Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flow from operating activities:
Net loss	$ (16,520)	$ (10,910)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation expense	2,384	1,024
Depreciation and amortization expense	21	11
Accretion of discounts and amortization of premiums on investments, net	(671)	29
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	636	2,129
Other long-term assets	(89)	(25)
Accounts payable	2,121	1,587
Accrued and other liabilities	716	497
Operating lease assets and liabilities, net	(31)	(3)
Other liabilities	9
Net cash used in operating activities	(11,424)	(5,661)
Cash flow from investing activities:
Purchases of short-term investments	(15,609)	(32,890)
Maturities of short-term investments	31,000	12,519
Purchases of property and equipment	(16)	(28)
Net cash provided by (used in) investing activities	15,375	(20,399)
Cash flow from financing activities:
Proceeds from exercise of stock options	223
Net cash provided by financing activities	223
Net increase (decrease) in cash and cash equivalents	4,174	(26,060)
Cash and cash equivalents at the beginning of the year	22,397	54,197
Cash and cash equivalents at the end of the period	26,571	28,137
Supplemental disclosure of noncash investing and financing activities:
Deferred offering costs included in accounts payable	104
Purchases of property and equipment in accounts payable	$ 30	$ 85