Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (123,321)	$ (97,263)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	1,823	1,535
Stock-based compensation expense	22,598	10,437
Noncash lease expense	1,858	1,669
(Accretion) amortization on short-term investments	(1,806)	1,262
Changes in operating assets and liabilities:
Accounts receivable	15	7,281
Prepaid expenses and other current assets	(294)	(2,266)
Other non-current assets	201	70
Accounts payable	(1,351)	891
Accrued liabilities	7,904	2,695
Operating lease liabilities	(2,258)	(1,754)
Net cash used in operating activities	(94,631)	(75,443)
Cash flows from investing activities:
Purchase of short-term investments	(325,716)	(219,887)
Maturity of short-term investments	177,272	295,539
Purchase of property and equipment	(1,760)	(1,953)
Net cash (used in) provided by investing activities	(150,204)	73,699
Cash flows from financing activities:
Proceeds from sale of common stock in a public offering	216,201	0
Proceeds term loan, net of issuance costs	9,850	0
Proceeds from issuances of common stock under benefit plans	1,360	2,984
Payment of offering costs	(557)	(457)
Net cash provided by financing activities	226,854	2,527
Net (decrease) increase in cash and cash equivalents	(17,981)	783
Cash and cash equivalents at beginning of period	51,665	50,882
Cash and cash equivalents at end of period	33,684	51,665
Supplemental disclosures of cash flow information:
Cash paid for interest	615	0
Supplemental disclosures of noncash investing and financing activities:
Purchase of property and equipment in accounts payable and accrued liabilities	0	57
Reclassification of restricted stock awards from liabilities to common stock upon vesting	2	9
Net unrealized loss on short-term investments	(1,757)	(169)
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 950	$ 0