Equity Incentive Plans (Tables)

6 Months Ended

Jun. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Activity

The following table summarizes stock option activity during the six months ended June 30, 2023:

	Shares Subject to Options Outstanding			Weighted- Average
	Shares	Weighted- Average Exercise Price		Remaining Contractual Life (Years)	Aggregate Intrinsic Value
					(in thousands)
Outstanding as of December 31, 2022	17,487,165	$	9.24	8.1	$	47
Options granted	11,570,739	$	1.30
Options exercised	—	$	—
Options forfeited/cancelled	(9,318,846)	$	11.33
Outstanding as of June 30, 2023	19,739,058	$	3.59	7.4	$	1
Options vested and expected to vest as of June 30, 2023	19,739,058	$	3.59	7.4	$	1
Options exercisable as of June 30, 2023	8,065,502	$	5.83	5.6	$	—

Summary of Restricted Stock Activity

The summary of the Company’s restricted stock activity during the six months ended June 30, 2023 is as follows:

	Number of Restricted Stock Units Outstanding	Weighted- Average Grant Date Fair Value
Nonvested at December 31, 2022	1,350,035	$	10.83
Granted	—	—
Vested	(779,900)	10.67
Forfeited	(125,448)	11.37
Nonvested at June 30, 2023	444,687	$	10.95

Stock-Based Compensation Expense Reported in Condensed Consolidated Statements of Operations

Stock-based compensation expense has been reported in the Company’s condensed consolidated statements of operations and comprehensive loss as follows (in thousands):

	Three months ended June 30,				Six months ended June 30,
	2023		2022		2023		2022
Research and development	$	4,721	$	5,587	$	9,411	$	12,205
General and administrative	3,476		4,412		6,913		8,777
Total stock-based compensation expense	$	8,197	$	9,999	$	16,324	$	20,982