Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Schedule of Stock Based Compensation Expense Recognized

Stock-based compensation expense is recognized in the condensed consolidated statements of operations as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
	(in thousands)
Research and development	$	5,722	$	7,437	$	18,387	$	20,557
General and administrative		3,281		2,643		9,215		7,189
Total stock-based compensation expense	$	9,003	$	10,080	$	27,602	$	27,746

Schedule of Unrecognized Stock-Based Compensation Costs Related to Unvested Awards and Weighted-Average Period Over Which Costs are Expected to be Recognized

Unrecognized stock-based compensation costs related to unvested awards and the weighted-average period over which the costs are expected to be recognized as of September 30, 2023 are as follows:

	Stock Options		RSUs
Unrecognized stock-based compensation expense (in thousands)	$	62,145	$	5,851
Weighted-average period costs expected to be recognized (in years)		2.3		2.7

Summary of Stock Option Activity

A summary of the Company’s stock option activity is as follows:

	Stock Options (in thousands)			Weighted-Average Exercise Price per Share		Weighted-Average Remaining Contractual Life (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2022		23,686		$	7.79		8.3	$	10,628
Granted		8,161			3.96
Exercised		(693	)		1.78
Forfeited/Cancelled		(1,769	)		8.98
Outstanding as of September 30, 2023		29,385		$	6.79		8.0	$	10,236
Exercisable as of September 30, 2023		12,722		$	7.52		6.9	$	7,795

Schedule of Assumptions Used in Black-Scholes Option-Pricing Model for Estimating Fair Value of Stock Options Granted

The fair value of stock options granted to employees, directors, and consultants was estimated on the date of grant using the Black-Scholes option pricing model using the following assumptions:

	Nine Months Ended September 30,
Assumptions	2023	2022
Risk free interest rate	3.36% – 4.63%	1.56% – 3.94%
Expected volatility	70.0% – 72.5%	70.0%
Expected term (years)	5.50 – 6.50	5.50 – 6.25
Expected dividend	0%	0%

Summary of Additional Information Related to Stock Option Activity

The following table summarizes additional information related to stock option activity:

	Nine Months Ended September 30,
	2023		2022
Weighted average grant date fair value per share for options granted	$	2.62	$	3.96
Aggregate intrinsic value of stock options exercised (in thousands)	$	2,426	$	5,854

Summary of RSU Activity

A summary of the Company’s RSU activity is as follows:

	RSUs (in thousands)			RSUs Weighted-Average Grant Date Fair Value per Share
Unvested shares as of December 31, 2022		885		$	6.66
Granted		1,364			3.83
Vested		(342	)		7.28
Forfeited		(229	)		4.99
Unvested shares as of September 30, 2023		1,678		$	4.44