Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (86,075)	$ (91,361)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	14,461	6,748
Depreciation and amortization expense	1,756	786
Accretion of discount and amortization of premium on investments, net	3,237	738
Non-cash lease expense	367	262
Change in fair value of preferred stock purchase right liability		40,163
Others	(30)	(14)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(4,435)	(3,645)
Accounts payable and accrued and other liabilities	2,792	2,817
Net cash used in operating activities	(67,927)	(43,506)
Cash flows from investing activities:
Purchases of available-for-sale securities	(227,282)	(222,570)
Proceeds from maturities of available-for-sale securities	264,841	20,000
Purchase of property and equipment	(5,025)	(7,511)
Net cash provided by (used in) investing activities	32,534	(210,081)
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock, net of issuance costs		64,321
Proceeds from initial public offering, net of issuance costs		265,096
Proceeds from stock option exercises	1,479	387
Proceeds from early exercise of stock options		13
Payments of deferred offering costs	(277)
Net cash provided by financing activities	1,202	329,817
Net (decrease) increase in cash and cash equivalents	(34,191)	76,230
Cash, cash equivalents and restricted cash at beginning of year	97,105	20,875
Cash, cash equivalents and restricted cash at end of year	62,914	97,105
Reconciliation of cash, cash equivalents and restricted cash to the balance sheets:
Cash and cash equivalents	60,816	96,692
Restricted cash	2,098	413
Total cash, cash equivalents and restricted cash	62,914	97,105
Supplemental disclosures of non-cash investing and financing activities:
Acquisitions of property and equipment	$ 238	$ 455