Stock-based compensation (Tables)

6 Months Ended

Jun. 30, 2022

Summary of Stock Options

Stock option activity during the six months ended June 30, 2022 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, 2022		5,692,514		$	12.07	8.63		$	16,763
Granted		3,742,124		$	3.01
Exercised		(5,591	)	$	1.92
Cancelled		(416,678	)	$	10.08
Outstanding as of June 30, 2022		9,012,369		$	8.41		8.61	$	200
Options vested and expected to vest as of June 30, 2022		9,006,650		$	8.41		8.61	$	200
Options vested and exercisable as of June 30, 2022		2,766,840		$	9.90		7.82	$	200

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, 2022 and 2021 (in thousands):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2022		2021		2022		2021
Research and development	$	2,199	$	1,974	$	4,200	$	3,683
General and administrative		1,795		1,474		3,580		2,521
Total	$	3,994	$	3,448	$	7,780	$	6,204

Restricted Stock [Member]

Summary of Stock Options

The following table summarizes the Company’s restricted common stock activity for the six months ended June 30, 2022:

	Number of Awards			Weighted- Average Grant Date Fair Value		Aggregate Fair Value (in thousands)
Issued and unvested as of January 1, 2022		89,054		$	1.30	$	117
Restricted stock awards granted		—
Restricted stock awards vested		(85,337	)	$	1.30	$	(111	)
Issued and unvested as of June 30, 2022		3,717		$	1.30	$	6