Equity Incentive Plans (Tables)

6 Months Ended

Jun. 30, 2022

Share-based Payment Arrangement [Abstract]

The following table summarizes stock option activity during the six months ended June 30, 2022:


	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, 2021	9,434,660	$	12.24	7.4	$	15,822
Options granted	4,359,235	$	11.53
Options exercised	(47,530)	$	3.08
Options forfeited/cancelled	(562,456)	$	16.50
Outstanding as of June 30, 2022	13,183,909	$	11.86	7.7	$	6,900
Options vested and expected to vest as of June 30, 2022	13,183,909	$	11.86	7.7	$	6,900
Options exercisable as of June 30, 2022	5,924,728	$	12.01	6.4	$	6,506

Summary of Restricted Stock Activity

The summary of the Company’s restricted stock activity during the six months ended June 30, 2022 is as follows:


	Number of Restricted Stock Units Outstanding	Weighted- Average Grant Date Fair Value
Nonvested at December 31, 2021	2,561,219	$	8.67
Granted	572,901	11.94
Vested	(913,535)	8.30
Forfeited	(116,828)	10.54
Nonvested at June 30, 2022	2,103,757	$	9.62

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,
	2022		2021		2022		2021
Research and development	$	5,587	$	4,644	$	12,205	$	10,086
General and administrative	4,412		3,410		8,777		6,676
Total stock-based compensation expense	$	9,999	$	8,054	$	20,982	$	16,762