Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Option Valuation Assumptions

The assumptions that the Company used in the Black-Scholes option-pricing model to determine the grant-date fair value of stock options granted for the years ended December 31, 2022 and 2021 were as follows:

	YEAR ENDED DECEMBER 31,
	2022			2021
Weighted-average risk-free interest rate	2.24		%	0.88		%
Expected term (in years)	6.06			6.05
Expected volatility	83.03		%	83.00		%
Expected dividend yield	0.00		%	0.00		%
Fair value of underlying common stock	$	31.18		$	42.29

Schedule of Option Activity

A summary of option activity during the years ended December 31, 2022 and 2021 is as follows (in thousands except share and per share data):

	NUMBER OF OPTIONS	WEIGHTED- AVERAGE EXERCISE PRICE		WEIGHTED-AVERAGE REMAINING CONTRACTUAL TERM (IN YEARS)	AGGREGATE INTRINSIC VALUE
Outstanding as of January 1, 2022	2,810,684	$	24.62	8.11	$	100,009
Granted	1,086,458	43.66
Exercised	(158,235)	5.17			$	5,637
Cancelled or forfeited	(195,428)	42.44
Expired	(10,310)	(59.46)
Outstanding as of December 31, 2022	3,533,169	$	30.26	7.77	$	72,434
Options vested as of December 31, 2022	1,749,888	$	19.59	6.93	$	53,895
Options unvested as of December 31, 2022	1,783,281	$	40.72

Schedule of Stock-based Compensation Expense

Total stock-based compensation expense recorded as research and development and general and administrative expenses, respectively, for employees, directors and non-employees during the years ended December 31, 2022 and 2021 is as follows (in thousands):

	YEAR ENDED DECEMBER 31,
	2022		2021
Research and development	$	8,205	$	4,258
General and administrative	10,477		7,464
Total stock-based compensation expense	$	18,682	$	11,722