Stockholders’ Equity (Tables)

3 Months Ended

Mar. 31, 2021

Equity [Abstract]

Summary of Stock Option Activity

Stock option activity for employee and nonemployee awards and related information is as follows (in thousands, except per share data):

	Number of Options			Weighted- Average Exercise Price Per Share
Outstanding at December 31, 2020		3,788		$	9.06
Granted		1,766			23.33
Exercised		(31	)		0.78
Forfeited		—			—
Outstanding at March 31, 2021		5,523		$	13.67

Schedule of Assumptions Used in Black-Scholes Model Pricing Model to to Determine Fair Value of Stock Option and Shares Purchasable Under ESPP

The assumptions used in the Black-Scholes model to determine the fair value of stock option grants and shares purchasable under the ESPP were as follows:

	Three Months Ended March 31,
Stock Option Grants	2021	2020
Risk-free interest rate	0.5% - 1.1%	1.5%
Expected volatility	88%	88%
Expected term (in years)	5.8 - 6.1	6.0 - 6.1
Expected dividend yield	—%	—%

	Three Months Ended March 31,
ESPP	2021	2020
Risk-free interest rate	N/A	N/A
Expected volatility	N/A	N/A
Expected term (in years)	N/A	N/A
Expected dividend yield	N/A	N/A

Schedule of Allocated Stock-based Compensation Expense

The allocation of stock-based compensation expense was as follows (in thousands):

	Three Months Ended March 31,
	2021		2020
Research and development expense	$	2,010	$	81
General and administrative expense		1,691		368
Total stock-based compensation expense	$	3,701	$	449