Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		9 Months Ended
	Oct. 31, 2020	May 31, 2020	Sep. 30, 2020	Nov. 30, 2020	Nov. 03, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Shares authorized			57,932,090			33,645,447
Shares issued			48,958,829			33,645,447
Gross proceeds from issuance of preferred stock			$ 106,631
Convertible preferred stock converted into shares			48,958,829
Subsequent Event | IPO
Class Of Stock [Line Items]
Preferred stock purchase price				$ 24.00	$ 24.00
Series D Preferred
Class Of Stock [Line Items]
Shares authorized		15,313,382	15,313,382
Shares issued		15,313,382	15,313,382
Gross proceeds from issuance of preferred stock		$ 107,500
Preferred stock purchase price			$ 7.02
Convertible preferred stock converted into shares			15,313,382
Series D-1 Preferred
Class Of Stock [Line Items]
Shares authorized		8,973,261	8,973,261
Right to purchase price, per share		$ 11.98
Number of shares obligated to purchase upon milestone		2,991,087
Series D-1 Preferred | Subsequent Event
Class Of Stock [Line Items]
Shares issued	8,973,261
Gross proceeds from issuance of preferred stock	$ 107,500
Preferred stock purchase price	$ 11.98
Series D-1 Preferred | Subsequent Event | Maximum
Class Of Stock [Line Items]
Options to purchase shares	8,973,261
Convertible Preferred Stock
Class Of Stock [Line Items]
Shares authorized			57,932,090
Series A Preferred
Class Of Stock [Line Items]
Shares authorized			20,000,000
Shares issued			20,000,000
Preferred stock purchase price			$ 1.00
Convertible preferred stock converted into shares			20,000,000
Series B Preferred
Class Of Stock [Line Items]
Shares authorized			7,592,830
Shares issued			7,592,830
Preferred stock purchase price			$ 3.03
Convertible preferred stock converted into shares			7,592,830
Series C Preferred
Class Of Stock [Line Items]
Shares authorized			6,052,617
Shares issued			6,052,617
Preferred stock purchase price			$ 4.56
Convertible preferred stock converted into shares			6,052,617
Common Stock | Subsequent Event | IPO
Class Of Stock [Line Items]
Convertible preferred stock converted into shares				57,932,090