Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

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 September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
	(In thousands)				(In thousands)
Research and development	$	4,058	$	1,935	$	10,631	$	5,515
General and administrative		3,972		2,169		10,989		5,528
Total stock-based compensation	$	8,030	$	4,104	$	21,620	$	11,043

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, 2019		994,838		$	6.95
Vested		(579,317	)		6.95
Unvested restricted common stock as of    September 30, 2020		415,521		$	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, 2019		8,442,824		$	12.79
Granted		2,536,087			21.42
Exercised		(583,591	)		9.77
Forfeited		(362,050	)		16.53
Outstanding as of September 30, 2020		10,033,270		$	15.01		8.7	$	6,402
Exercisable as of September 30, 2020		2,834,348		$	12.22		8.3	$	3,017
Vested and expected to vest as of September 30, 2020		10,033,270		$	15.01		8.7	$	6,402