Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Stock-Based Compensation [Abstract]

Weighted-Average Assumptions for Stock Options

The weighted average assumptions that the Company used in a Black-Scholes pricing model to determine the fair value of stock options granted to employees, non-employees and directors were as follows:

	Three Months Ended March 31,
	2024			2023
Risk-free interest rate		5.16	%		4.02	%
Expected term (in years)		5.88			5.88
Expected volatility		73.62	%		73.54	%
Expected dividend yield		0.00	%		0.00	%
Exercise price	$	29.46		$	20.17
Fair value of common stock	$	29.46		$	20.17

Stock Option Activity

The following table summarizes stock option activity for the three months ended March 31, 2024:

				Weighted		Weighted
				Average		Average		Aggregate
	Number of			Exercise		Contractual		Intrinsic
	Shares			Price		Term (Years)		Value
Outstanding as of December 31, 2023		14,863,996		$	15.07		5.16	$	250,602
Granted		1,174,939			29.46		9.88
Exercised		(73,745	)		16.05				956
Cancelled or forfeited		(41,384	)		18.18
Outstanding as of March 31, 2024		15,923,806		$	16.12		5.24	$	208,603
Options vested and exercisable as of March 31, 2024		12,351,611		$	14.14		4.14	$	190,665
Options unvested as of March 31, 2024		3,572,195		$	22.94		9.04	$	17,937

RSU Activity

The following table summarizes the Company’s RSU activity for the three months ended March 31, 2024:

				Weighted Average
	Number of			Grant Date
	Shares			Fair Value
Unvested as of December 31, 2023		1,490,357		$	18.53
Granted		566,366			29.24
Vested		(290,578	)		19.38
Forfeited		(25,400	)		17.04
Unvested as of March 31, 2024		1,740,745		$	21.89

PSU Activity

The following table summarizes the Company’s PSU activity for the three months ended March 31, 2024:

			Weighted Average
	Number of		Grant Date
	Shares		Fair Value
Unvested as of December 31, 2023		-	$	-
Granted		139,323		28.71
Vested		-		-
Forfeited		-		-
Unvested as of March 31, 2024		139,323	$	28.71

PSU vesting and expense recognition is based on achievement of specific performance goals within certain time periods. PSU awards that are not achieved within specific time periods are forfeited. No performance goals were probable of achievement and no time periods had expired on grant date and as of March 31, 2024.

Stock-Based Compensation Expense by Award Type

Stock-based compensation expense recognized by award type was as follows:

	Three Months Ended March 31,
	2024		2023
Stock options	$	6,938	$	6,985
Restricted stock units		3,314		1,930
Total stock-based compensation expense	$	10,252	$	8,915

Stock-Based Compensation Expense

Stock-based compensation expense by classification included within the Consolidated Statements of Operations and Comprehensive Loss was as follows:

	Three Months Ended March 31,
	2024		2023
Research and development	$	4,637	$	3,819
General and administrative		5,615		5,096
Total stock-based compensation expense	$	10,252	$	8,915