Stock Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2025

Share-Based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense by classification included within the consolidated statements of operations and comprehensive loss, was as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2025		2024		2025		2024
Research and development	$	1,005	$	799	$	4,090	$	2,287
General and administrative	1,585		896		4,287		2,430
Total stock-based compensation expense	$	2,590	$	1,695	$	8,377	$	4,717

Schedule of Weighted Average Assumptions Used

The estimated grant date fair values of stock option awards granted under the 2016 Plan and the 2018 Inducement Incentive Award Plan were calculated using the Black-Scholes option pricing model based on the following weighted-average assumptions:


	Three Months Ended September 30,						Nine Months Ended September 30,
	2025			2024			2025			2024
Risk-free interest rate	3.95		%	4.05		%	4.42		%	4.04		%
Dividend yield	—			—			—			—
Expected term (in years)	6.25			6.23			6.20			6.20
Expected volatility	93.79		%	94.98		%	97.19		%	95.07		%
Weighted-average fair value of common stock	$	12.48		$	17.97		$	16.87		$	19.79

Schedule of Options Activity

The following table summarizes the stock option activity under the 2016 Plan, the 2018 Inducement Incentive Award Plan, and the Old Cartesian Plan for options for common stock:


	Number of common stock options	Weighted-average exercise price ($)		Weighted-average remaining contractual term (in years)	Aggregate intrinsic value (in thousands)









Outstanding at December 31, 2024	1,706,035	$	11.99	7.59	$	12,025
Granted	1,055,709	$	16.87
Exercised	(82,944)	$	3.29
Forfeited	(245,144)	$	17.74
Outstanding at September 30, 2025	2,433,656	$	13.83	7.25	$	5,087

Vested at September 30, 2025	895,577	$	7.76	4.83	$	4,698
Vested and expected to vest at September 30, 2025	2,189,301	$	13.40	7.18	$	5,085

Schedule of Restricted Stock Units Activity

The following table summarizes the Company’s restricted stock units under the 2016 Plan and the Old Cartesian Plan:


	Number of shares	Weighted-average grant date fair value ($)
Unvested at December 31, 2024	444,238	$	19.86
Granted	256,790	16.93
Vested	(153,293)	19.86

Forfeited	(24,481)	17.07
Unvested at September 30, 2025	523,254	$	18.55

Cartesian Therapeutics, Inc. 10-Q