Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity

Stock options

Stock option activity under the 2011 Plan and the 2020 Plan was as follows:

	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, 2020		3,909,873		$	10.78		8.40	$	56,128
Additional shares authorized
Stock options granted		2,871,400		$	25.54
Stock options exercised		(391,349	)	$	4.11
Stock options cancelled		(727,100	)	$	24.41
Balances as of December 31, 2021		5,662,824		$	16.98		8.26	$	10,186
Exercisable as of December 31, 2021		2,065,942		$	11.34		7.08	$	8,120

Summary of RSU Activity under Equity Incentive Plan

A summary of RSU activity under our 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, 2020		—	$	—
Granted		50,000		12.84
Unvested as of December 31, 2021		50,000	$	12.84

Summary of Stock-Based Compensation Expense

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

	Year Ended December 31,
	2021		2020
Research and development	$	8,610	$	2,274
General and administrative		7,652		2,614
Total stock-based compensation expense	$	16,262	$	4,888

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 award issued was estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions:

	Year Ended December 31,
	2021		2020
Expected term (in years)	4.33-6.08		5.00-6.08
Expected volatility	88%-91%		85%-93%
Risk-free interest rate	0.35%-1.31%		0.33%-1.45%
Dividend yield		—		—