Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2022

Share-based Payment Arrangement [Abstract]

Summary of stock option activity

The following table summarizes stock option activity during the nine months ended September 30, 2022:

	Shares			Weighted average exercise price
Outstanding at January 1, 2022		2,301,574		$	78.90
Options granted		809,745			82.11
Options cancelled		(85,156	)		101.61
Outstanding at September 30, 2022		3,026,163		$	79.11
Exercisable at September 30, 2022		1,746,699		$	70.94

Schedule of stock-based compensation expense

Stock-based compensation expense during the nine months ended September 30, 2022 and 2021 was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Stock-based compensation expense by type of award:
Stock options	$	8,122	$	6,241	$	23,543	$	20,517
Total stock-based compensation expense	$	8,122	$	6,241	$	23,543	$	20,517
Effect of stock-based compensation expense by line item:
Research and development	$	3,596	$	2,622	$	10,084	$	8,120
General and administrative		4,526		3,619		13,459		12,397
Total stock-based compensation expense included in net loss	$	8,122	$	6,241	$	23,543	$	20,517