Equity Incentive Plans and Stock-Based Compensation - Summary of Components and Classification of Stock-based Compensation Expense for Stock-based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,280	$ 786	$ 4,858	$ 1,211
Research and development expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	868	287	2,038	451
General and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,412	499	2,820	760
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	51	51	102	109
Stock options and ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,229	$ 735	$ 4,756	$ 1,102