Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Recognized Stock-Based Compensation

The Company recognized stock-based compensation as follows:

	Three Months Ended March 31,
	2021		2020
	(In thousands)
Research and development	$	4,363	$	3,111
General and administrative		4,437		3,531
Total stock-based compensation	$	8,800	$	6,642

Summary of Restricted Common Stock

Activity for the restricted common stock is shown below:

	Number of Shares			Weighted Average Grant Date Fair Value per Share
Unvested restricted common stock as of    December 31, 2020		186,425		$	6.95
Vested		(85,544	)		6.95
Unvested restricted common stock as of March 31, 2021		100,881		$	6.95

Summary of Options to Purchase Common Stock

Activity for the options to purchase common stock shown below (in thousands, except share and per share amounts):

	Number of Options			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (In years)		Aggregate Intrinsic Value
Outstanding as of December 31, 2020		12,654,998		$	13.96
Granted		521,748			16.02
Exercised		(415,386	)		9.33
Forfeited		(126,927	)		16.03
Outstanding as of March 31, 2021		12,634,433		$	14.18		8.6	$	84,326
Exercisable as of March 31, 2021		3,893,199		$	13.27		8.0	$	28,021
Vested and expected to vest as of March 31, 2021		12,634,433		$	14.18		8.6	$	84,326