Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Share-based Payment Arrangement [Abstract]

Summary of Weighted-Average Assumptions Used Principally in Determining Fair Value of Options Granted

The weighted-average assumptions used principally in determining the fair value of options granted were as follows:

	Year Ended December 31,
	2021			2020
Fair value of common stock	$	23.63		$	4.29
Expected term (in years)		6.0			6.0
Expected volatility		78.4	%		77.3	%
Risk-free interest rate		0.9	%		0.4	%
Dividend yield		—			—

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity for the year ended December 31, 2021:

	Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2020		5,084,679		$	3.79		9.42	$	32,086
Granted		730,884		$	19.46
Vested and exercised		(442,947	)	$	2.02
Forfeited		(285,698	)	$	4.10
Expired		(126	)	$	18.00
Outstanding at December 31, 2021		5,086,792		$	6.17		8.00	$	38,000
Exercisable at December 31, 2021		1,669,852		$	4.15		7.49	$	14,384

Summary of Stock-Based Compensation Expense

Stock-based compensation expense was allocated as follows:

	Year Ended December 31,
(in thousands)	2021		2020
Research and development	$	2,281	$	665
General and administrative		2,034		677
Total stock-based compensation expense	$	4,315	$	1,342