Equity Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Activity

The following table presents stock option activity under the Plans for the period:

	Number of Shares			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Balances as of December 31, 2023		9,208,970		$	10.31		7.53	$	2,930
Stock options granted		4,710,324		$	5.70
Stock options exercised		(248,907	)	$	3.69
Stock options forfeited		(912,703	)	$	10.96
Balances as of September 30, 2024		12,757,684		$	8.69		7.79	$	8,435
Exercisable as of September 30, 2024		6,429,000		$	11.22		6.55	$	4,278

Summary of RSU Activity under 2020 Plan

A summary of RSU activity under the Company’s equity incentive plan and related information is as follows:

	Number of Shares			Weighted-Average Grant Date Fair Value Per Share
Unvested as of December 31, 2023		495,579		$	5.69
Granted		602,600			5.13
Vested		(187,835	)		5.59
Cancelled		(127,635	)		5.29
Unvested as of September 30, 2024		782,709		$	5.35

Summary of Stock-Based Compensation Expense

The total stock-based compensation expense recognized was as follows (in thousands):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	2,325	$	2,243	$	6,918	$	6,801
General and administrative		2,284		2,306		7,293		7,015
Total stock-based compensation expense	$	4,609	$	4,549	$	14,211	$	13,816

Summary of Fair Value of Each Award Issued Estimated on the Date of Grant Using the Black-Scholes Option Pricing Model

The fair value of each stock option issued was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:

	Three Months Ended September 30,		Nine Months Ended September 30,
	2024	2023	2024	2023
Expected term (in years)	6.02 - 6.08	6.08	6.02 - 6.08	5.50 - 6.08
Expected volatility	96.80% - 97.60%	81.80% - 81.90%	95.90% - 97.80%	81.20% - 82.40%
Risk-free interest rate	3.48% - 4.15%	4.20% - 4.42%	3.48% - 4.65%	3.47% - 4.42%
Dividend yield	—	—	—	—