Equity Incentive Plans (Tables)

3 Months Ended

Mar. 31, 2021

The following table summarizes stock option activity during the three months ended March 31, 2021:


	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, 2020	9,401,082	$	13.42	8.1	$	10,182
Options granted	2,215,526	$	9.82
Options exercised	(5,721)	$	2.61
Options forfeited/cancelled	(220,656)	$	16.06
Outstanding as of March 31, 2021	11,390,231	$	13.83	8.1	$	9,464
Options vested and exercisable as of March 31, 2021	4,431,654	$	12.76	7.3	$	6,558

The summary of the Company’s restricted stock activity is as follows:


	Number of Restricted Stock Units Outstanding	Weighted- Average Grant Date Fair Value
Nonvested at December 31, 2020	3,330,821	$	7.16
Granted	1,243,045	$	10.41
Vested	(517,521)	$	7.58
Forfeited	(45,156)	$	10.24
Nonvested at March 31, 2021	4,011,189	$	8.08

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


	Three months ended March 31,
	2021		2020
Research and development	$	5,442	$	4,586
General and administrative	3,266		3,658
Total stock-based compensation	$	8,708	$	8,244