Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2026

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, 2025	9,134,278	$	26.49	7.1
Granted	78,100	$	27.98	—
Exercised	(7,442)	$	14.65	—
Canceled	(133,333)	$	33.17	—
Options outstanding at March 31, 2026	9,071,603	$	26.41	6.9
Options vested and expected to vest at March 31, 2026	8,974,496	$	26.41	6.9
Options exercisable at March 31, 2026	5,488,328	$	26.49	5.8
Shares available for grant under the Celldex Therapeutics, Inc. 2021 Omnibus Equity Incentive Plan (as amended, effective as of June 5, 2025) at March 31, 2026	2,680,069

Schedule of stock-based compensation expense

	Three Months Ended March 31,
	2026		2025
	(In thousands)
Research and development	$	4,647	$	4,585
General and administrative		3,876		4,731
Total stock-based compensation expense	$	8,523	$	9,316

Schedule of assumptions used for the fair value of employee stock options granted

	Three Months Ended March 31,
	2026	2025
Expected stock price volatility	74 – 76%	76 – 81%
Expected option term	6.0 Years	6.0 Years
Risk-free interest rate	3.8 – 4.2%	4.2 – 4.7%
Expected dividend yield	None	None