Net Loss per Share - Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Numerator:
Net loss	$ (71,174)	$ (56,624)
Loss attributable to common stockholders - basic	(71,174)	(56,624)
Loss attributable to common stockholders - diluted	$ (71,174)	$ (56,624)
Denominator:
Weighted-average shares outstanding	125,862,975	92,164,419
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Loss per share applicable to common stockholders - basic	$ (0.57)	$ (0.61)
Loss per share applicable to common stockholders - diluted	$ (0.57)	$ (0.61)
Stock Options to Purchase Common Stock [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	16,826,144	14,820,313
Unvested Restricted Stock Units [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	4,215,834	1,582,641
Shares Issuable under ESPP [Member]
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:
Anti-dilutive potential common stock equivalents excluded from the calculation of net loss per share:	68,594	32,355