Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Activity Relating to Restricted Stock Units

The table below summarizes activity relating to time-based restricted stock units and performance restricted stock units:

	Shares
Outstanding as of December 31, 2020		957,695
Granted		420,161
Vested		(218,017	)
Forfeited		(153,121	)
Outstanding as of September 30, 2021		1,006,718

Summary of Activity Relating to Time Based and Performance Based Stock Options

The table below summarizes activity related to time-based and performance-based stock options:

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2020		7,157,830		$	91.41		6.91	$	167,242
Granted		1,967,133		$	82.14
Exercised		(271,430	)	$	43.95
Forfeited		(1,215,809	)	$	121.85
Outstanding as of September 30, 2021		7,637,724		$	85.86		6.90	$	20,583
Exercisable as of September 30, 2021		4,344,625		$	84.79		5.58	$	19,215

Summary of Stock-Based Compensation Expense Recognized

Stock-based compensation expense recognized during the three and nine months ended September 30, 2021 and 2020 was as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
	(in thousands)
Research and development	$	17,864	$	9,927	$	40,598	$	32,270
Selling, general and administrative		16,478		10,181		43,383		41,192
Restructuring		—		—		—		1,788
	$	34,342	$	20,108	$	83,981	$	75,250

Summary of Stock-Based Compensation Expense by Award Type

Stock-based compensation expense recognized during the three and nine months ended September 30, 2021 and 2020 by award type was as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
	(in thousands)
Stock options	$	19,516	$	18,797	$	60,740	$	72,434
Restricted stock units		14,563		1,066		22,538		1,815
Employee stock purchase plan		263		245		703		1,001
	$	34,342	$	20,108	$	83,981	$	75,250