and $888.8 million, respectively, which may be available to offset certain future income tax liabilities. State net operating loss carryforwards begin to expire in 2024. The federal net operating loss carryforwards of $566.0 million are from 2005 through 2024 and begin to expire in 2024. As of December 31, 2024, the Company also had federal and state research and development tax credit carryforwards of $19.8 million and $6.3 million, respectively, which may be available to offset future income tax liabilities and begin to expire in 2040 and 2029, respectively. Utilization of the net operating loss carryforwards and research and credit carryforwards may be subject to a substantial annual limitation under Section 382 of the Internal Revenue Code of 1986, or Section 382, due to ownership changes that occurred previously or that could occur in the future. These ownership changes may limit the amount of carryforwards that can be utilized annually to offset future taxable income. In general, an ownership change, as defined by Section 382, results from transactions increasing the ownership of certain shareholders or public groups in the stock of a corporation by more than 50% over a three-year period. The Company has performed a study under Internal Revenue Code Section 382 as of June 30, 2024, and concluded that a change in ownership following stock issuances in 2016 and 2020 triggered Section 382 limitations and approximately $758.7 million of federal NOL carryforwards and $48.7 million of federal tax credit carryforwards that were generated through June 30, 2020 will expire unutilized due to Section 382 and 383 limitations. The Company also estimated the amounts of State net operating loss and research and development tax credit carryforwards which will expire unutilized as a result of its annual limitations under Section 382 and has excluded those amounts from the carryforward amounts disclosed above and in the deferred tax assets and liabilities table included in this footnote. As of December 31, 2024 and 2023, the Company did not have any unrecognized tax benefits. 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. Generally, in U.S. federal and state taxing jurisdictions, all years which generated net operating losses and/or tax credit carryforwards remain subject to examination to the extent those carryforwards are utilized in a subsequent period.

Retirement Savings Plan

Retirement Savings Plan	12 Months Ended
	Dec. 31, 2024
Retirement Savings Plan
Retirement Savings Plan	(17) Retirement Savings Plan The Company maintains a 401(k) Plan which is available to substantially all employees. Under the terms of the 401(k) Plan, participants may elect to contribute up to 60% of their compensation or the statutory prescribed limits. The Company may make 50% matching contributions on up to 4% of a participant’s annual salary. Benefit expense for the 401(k) Plan was $0.5 million, $0.5 million and $0.4 million for the years ended December 31, 2024, 2023 and 2022, respectively.

Kolltan Acquisition

Kolltan Acquisition	12 Months Ended
	Dec. 31, 2024
Kolltan Acquisition
Kolltan Acquisition	(18) 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 July 15, 2022, the Company entered into a definitive settlement agreement between the Company and SRS (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 Settlement Agreement, all milestone payments provided for by the Merger Agreement were 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 paid $12.5 million upon the Successful Completion (as defined in the Settlement Agreement) of a Phase 2 Clinical Trial (as defined in the Merger Agreement) of barzolvolimab. (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 in the Settlement Agreement). 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 in July 2022. The Company paid the second milestone for “successful completion” of a Phase 2 Clinical Trial of barzolvolimab in cash in November 2023. A future milestone payment related to the barzolvolimab 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. A future milestone payment related to the remaining Surviving Company Products is measured at fair value (refer to Note 4). When and if the remaining payment described above becomes due, it 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.

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Cybersecurity Risk Management a

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Cybersecurity Risk Management and Strategy To effectively prevent, detect and respond to cybersecurity threats, we maintain a cyber risk management program under the responsibility of the head of the Information Technology (“IT”) function. Our IT head has more than 25 years of IT experience in the biopharmaceutical industry where she has been responsible for technology leadership and digital transformation across core operations. Management and administration of cybersecurity systems and activities are primarily outsourced to consultants who have cross-functional expertise in cyber security and who perform the work under the supervision of the IT head. Our IT head, in turn reports to the Senior Vice-President and General Counsel who is responsible for and knowledgeable of legal and contractual cybersecurity risk for the organization. The program is comprised of policies, standards, architecture, and processes, which are reviewed and updated on a periodic basis. The program leverages a multilayered approach of utilizing different practices, technologies, vendors or techniques without an overreliance on a single vendor. We engage with consultants to help develop and evidence the policies, standards, and processes in a manner consistent with applicable legal requirements, and also evaluate and adopt cybersecurity software from reputable vendors in cybersecurity, some that provide software as a service solutions backed by a Security Operations Center. We also engage separate third parties to provide penetration testing, risk consulting, cybersecurity incident assessment and forensics, as necessary and in addition to IT’s internal risk assessment processes. We work with many companies that provide hosted software or support for software systems. It is important for these companies to also have effective cybersecurity measures to protect data and systems. We have a self-attestation form to assess cybersecurity readiness that is sent to select vendors based on a risk assessment. For certain vendors, we request System and Organization Controls (SOC) reports or similar documents to provide assurance that the vendors have audited practices or practices in keeping with our legal requirements even if SOC audit documentation does not exist. We have also engaged legal counsel to advise on cybersecurity matters and we have developed an escalation protocol to report cybersecurity incidents as legally required. No material cybersecurity incidents have occurred to date. The program also includes training that reinforces our policies, standards, and practices, as well as the expectation that employees comply with these policies. The training engages personnel on how to identify potential cybersecurity risks and protect our resources and information. This training is mandatory for all employees on a periodic basis, and it is supplemented by testing initiatives, including periodic phishing tests. We maintain a cybersecurity risk insurance policy.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	To effectively prevent, detect and respond to cybersecurity threats, we maintain a cyber risk management program under the responsibility of the head of the Information Technology (“IT”) function. Our IT head has more than 25 years of IT experience in the biopharmaceutical industry where she has been responsible for technology leadership and digital transformation across core operations. Management and administration of cybersecurity systems and activities are primarily outsourced to consultants who have cross-functional expertise in cyber security and who perform the work under the supervision of the IT head.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Governance; Board Oversight Our Audit Committee is responsible for reviewing our information security programs, including cybersecurity. Our IT team provides regular updates to the Audit Committee on our IT security strategy, secure score assessments, penetration testing results, and status of risk mitigation activities, where applicable. Our IT team also notifies the Audit Committee and Executive Committee of any cybersecurity incidents (suspected or actual) and provides updates on the incidents as well as cybersecurity risk mitigation activities, as appropriate.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Audit Committee
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	IT team provides regular updates to the Audit Committee on our IT security strategy, secure score assessments, penetration testing results, and status of risk mitigation activities, where applicable. Our IT team also notifies the Audit Committee and Executive Committee of any cybersecurity incidents (suspected or actual) and provides updates on the incidents as well as cybersecurity risk mitigation activities
Cybersecurity Risk Role of Management [Text Block]	Our IT head, in turn reports to the Senior Vice-President and General Counsel who is responsible for and knowledgeable of legal and contractual cybersecurity risk for the organization. The program is comprised of policies, standards, architecture, and processes, which are reviewed and updated on a periodic basis. The program leverages a multilayered approach of utilizing different practices, technologies, vendors or techniques without an overreliance on a single vendor.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Senior Vice-President and General Counsel
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our IT head has more than 25 years of IT experience in the biopharmaceutical industry where she has been responsible for technology leadership and digital transformation across core operations.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	IT team provides regular updates to the Audit Committee on our IT security strategy, secure score assessments, penetration testing results, and status of risk mitigation activities, where applicable.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation The balance sheets and statements of operations and comprehensive loss, stockholders’ equity, and cash flows, are consolidated for the years ended December 31, 2024, 2023 and 2022. These consolidated financial statements reflect the operations of the Company and its wholly-owned subsidiary. All intercompany balances and transactions have been eliminated in consolidation.
Segment Information	Segment Information The Company is managed as a single operating and reportable segment that operates in the business of development, manufacturing and commercialization of novel therapeutics for human health care. Our chief operating decision maker (“CODM”), the Chief Executive Officer, evaluates performance based on consolidated net loss. Other than general and administrative expenses as presented on the consolidated statement of operations, research and development expense disaggregated by program and by nature are considered to be the Company’s significant segment expenses. These results are used, in part, by our CODM in evaluating the performance of the Company by comparing budget to actual results, and to allocate resources. All revenue is derived in and long-lived assets are located in the United States. The CODM does not receive asset information other than what is presented on the consolidated balance sheets. The following table is a summary of the Company’s research and development expenses disaggregated by program. The amounts disclosed reflect direct research and development costs and an allocation of indirect research and development costs to each program. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended ​ ​ Year Ended ​ December 31, 2024 December 31, 2023 December 31, 2022 ​ ​ (In thousands) Barzolvolimab/Anti-KIT Program $ 123,750 $ 79,913 ​ $ 51,220 CDX-622 ​ 17,341 ​ 16,299 ​ 5,613 CDX-585 ​ 2,813 ​ 6,357 ​ 9,793 Other Programs (a) ​ 19,646 ​ 15,442 ​ 15,632 Total R&D Expense ​ $ 163,550 ​ $ 118,011 ​ $ 82,258 ​ (a) Other program expenses primarily include research and development expenses related to early-stage programs, revenue-generating programs and discontinued programs. The following table is a summary of the Company’s research and development expenses disaggregated by nature. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended ​ Year Ended ​ December 31, 2024 December 31, 2023 December 31, 2022 ​ ​ (In thousands) Personnel $ 51,906 $ 40,121 $ 32,674 Laboratory Supplies ​ 5,611 ​ 5,358 ​ 6,310 Facility ​ 5,094 ​ 4,970 ​ 4,764 Product Development (b) ​ 90,604 ​ 59,319 ​ 32,156 Other Expenses (c) ​ 10,335 ​ 8,243 ​ 6,354 Total R&D Expense ​ $ 163,550 ​ $ 118,011 ​ $ 82,258 ​ (b) Product development expenses include clinical investigator site fees, external trial monitoring costs, data accumulation costs, contracted research and outside clinical drug product manufacturing. (c) Other expenses primarily include research and development consulting, insurance, licensing and software expenses.
Use of Estimates	Use of Estimates The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP) requires management to make estimates and use assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with a maturity date of 90 days or less at the date of purchase to be cash equivalents. Cash equivalents consist principally of money market funds and debt securities.
Marketable Securities	Marketable Securities The Company invests its excess cash balances in marketable securities, including municipal bond securities, U.S. government agency securities, and highly rated corporate bonds. The Company classifies all of its marketable securities as current assets on the balance sheets because they are available-for-sale and available to fund current operations. Marketable securities are stated at fair value with unrealized gains and losses included as a component of accumulated other comprehensive income (loss), which is a separate component of stockholders’ equity. Each reporting period, the Company evaluates its investment portfolio to determine if any security is impaired and if an allowance for credit losses should be recorded. As part of this evaluation, the Company considers whether it has the ability and intent to hold the investment until recovery of its amortized cost basis and whether the decline in fair value is due to any credit related factors. If an impairment is the result of a credit loss, the Company recognizes an allowance for credit losses. Realized gains and losses are determined on the specific identification method and are included in investment and other income, net.
Concentration of Credit Risk and of Significant Customers and Suppliers	Concentration of Credit Risk and of Significant Customers and Suppliers Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of cash, cash equivalents, marketable securities and accounts receivable. The Company invests its cash, cash equivalents and marketable securities in debt instruments and interest-bearing accounts at major financial institutions in excess of insured limits. The Company mitigates credit risk by limiting the investment type and maturity to securities that preserve capital, maintain liquidity and have a high credit quality. The Company has not historically experienced credit losses from its accounts receivable and therefore has not established an allowance for doubtful accounts. Revenue from Rockefeller University represented 100%, 95% and 75% of total Company revenue for the years ended December 31, 2024, 2023 and 2022, respectively. The Company relies on contract development & manufacturing organizations (CDMOs) to manufacture drug substance and drug product as well as for future commercial supplies. The Company also relies on CDMOs for supply of raw materials as well as filling, packaging, storing and shipping our drug products.
Fair Value Measurements	Fair Value Measurements The Company has certain assets and liabilities that are measured at fair value in the financial statements. The Company seeks to maximize the use of observable inputs (market data obtained from sources independent from the Company) and to minimize the use of unobservable inputs (the Company’s assumptions about how market participants would price assets and liabilities) when measuring the fair value of its assets and liabilities. These assets and liabilities are classified into one of three levels of the following fair value hierarchy as defined by U.S. GAAP: Level 1: Observable inputs such as quoted prices in active markets for identical assets or liabilities. An active market for an asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. Level 2: Observable inputs other than Level 1 prices, such as quoted prices in active markets for similar assets or liabilities and quoted prices for identical assets or liabilities in markets that are not active. Level 3: Unobservable inputs based on the Company’s assessment of the assumptions that market participants would use in pricing the asset or liability.
Property and Equipment	Property and Equipment Property and equipment are stated at cost and depreciated over the estimated useful lives of the related assets using the straight-line method. Laboratory seven The treatment of costs to construct property and equipment depends on the nature of the costs and the stage of construction. Costs incurred in the project planning, design, construction and installation phases are capitalized as part of the cost of the asset. The Company stops capitalizing these costs when the asset is substantially complete and ready for its intended use. For manufacturing property and equipment, the Company also capitalizes the cost of validating these assets for the underlying manufacturing process. The Company completes the capitalization of validation costs when the asset is substantially complete and ready for its intended use. Costs capitalized include incremental labor and fringe benefits, and direct consultancy services.
Leases	Leases The Company has operating leases of office, manufacturing and laboratory space, which have remaining lease terms of one The Company determines if an arrangement contains a lease at inception. Operating lease right-of-use assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Certain adjustments to the right-of-use asset may be required for items such as prepaid or accrued lease payments, initial direct costs paid or incentives received. The Company’s leases do not contain an implicit rate, and therefore the Company uses an estimated incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. Options to extend or terminate the lease are reflected in the calculation when it is reasonably certain that the option will be exercised. The Company has elected to account for lease and non-lease components as a single lease component, however non-lease components that are variable, such as common area maintenance and utilities, are generally paid separately from rent based on actual costs incurred and therefore are not included in the right-of-use asset and operating lease liability and are reflected as an expense in the period incurred. Leases with an initial term of 12 months or less are not recorded on the balance sheet.
Contingent Consideration	Contingent Consideration The Company records contingent consideration resulting from a business combination at its fair value on the acquisition date. The Company determines the fair value of the contingent consideration based primarily on the (i) timing and probability of success of clinical events or regulatory approvals; (ii) timing and probability of success of meeting clinical and commercial milestones; and (iii) discount rates. The Company’s contingent consideration liabilities arose in connection with its acquisition of Kolltan. On a quarterly basis, the Company revalues these obligations and records increases or decreases in their fair value as an adjustment to operating earnings. Changes to contingent consideration obligations can result from adjustments to discount rates, accretion of the discount rates due to the passage of time, changes in the Company’s estimates of the likelihood or timing of achieving development or commercial milestones, changes in the probability of certain clinical events or changes in the assumed probability associated with regulatory approval. The assumptions related to determining the 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.
Intangible Assets	Intangible Assets IPR&D assets acquired in a business combination initially are recorded at fair value and accounted for as indefinite-lived intangible assets. The valuation model used to measure the fair value of the Company’s IPR&D assets was primarily a discounted cash flow approach. The assumptions used in determining the fair value of the Company’s IPR&D assets include (i) probability of success; (ii) probability of partnership; (iii) partnership milestones; and (iv) discount rate. These assets are capitalized on the Company’s balance sheets until either the project underlying them is completed or the assets become impaired. If a project is completed, the carrying value of the related intangible asset is amortized over the remaining estimated life of the asset beginning in the period in which the project is completed. If a project becomes impaired or is abandoned, the carrying value of the related intangible asset is written down to its fair value and an impairment charge is taken in the period in which the impairment occurs. Each IPR&D asset is assessed for impairment at least annually or when impairment indicators are present. The Company has the option to assess qualitative factors to determine if it is more likely than not that the IPR&D asset is impaired and whether it is necessary to perform a quantitative impairment test.
Impairment of Intangible and Long-Lived Assets	Impairment of Intangible and Long-Lived Assets The Company evaluates the recoverability of its long-lived assets, including property and equipment, right-of-use assets, and intangible assets when circumstances indicate that an event of impairment may have occurred. Determination of recoverability is based on an estimate of undiscounted future cash flows resulting from the use of the asset and its eventual disposition. In the event that such cash flows are not expected to be sufficient to recover the carrying amount of the assets, the assets are written-down to their estimated fair values.
Revenue Recognition	Revenue Recognition Revenues are recognized when performance obligations under agreements or contracts are satisfied, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. The Company determines revenue recognition through the following steps: ● Identification of the contract, or contracts, with a customer; ● Identification of the performance obligations in the contract; ● Determination of the transaction price; ● Allocation of the transaction price to the performance obligations in the contract; and ● Recognition of revenue when, or as, the Company satisfies a performance obligation. Revenue for the Company is derived from product development agreements with collaborative partners for the research and development of therapeutic drug candidates. The terms of the agreements may include nonrefundable signing and licensing fees, funding for research, development and manufacturing, milestone payments and royalties on any product sales derived from collaborations. The Company assesses the multiple obligations typically within product development contracts to determine the distinct performance obligations and how to allocate the arrangement consideration to each distinct performance obligation. Under product development agreements, revenue is generally recognized using a cost-to-cost measure of progress. Revenue is recognized based on the costs incurred to date as a percentage of the total estimated costs to fulfill the contract. Incurred cost represents work performed, which corresponds with, and thereby best depicts, the transfer of control to the customer. Due to the nature of the work performed in these arrangements, the estimation of cost at completion is complex, subject to many variables, such as expected clinical trial costs, and requires significant judgements. Circumstances can arise that change original estimates of costs or progress toward completion. Any revisions to estimates are reflected in revenue on a cumulative catch-up basis in the period in which the change in circumstances became known. Revenue for the Company is also derived from manufacturing and research and development arrangements. The Company operates a cGMP manufacturing facility in Fall River, Massachusetts, to produce drug substance for its current and planned early-stage clinical trials. In order to utilize excess capacity, the Company has, from time to time, entered into contract manufacturing and research and development arrangements in which services are provided on a time-and-material basis or at a negotiated fixed price. Revenue from time-and-material contracts is generally recognized on an output basis as labor hours and/or direct expenses are incurred. Under fixed-price contracts, revenue is generally recognized on an output basis as progress is made toward completion of the performance obligations using surveys of performance completed to date.
Contract Assets and Liabilities	Contract Assets and Liabilities The Company classifies the right to consideration in exchange for products or services transferred to a client as either a receivable or a contract asset. A receivable is a right to consideration that is unconditional as compared to a contract asset which is a right to consideration that is conditional upon factors other than the passage of time. The Company’s contract liabilities result from arrangements where the Company has received payment in advance of performance under the contract. These amounts are included as deferred revenue within current portion of long-term liabilities on the consolidated balance sheets.
Research and Development Expenses	Research and Development Expenses Research and development costs, including internal and contract research costs, are expensed as incurred. Research and development expenses consist mainly of clinical trial costs, manufacturing of clinical material, toxicology and other preclinical studies, personnel costs, depreciation, license fees and funding of outside contracted research. Clinical trial expenses include expenses associated with clinical research organization, or CRO, services. Contract manufacturing expenses include expenses associated with contract development & manufacturing organization, or CDMO, services. The invoicing from CROs and CDMOs for services rendered can lag several months. The Company accrues the cost of services rendered in connection with CRO and CDMO activities based on our estimate of costs incurred. The Company maintains regular communication with our CROs and CDMOs to assess the reasonableness of its estimates. Differences between actual expenses and estimated expenses recorded have not been material and are adjusted for in the period in which they become known.
Patent Costs	Patent Costs Patent costs are expensed to general and administrative expense as incurred. Certain patent costs are reimbursed by the Company’s product development and licensing partners. Any reimbursed patent costs are recorded as product development and licensing agreement revenues in the Company’s consolidated financial statements.
Stock-Based Compensation	Stock-Based Compensation The Company records stock-based compensation expense for all stock-based awards made to employees, consultants and non-employee directors based on the estimated fair values of the stock-based awards expected to vest at the grant date and adjusts, if necessary, to reflect actual forfeitures. Compensation expense for all stock-based awards is recognized using the straight-line method over the term of vesting or performance.
Foreign Currency Translation	Foreign Currency Translation Net unrealized gains and losses resulting from foreign currency translation are included in accumulated other comprehensive income. At December 31, 2024 and 2023, accumulated other comprehensive income includes a net unrealized gain related to foreign currency translation of $2.6 million.
Income Taxes	Income Taxes The Company uses the asset and liability method to account for income taxes, including the recognition of deferred tax assets and deferred tax liabilities for the anticipated future tax consequences attributable to differences between financial statement amounts and their respective tax basis. Quarterly, the Company reviews its deferred tax assets for recovery. A valuation allowance is established when the Company believes that it is more likely than not that its deferred tax assets will not be realized. Changes in valuation allowances from period to period are included in the Company’s tax provision in the period of change. The Company records uncertain tax positions in the financial statements only if it is more likely than not that the uncertain tax position will be sustained upon examination by the taxing authorities. The Company records interest and penalties related to uncertain tax positions in income tax expense.
Comprehensive Loss	Comprehensive Loss Comprehensive loss is comprised of net loss and certain changes in stockholders’ equity that are excluded from net loss. The Company includes foreign currency translation adjustments and unrealized gains and losses on marketable securities in other comprehensive loss. The statements of operations and comprehensive loss reflect total comprehensive loss for the years ended December 31, 2024, 2023 and 2022.
Net Loss Per Share	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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2024 2023 2022 Stock ​ 7,540,109 ​ 6,378,924 ​ 5,085,662 ​
Newly-Adopted Accounting Pronouncements	Newly-Adopted Accounting Pronouncements In November 2023, the FASB issued ASU 2023-07 Segment Reporting - Improvements to Reportable Segment Disclosures
Recent Accounting Pronouncements	Recent Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that are adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the adoption of recently issued standards that are not yet effective will not have a material impact on the Company’s consolidated financial statements or disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, In March 2024, the SEC adopted final rules requiring public entities to provide certain climate-related information in their registration statements and annual reports. The rules require disclosure of, among other things: material climate-related risks; activities to mitigate or adapt to such risks; governance and management of such risks; and material greenhouse gas (GHG) emissions from operations owned or controlled (Scope 1) and/or indirect emissions from purchased energy consumed in operations (Scope 2). Additionally, the rules require disclosure in the notes to the financial statements of the effects of severe weather events and other natural conditions, subject to certain materiality thresholds. In April 2024, the SEC voluntarily stayed the new rules as a result of pending legal challenges. Absent the result of pending legal challenges, and the removal of the stay, the rules were to become effective on a phased-in timeline, with the first requirements to be adopted for the Company’s fiscal year beginning in 2025. The Company is assessing the effect of the new rules on its consolidated financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Schedule of research and development costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended ​ ​ Year Ended ​ December 31, 2024 December 31, 2023 December 31, 2022 ​ ​ (In thousands) Barzolvolimab/Anti-KIT Program $ 123,750 $ 79,913 ​ $ 51,220 CDX-622 ​ 17,341 ​ 16,299 ​ 5,613 CDX-585 ​ 2,813 ​ 6,357 ​ 9,793 Other Programs (a) ​ 19,646 ​ 15,442 ​ 15,632 Total R&D Expense ​ $ 163,550 ​ $ 118,011 ​ $ 82,258 ​ (a) Other program expenses primarily include research and development expenses related to early-stage programs, revenue-generating programs and discontinued programs. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ Year Ended ​ Year Ended ​ December 31, 2024 December 31, 2023 December 31, 2022 ​ ​ (In thousands) Personnel $ 51,906 $ 40,121 $ 32,674 Laboratory Supplies ​ 5,611 ​ 5,358 ​ 6,310 Facility ​ 5,094 ​ 4,970 ​ 4,764 Product Development (b) ​ 90,604 ​ 59,319 ​ 32,156 Other Expenses (c) ​ 10,335 ​ 8,243 ​ 6,354 Total R&D Expense ​ $ 163,550 ​ $ 118,011 ​ $ 82,258 ​ (b) Product development expenses include clinical investigator site fees, external trial monitoring costs, data accumulation costs, contracted research and outside clinical drug product manufacturing. (c) Other expenses primarily include research and development consulting, insurance, licensing and software expenses.
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	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2024 2023 2022 Stock ​ 7,540,109 ​ 6,378,924 ​ 5,085,662

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2024
Accumulated Other Comprehensive Income
Schedule of changes in accumulated other comprehensive income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unrealized ​ ​ ​ ​ ​ ​ Gain (Loss) on ​ ​ ​ ​ ​ ​ ​ ​ Marketable ​ Foreign ​ ​ ​ ​ ​ Securities ​ Currency Items ​ Total ​ ​ (In thousands) Balance at December 31, 2023 ​ $ 712 ​ $ 2,596 ​ $ 3,308 Other comprehensive gain ​ ​ 6 ​ ​ — ​ ​ 6 Balance at December 31, 2024 ​ $ 718 ​ $ 2,596 ​ $ 3,314 ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2024
Fair Value Measurements
Schedule of financial assets and liabilities subject to fair value measurements	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ December 31, 2024 ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 9,927 — ​ $ 9,927 ​ — Marketable securities ​ ​ 696,925 — ​ ​ 696,925 ​ — ​ ​ $ 706,852 ​ — ​ $ 706,852 ​ ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ ​ ​ ​ ​ ​ December 31, 2023 ​ Level 1 ​ Level 2 ​ Level 3 ​ ​ (In thousands) Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market funds and cash equivalents ​ $ 19,803 — ​ $ 19,803 ​ — Marketable securities ​ ​ 388,784 — ​ ​ 388,784 ​ — ​ ​ $ 408,587 ​ — ​ $ 408,587 ​ ​ — ​

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
	Dec. 31, 2024
Marketable Securities
Schedule of marketable debt securities, classified as available-for-sale	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Fair ​ ​ Cost ​ Gains ​ Losses ​ Value ​ ​ (In thousands) December 31, 2024 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 185,388 ​ $ 467 ​ $ — ​ $ 185,855 Maturing after one year through three years ​ ​ 102,331 ​ ​ 316 ​ ​ (144) ​ ​ 102,503 Total U.S. government and municipal obligations ​ $ 287,719 ​ $ 783 ​ $ (144) ​ $ 288,358 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 336,350 ​ $ 350 ​ $ (54) ​ $ 336,646 Maturing after one year through three years ​ ​ 72,139 ​ ​ 36 ​ ​ (254) ​ ​ 71,921 Total corporate debt securities ​ $ 408,489 ​ $ 386 ​ $ (308) ​ $ 408,567 Total marketable securities ​ $ 696,208 ​ $ 1,169 ​ $ (452) ​ $ 696,925 December 31, 2023 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Marketable securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. government and municipal obligations ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 132,459 ​ $ 143 ​ $ (53) ​ $ 132,549 Maturing after one year through three years ​ ​ 26,009 ​ ​ 77 ​ ​ — ​ ​ 26,086 Total U.S. government and municipal obligations ​ $ 158,468 ​ $ 220 ​ $ (53) ​ $ 158,635 Corporate debt securities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Maturing in one year or less ​ $ 183,625 ​ $ 300 ​ $ (10) ​ $ 183,915 Maturing after one year through three years ​ ​ 45,977 ​ ​ 257 ​ ​ — ​ ​ 46,234 Total corporate debt securities ​ $ 229,602 ​ $ 557 ​ $ (10) ​ $ 230,149 Total marketable securities ​ $ 388,070 ​ $ 777 ​ $ (63) ​ $ 388,784 ​

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2024
Property and Equipment, Net
Schedule of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Laboratory equipment ​ $ 10,411 ​ $ 9,848 Manufacturing equipment ​ 3,010 ​ 2,419 Office furniture and equipment ​ 3,965 ​ 3,738 Leasehold improvements ​ 10,285 ​ 9,653 Construction in progress ​ 139 ​ 787 Total property and equipment ​ 27,810 ​ 26,445 Less: accumulated depreciation and amortization ​ (23,464) ​ (22,385) Property and equipment, net ​ $ 4,346 ​ $ 4,060 ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2024
Leases
Schedule of future minimum lease payments under non-cancellable leases	Future minimum lease payments under non-cancellable leases as of December 31, 2024 were as follows: ​ ​ ​ ​ 2025 $ 1,761 2026 ​ ​ 1,779 2027 ​ 742 Total lease payments ​ 4,282 Less imputed interest ​ (469) Present value of operating lease liabilities ​ $ 3,813 ​

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2024
Accrued Expenses
Schedule of accrued expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Accrued payroll and employee benefits ​ $ 11,568 ​ $ 9,348 Accrued research and development contract costs ​ ​ 20,544 ​ ​ 10,864 Accrued professional fees ​ ​ 1,392 ​ ​ 1,439 Other accrued expenses ​ ​ 338 ​ ​ 378 ​ ​ $ 33,842 ​ $ 22,029 ​

Other Long-Term Liabilities (Ta

Other Long-Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2024
Other Long-Term Liabilities
Schedule of other long-term liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Net deferred tax liabilities related to IPR&D (Note 16) ​ $ 1,613 ​ $ 1,613 Deferred income from sale of tax benefits ​ ​ 2,790 ​ ​ 3,720 Deferred revenue (Note 14) ​ ​ 12 ​ ​ 3,058 Total ​ ​ 4,415 ​ ​ 8,391 Less current portion ​ ​ (942) ​ ​ (3,988) Long-term portion ​ $ 3,473 ​ $ 4,403

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2024
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, 2023 ​ 6,378,924 ​ $ 29.69 ​ 7.5 Granted ​ 1,959,320 ​ $ 36.22 ​ — Exercised ​ (679,985) ​ $ 12.98 ​ — Canceled ​ (118,150) ​ $ 120.67 ​ — Options outstanding at December 31, 2024 ​ 7,540,109 ​ $ 31.47 ​ 7.5 Options vested and expected to vest at December 31, 2024 ​ 7,416,025 ​ $ 31.41 ​ 7.4 Options exercisable at December 31, 2024 ​ 3,980,565 ​ $ 29.17 ​ 6.3 Shares available for grant under the Celldex Therapeutics, Inc. 2021 Omnibus Equity Incentive Plan (as amended, effective as of June 13, 2024) at December 31, 2024 ​ 2,372,333 ​ ​ — ​ —
Schedule of stock-based compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 ​ ​ (In thousands) Research and development ​ $ 17,442 ​ $ 11,948 ​ $ 8,082 General and administrative ​ ​ 16,800 ​ ​ 11,942 ​ ​ 7,529 Total stock-based compensation expense ​ $ 34,242 ​ $ 23,890 ​ $ 15,611
Schedule of assumptions used for the fair value of employee stock options granted	​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 Expected stock price volatility ​ 82 - 93% ​ 92% ​ 90 - 97% Expected option term ​ 6.0 Years ​ 6.0 Years ​ 6.0 Years Risk-free interest rate ​ 3.5 - 4.5% ​ 3.5 - 4.7% ​ 1.7 - 4.2% Expected dividend yield ​ None ​ None ​ None

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2024
Income Taxes
Schedule of components of income tax benefit (provision)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2024 2023 2022 ​ ​ (In thousands) Income tax benefit (provision): ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 39,821 ​ $ 36,067 ​ $ 17,484 State ​ ​ 15,375 ​ ​ 13,691 ​ ​ 9,606 Expiration of NOLs and R&D credit ​ ​ (82,825) ​ ​ (15,141) ​ ​ (16,862) ​ ​ ​ (27,629) ​ ​ 34,617 ​ ​ 10,228 Deferred tax valuation allowance ​ ​ 27,629 ​ ​ (34,617) ​ ​ (10,228) ​ ​ $ — ​ $ — ​ $ — ​
Schedule of reconciliation between the amount of reported income tax and the amount computed using the U.S. Statutory rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 ​ ​ (In thousands) Pre-tax loss ​ $ (157,863) ​ $ (141,429) ​ $ (112,325) Loss at statutory rates ​ ​ (33,151) ​ ​ (29,700) ​ ​ (23,588) Research and development credits ​ ​ (7,332) ​ ​ (5,237) ​ ​ (3,876) State taxes ​ ​ (15,375) ​ ​ (13,691) ​ ​ (9,606) Other ​ ​ 662 ​ ​ (1,130) ​ ​ 11,421 Change in fair value remeasurement of contingent consideration ​ ​ — ​ ​ — ​ ​ (1,441) Expiration of Federal and State NOLs and R&D credits ​ ​ 82,825 ​ ​ 15,141 ​ ​ 16,862 Change in valuation allowance ​ ​ (27,629) ​ ​ 34,617 ​ ​ 10,228 Income tax (benefit) provision ​ $ — ​ $ — ​ $ — ​
Schedule of principal components of the deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 ​ ​ (In thousands) Gross deferred tax assets ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 176,816 ​ $ 197,618 Tax credit carryforwards ​ ​ 24,718 ​ ​ 56,830 Deferred research and development expenses ​ ​ 101,047 ​ ​ 82,077 Stock-based compensation ​ ​ 20,940 ​ ​ 14,671 Fixed assets ​ ​ 1,033 ​ ​ 1,019 Accrued expenses and other ​ ​ 429 ​ ​ 398 ​ ​ ​ 324,983 ​ ​ 352,613 Gross deferred tax liabilities ​ ​ ​ ​ ​ ​ IPR&D intangibles ​ ​ (6,840) ​ ​ (6,840) Total deferred tax assets and liabilities ​ ​ 318,143 ​ ​ 345,773 Valuation allowance ​ ​ (319,756) ​ ​ (347,386) Net deferred tax liability ​ $ (1,613) ​ $ (1,613)

Nature of Business and Overvi_2

Nature of Business and Overview (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Nature of Business and Overview
Cash, cash equivalents and marketable securities	$ 725,300
Net loss	(157,863)	$ (141,429)	$ (112,325)
Net cash used in operations	$ (157,778)	$ (107,291)	$ (103,732)

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Summary of Significant Accounting Policies
Research and development	$ 163,550	$ 118,011	$ 82,258
Single reportable segment
Summary of Significant Accounting Policies
Research and development	163,550	118,011	82,258
Single reportable segment | Barzolvolimab/Anti-KIT Program
Summary of Significant Accounting Policies
Research and development	123,750	79,913	51,220
Single reportable segment | CDX-622
Summary of Significant Accounting Policies
Research and development	17,341	16,299	5,613
Single reportable segment | CDX-585
Summary of Significant Accounting Policies
Research and development	2,813	6,357	9,793
Single reportable segment | Other Programs (a)
Summary of Significant Accounting Policies
Research and development	$ 19,646	$ 15,442	$ 15,632

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Segment Information - Other Program (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Summary of Significant Accounting Policies
Research and Development Expense, Total	$ 163,550	$ 118,011	$ 82,258
Single reportable segment
Summary of Significant Accounting Policies
Personnel	51,906	40,121	32,674
Laboratory Supplies	5,611	5,358	6,310
Facility	5,094	4,970	4,764
Product Development	90,604	59,319	32,156
Other Expenses	10,335	8,243	6,354
Research and Development Expense, Total	$ 163,550	$ 118,011	$ 82,258

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Concentration of Credit Risk and Significant Customers and Suppliers (Details)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue | Rockefeller University | Customer concentration
Concentration risk
Concentration risk (as a percent)	100%	95%	75%

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Property and Equipment (Details)	Dec. 31, 2024
Laboratory equipment
Property and Equipment
Useful lives (in years)	5 years
Office furniture and equipment
Property and Equipment
Useful lives (in years)	5 years
Computer equipment
Property and Equipment
Useful lives (in years)	3 years
Manufacturing equipment | Minimum
Property and Equipment
Useful lives (in years)	7 years
Manufacturing equipment | Maximum
Property and Equipment
Useful lives (in years)	10 years

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Leases (Details)	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Lessee, Operating Lease, Existence of Option to Terminate [true false]	true
Minimum
Summary of Significant Accounting Policies
Remaining lease term (in years)	1 year
Maximum
Summary of Significant Accounting Policies
Remaining lease term (in years)	3 years

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Foreign Currency Translation (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Summary of Significant Accounting Policies
Unrealized gain related to foreign currency translation included in AOCI	$ 2.6	$ 2.6

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Net Loss Per Share (Details) - shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Employee Stock Option
Net Loss Per Share
Potentially dilutive common shares not been included in net loss per common share calculations because the effect would have been anti-dilutive	7,540,109	6,378,924	5,085,662

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive Income
Balance, beginning	$ 429,171	$ 326,204	$ 419,476
Balance, ending	747,005	429,171	326,204
Amounts reclassified from AOCI	0	0	0
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income
Balance, beginning	3,308	1,260	1,894
Other comprehensive loss	6
Balance, ending	3,314	3,308	$ 1,260
Unrealized Gain (Loss) on Marketable Securities
Accumulated Other Comprehensive Income
Balance, beginning	712
Other comprehensive loss	6
Balance, ending	718	712
Foreign Currency Items
Accumulated Other Comprehensive Income
Balance, beginning	2,596
Balance, ending	$ 2,596	$ 2,596

Fair Value Measurements (Detail

Fair Value Measurements (Details) - Fair Value Measurements - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Assets:
Money market funds and cash equivalents	$ 9,927	$ 19,803
Marketable securities	696,925	388,784
Total financial assets at fair value measurements	706,852	408,587
Level 2
Assets:
Money market funds and cash equivalents	9,927	19,803
Marketable securities	696,925	388,784
Total financial assets at fair value measurements	$ 706,852	$ 408,587

Fair Value Measurements - Addit

Fair Value Measurements - Additional information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Fair value measurements
Gain or loss on fair value remeasurement of contingent consideration			$ 6,862
Level 3
Fair value measurements
Contingent consideration liabilities	$ 0	$ 0
Fair value
Fair value measurements
Assets level 1 to level 2 transfers	0	0
Assets level 2 to level 1 transfers	0	0
Liabilities level 1 to level 2 transfers	0	0
Liabilities level 2 to level 1 transfers	0	0
Asset transfer out of level 3	0	0
Asset transfer into level 3	0	0
Liabilities transfers out of level 3	0	0
Liabilities transfers into level 3	$ 0	$ 0

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Amortized Cost
Amortized Cost	$ 696,208	$ 388,070
Gross Unrealized Gains
Gross Unrealized Gains	1,169	777
Gross Unrealized Losses
Gross Unrealized Losses	(452)	(63)
Fair Value
Fair Value	696,925	388,784
U.S. government and municipal obligations
Amortized Cost
Maturing in one year or less	185,388	132,459
Maturing after one year through three years	102,331	26,009
Amortized Cost	287,719	158,468
Gross Unrealized Gains
Maturing in one year or less	467	143
Maturing after one year through three years	316	77
Gross Unrealized Gains	783	220
Gross Unrealized Losses
Maturing in one year or less		(53)
Maturing after one year through three years	(144)
Gross Unrealized Losses	(144)	(53)
Fair Value
Maturing in one year or less	185,855	132,549
Maturing after one year through three years	102,503	26,086
Fair Value	288,358	158,635
Corporate debt securities
Amortized Cost
Maturing in one year or less	336,350	183,625
Maturing after one year through three years	72,139	45,977
Amortized Cost	408,489	229,602
Gross Unrealized Gains
Maturing in one year or less	350	300
Maturing after one year through three years	36	257
Gross Unrealized Gains	386	557
Gross Unrealized Losses
Maturing in one year or less	(54)	(10)
Maturing after one year through three years	(254)
Gross Unrealized Losses	(308)	(10)
Fair Value
Maturing in one year or less	336,646	183,915
Maturing after one year through three years	71,921	46,234
Fair Value	$ 408,567	$ 230,149

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($) item	Dec. 31, 2023 USD ($)
Marketable Securities
Unrealized loss	$ 142.5	$ 80.4
Number of investment grade marketable securities, considered to be other than temporarily impaired | item	0
Accrued interest	$ 6.1	$ 1.9

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property and Equipment
Total property and equipment	$ 27,810	$ 26,445
Less: accumulated depreciation and amortization	(23,464)	(22,385)
Property and equipment, net	4,346	4,060
Depreciation and amortization expense	3,177	3,008	$ 2,896
Laboratory equipment
Property and Equipment
Total property and equipment	10,411	9,848
Manufacturing equipment
Property and Equipment
Total property and equipment	3,010	2,419
Office furniture and equipment
Property and Equipment
Total property and equipment	3,965	3,738
Leasehold improvements
Property and Equipment
Total property and equipment	10,285	9,653
Construction in progress
Property and Equipment
Total property and equipment	139	787
Property and equipment
Property and Equipment
Depreciation and amortization expense	$ 1,600	$ 1,500	$ 1,400

Leases (Details)

Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Leases
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Increase in right of use assets for new leases and lease extensions	$ 2.9	$ 0.1	$ 2.5
Increase in lease liabilities for new lease and lease extensions	2.9	0.1	2.5
Operating lease expense	2	1.9	1.9
Variable lease expense	0.8	0.8	0.8
Operating lease payments	$ 2	$ 2	$ 1.9
Weighted-average remaining lease term	2 years	2 years
Weighted-average discount rate	10%	10%
Minimum
Leases
Remaining lease term (in years)	1 year
Maximum
Leases
Remaining lease term (in years)	3 years

Leases - Future minimum lease p

Leases - Future minimum lease payments under non-cancellable leases (Details) $ in Thousands	Dec. 31, 2024 USD ($)
Operating lease liabilities, payments due
2025	$ 1,761
2026	1,779
2027	742
Total lease payments	4,282
Less imputed interest	(469)
Present value of operating lease liabilities	$ 3,813

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Intangible Assets
Indefinite-lived intangible assets	$ 27.2	$ 27.2

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Other Assets
Advance payment	$ 9.6	$ 0

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Accrued Expenses
Accrued payroll and employee benefits	$ 11,568	$ 9,348
Accrued research and development contract costs	20,544	10,864
Accrued professional fees	1,392	1,439
Other accrued expenses	338	378
Accrued expenses	$ 33,842	$ 22,029

Other Long-Term Liabilities (De

Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Other Long-Term Liabilities
Net deferred tax liabilities related to IPR&D (Note 16)	$ 1,613	$ 1,613
Deferred income from sale of tax benefits	2,790	3,720
Deferred revenue (Note 14)	12	3,058
Total	4,415	8,391
Less current portion	(942)	(3,988)
Long-term portion	$ 3,473	$ 4,403

Other Long-Term Liabilities - A

Other Long-Term Liabilities - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Long-Term Liabilities
Other income		$ 37,215	$ 13,113	$ 2,909
New Jersey Economic Development Authority
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
Other income		$ 900	$ 900

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Mar. 31, 2024	Nov. 30, 2023	Dec. 31, 2024	Dec. 31, 2023
Stockholders' Equity
Net proceeds from sale of common stock			$ 432,298	$ 216,222
Preferred stock, shares authorized (in shares)			3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)			0	0
Series C-1 Preferred Stock
Stockholders' Equity
Preferred stock, shares authorized (in shares)			350,000
Preferred stock, shares outstanding (in shares)			0	0
ATM Agreement
Stockholders' Equity
Common stock to be sold pursuant			$ 300,000
Underwritten Public Offering
Stockholders' Equity
Common stock issued (in shares)	9,798,000	8,538,750
Net proceeds from sale of common stock	$ 432,300	$ 216,200

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee Stock Purchase Plan (Details) - shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
2004 ESPP Plan
Stock-Based Compensation
Available for issuance (in shares)	150,316
Common stock reserved for issuance (in shares)	276,666
Purchase price of fair value of common stock (in percent)	85%
Issued (in shares)	13,187	12,729	12,243
2008 Plan
Stock-Based Compensation
Available for issuance (in shares)	0

Stock-Based Compensation - Em_2

Stock-Based Compensation - Employee Stock Option (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock-Based Compensation
Weighted average period compensation cost is expected to be recognized (in years)	2 years 7 months 6 days
Stock Options
Stock-Based Compensation
Shares outstanding (in shares)	1,513,850
Vesting period (in years)	4 years
Expiration period (in years)	10 years
Intrinsic value of stock options exercised	$ 17.2	$ 2.7	$ 12.8
Weighted average grant-date fair value (in dollars per share)	$ 26.21	$ 28.15	$ 17.6
Fair value of stock options vested	$ 32.4	$ 20.4	$ 15.6
Intrinsic value of stock options outstanding	24.4
Intrinsic value of stock options vested and expected to vest	24.4
Intrinsic value of stock options exercisable	23
Compensation cost not yet recognized	$ 77.1
Stock Options | Principal Owner
Stock-Based Compensation
Expiration period (in years)	5 years
Exercise price as a percentage of fair market value	110%

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) - Employee Stock Option - $ / shares	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Shares
Options outstanding at beginning of the period	6,378,924
Granted	1,959,320
Exercised	(679,985)
Canceled	(118,150)
Options outstanding at the end of the period	7,540,109	6,378,924
Options vested and expected to vest at the end of the period	7,416,025
Options exercisable at the end of the period	3,980,565
Shares available for grant under the Celldex Therapeutics, Inc. 2021 Omnibus Equity Incentive Plan (as amended, effective as of June 13, 2024) at December 31, 2024	2,372,333
Weighted Average Exercise Price Per Share
Options outstanding at beginning of the period	$ 29.69
Granted	36.22
Exercised	12.98
Canceled	120.67
Options outstanding at the end of the period	31.47	$ 29.69
Options vested and expected to Vest at the end of the period	31.41
Options exercisable at the end of the period	$ 29.17
Weighted Average Remaining Contractual Term (In Years)
Options outstanding at the beginning of the period	7 years 6 months	7 years 6 months
Options vested and expected to vest at the end of the period	7 years 4 months 24 days
Options exercisable at the end of the period	6 years 3 months 18 days

Stock-Based Compensation - Expe

Stock-Based Compensation - Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock-Based Compensation
Total stock-based compensation expense	$ 34,242	$ 23,890	$ 15,611
Research and development
Stock-Based Compensation
Total stock-based compensation expense	17,442	11,948	8,082
General and administrative
Stock-Based Compensation
Total stock-based compensation expense	$ 16,800	$ 11,942	$ 7,529

Stock-Based Compensation - Valu

Stock-Based Compensation - Valuation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Black-Scholes option with following assumptions:
Dividend payouts	$ 0
Expected dividend payments	$ 0
Employee Stock Option
Black-Scholes option with following assumptions:
Expected stock price volatility (as a percent)		92%
Expected stock price volatility, minimum (as a percent)	82%		90%
Expected stock price volatility, maximum (as a percent)	93%		97%
Expected option term	6 years	6 years	6 years
Risk-free interest rate, minimum (as a percent)	3.50%	3.50%	1.70%
Risk-free interest rate, maximum (as a percent)	4.50%	4.70%	4.20%
Expected dividend yield (as a percent)	0%	0%	0%

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenue
Revenues	$ 7,020	$ 6,883	$ 2,357
Contract assets	0	0
Contract liabilities	12	3,058
Revenue, contract liabilities	3,100
Contracts and grants
Revenue
Revenues	7,007	6,605	2,301
Rockefeller University | Contracts and grants
Revenue
Revenues	$ 7,000	$ 6,600	$ 1,800

Collaboration Agreements (Detai

Collaboration Agreements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Collaborative Agreements
License fee expense	$ 0.2	$ 0.3	$ 0.1
Yale | License agreement with Yale
Collaborative Agreements
Potential milestone payment	$ 3

Income Taxes - Benefit (Provisi

Income Taxes - Benefit (Provision) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income tax benefit (provision):
Federal	$ 39,821	$ 36,067	$ 17,484
State	15,375	13,691	9,606
Expiration of NOLs and R&D credit	(82,825)	(15,141)	(16,862)
Income tax benefit (provision) before valuation allowance	(27,629)	34,617	10,228
Deferred tax valuation allowance	$ 27,629	$ (34,617)	$ (10,228)

Income Taxes - Reconciliation (

Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reconciliation between the amount of reported income tax and the amount computed using U.S. Statutory rate
Pre-tax loss	$ (157,863)	$ (141,429)	$ (112,325)
Loss at statutory rates	(33,151)	(29,700)	(23,588)
Research and development credits	(7,332)	(5,237)	(3,876)
State taxes	(15,375)	(13,691)	(9,606)
Other	662	(1,130)	11,421
Change in fair value remeasurement of contingent consideration			(1,441)
Expiration of Federal and State NOLs and R&D credits	82,825	15,141	16,862
Change in valuation allowance	$ (27,629)	$ 34,617	$ 10,228

Income Taxes - Summary of defer

Income Taxes - Summary of deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Gross deferred tax assets
Net operating loss carryforwards	$ 176,816	$ 197,618
Tax credit carryforwards	24,718	56,830
Deferred research and development expenses	101,047	82,077
Stock-based compensation	20,940	14,671
Fixed assets	1,033	1,019
Accrued expenses and other	429	398
Deferred tax assets, gross	324,983	352,613
Gross deferred tax liabilities
IPR&D intangibles	(6,840)	(6,840)
Total deferred tax assets and liabilities	318,143	345,773
Valuation allowance	(319,756)	(347,386)
Net deferred tax liability	$ (1,613)	$ (1,613)

Income Taxes - Carryforwards (D

Income Taxes - Carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Income Taxes
Net deferred tax liability	$ 1,613	$ 1,613
Federal
Income Taxes
Net operating loss carryforwards	566,000
Federal NOL carryforwards	758,700
Tax credit carryforwards	48,700
Federal | R&D credit
Income Taxes
Net operating loss carryforwards	19,800
State
Income Taxes
Net operating loss carryforwards	888,800
State | R&D credit
Income Taxes
Net operating loss carryforwards	$ 6,300

Retirement Savings Plan (Detail

Retirement Savings Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Retirement Savings Plan
Maximum contribution by participants (as a percent)	60%
Employer matching contributions (as a percent)	50%
Maximum percentage of employees' gross pay subject to employer matching contributions	4%
Benefit expense for the 401(k) Plan	$ 0.5	$ 0.5	$ 0.4

Kolltan Acquisition (Details)

Kolltan Acquisition (Details) - Kolltan - USD ($) $ in Millions	Jul. 15, 2022	Nov. 29, 2016
Kolltan Acquisition
Shares issued as part of consideration (in shares)		1,217,200
Execution of the settlement agreement	$ 15
Milestone payments made in cash upon Successful Completion of a Phase 2 Clinical Trial	12.5
Milestone payment payable upon regulatory approval of a Surviving Company Product	52.5
Specified development, regulatory approvals or sales-based milestones
Kolltan Acquisition
Potential milestone payments		$ 172.5
Milestone payment payable upon regulatory approval of a Surviving Company Product	$ 172.5