Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2024

Summary of Stock Options

Stock option activity during the six months ended June 30, 2024 is as follows:

	Shares subject to options			Weighted- average exercise price		Weighted- average remaining contractual term (years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of January 1, 2024		10,376,838		$	6.38	6.9		$	—
Granted		3,183,515			1.03
Replacement options from Exchange		1,906,153			0.96
Exercised		—			—				—
Forfeited or Expired		(1,544,211	)		6.73
Cancelled options from Exchange		(3,880,332	)		10.43
Outstanding as of June 30, 2024		10,041,963			2.04		8.20		—
Options vested and expected to vest as of June 30, 2024		10,041,963			2.04		8.20		—
Options vested and exercisable as of June 30, 2024		3,436,608			3.70		5.97		—

Summary of Stock Based Compensation Expense Was Allocated

Stock-based compensation expense was allocated as follows for the three and six months ended June 30, 2024 and 2023 (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2024		2023		2024		2023
Research and development	$	1,194	$	1,572	$	2,634	$	3,743
General and administrative		862		1,625		2,070		3,117
Total	$	2,056	$	3,197	$	4,704	$	6,860

Restricted Stock [Member]

Summary of Stock Options

Restricted stock activity during the six months ended June 30, 2024 is as follows:

	Number of Awards				Weighted- Average Grant Date Fair Value		Aggregate Fair Value (in thousands)
Issued and unvested as of January 1, 2024		134,120		$		0.84	$	113
Restricted stock awards granted		22,950				1.13		26
Restricted stock awards vested		(2,490	)			0.84		(2	)
Issued and unvested as of June 30, 2024		154,580		$		0.88	$	137