Condensed Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net loss	$ (42,393)	$ (27,747)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	9,447	6,202
Depreciation expense	6	6
Accretion of discounts on debt securities	(599)	0
Amortization of operating right-of-use assets	83	47
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,396	422
Deposits and other long-term assets	(18)	4
Accounts payable	4,379	(1,043)
Accrued expenses and other current liabilities	1,810	595
Operating lease liabilities	(96)	(49)
Net cash used in operating activities	(25,985)	(21,563)
Cash flows from investing activities
Cash paid for purchase of short-term investments	(160,014)	0
Proceeds from maturity of short-term investments	148,847	0
Cash paid for purchase of property and equipment	(26)	(15)
Cash used in investing activities	(11,193)	(15)
Cash flows from financing activities
Proceeds from issuance of common stock upon stock option exercises	1,184	0
Net cash provided by financing activities	1,184	0
Net increase in cash and cash equivalents	(35,994)	(21,578)
Cash and cash equivalents, beginning of period	85,262	284,309
Cash and cash equivalents, end of period	49,268	262,731
Supplemental disclosures of noncash activities
Purchases of property and equipment included in accounts payable and in accrued expenses and other current liabilities	$ 32	$ 0