Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Activity Relating to Restricted Stock Units

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

	Shares			Weighted Average Grant Date Fair Value
Outstanding as of December 31, 2022		1,415,481		$	48.73
Granted		2,639,729		$	30.38
Vested		(326,530	)	$	51.06
Forfeited		(640,286	)	$	41.63
Outstanding as of December 31, 2023		3,088,394		$	34.27

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

The following table 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, 2022		7,788,350		$	77.95		6.36	$	7,275
Granted		964,253		$	44.58
Exercised		(65,940	)	$	16.58
Forfeited		(568,622	)	$	56.00
Outstanding as of December 31, 2023		8,118,041		$	76.02		5.66	$	475
Vested and expected to vest as of December 31, 2023		7,389,812		$	76.55		5.47	$	455
Exercisable as of December 31, 2023		6,116,989		$	81.94		4.84	$	403

Summary of Stock-Based Compensation Expense Recognized

The following table summarizes stock-based compensation expense recognized during the years ended December 31, 2023, 2022 and 2021:

	Year Ended December 31,
	2023		2022		2021
	(in thousands)
Research and development	$	24,813	$	25,888	$	49,746
Selling, general and administrative		47,716		35,714		54,883
Restructuring		838		—		—
	$	73,367	$	61,602	$	104,629

Summary of Stock-Based Compensation Expense by Award Type

The following table summarizes stock-based compensation expense by award type recognized during the years ended December 31, 2023, 2022 and 2021:

	Year Ended December 31,
	2023		2022		2021
	(in thousands)
Stock options	$	47,695	$	54,971	$	78,516
Restricted stock units		24,424		5,587		25,375
Employee stock purchase plan		1,248		1,044		738
	$	73,367	$	61,602	$	104,629

Summary of Weighted Average Assumptions Used to Compute Fair Value of Option Granted

The fair value of each stock option granted under the Company’s equity plans has been calculated on the date of grant using the following weighted average assumptions:

	Year Ended December 31,
	2023			2022			2021
Expected dividend yield		0	%		0	%		0	%
Expected volatility		72	%		73	%		76	%
Risk-free interest rate		3.85	%		2.49	%		0.63	%
Expected term	6.01 years			6.03 years			5.92 years