Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2022

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity

A summary of stock option activity during the six months ended June 30, 2022 is as follows:

	Number of Units Outstanding			Weighted Average Strike Price per Unit		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2021		8,590,411		$	5.48		8.8	$	6,196
Granted		4,347,646		$	1.08
Exercised		(65,862	)	$	1.50
Forfeited		(2,200,917	)	$	5.30
Expired		(422,657	)	$	4.51
Outstanding at June 30, 2022		10,248,621		$	3.72		9.0	$	—
Exercisable at June 30, 2022		2,804,018		$	5.33		8.1	$	—
Nonvested at June 30, 2022		7,444,603		$	3.11		9.4	$	—

Summary of Restricted Stock Unit Activity

A summary of RSU activity during the six months ended June 30, 2022 is as follows:

	Number of Units Outstanding			Weighted Average Grant Date Fair Value (per RSU)
Outstanding at December 31, 2021		407,720		$	5.72
Granted		324,300		$	1.24
Vested		—		$	—
Forfeited		(132,105	)	$	5.51
Outstanding at June 30, 2022		599,915		$	3.35

Components of Stock-based Compensation Expense

The following table summarizes the components of stock-based compensation expense recorded in the Company’s statement of operations and comprehensive loss (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Research and development	$	234	$	558	$	809	$	1,181
Selling, general and administrative		1,011		1,233		1,981		2,382
Total stock-based compensation	$	1,245	$	1,791	$	2,790	$	3,563