CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net loss	$ (7,139)	$ (6,719)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization expense	48	26
Stock-based compensation	410	1,000
Amortization of premiums and accretion of discounts on investments, net	(56)	0
Other	31	38
Change in operating assets and liabilities:
Contracts and other receivables	(4)	(8)
Prepaid expenses and other assets	669	681
Accounts payable	406	340
Accrued liabilities	(290)	(26)
Accrued research and development expenses	(714)	(202)
Accrued compensation	(1,183)	(1,159)
Operating lease right-of-use assets and liabilities, net	(18)	(12)
Other liabilities	(274)	(340)
Net cash used in operating activities	(8,114)	(6,381)
Investing activities
Sales of short-term investments	15,000	0
Purchases of property and equipment	(1)	(102)
Net cash provided by (used in) investing activities	14,999	(102)
Financing activities
Proceeds from issuance of common stock, net	21	2
Principal payments on term loan	(826)	0
Net cash (used in) provided by financing activities	(805)	2
Net increase (decrease) in cash and cash equivalents	6,080	(6,481)
Cash and cash equivalents at beginning of period	24,290	60,445
Cash and cash equivalents at end of period	30,370	53,964
Reconciliation of cash, cash equivalents and restricted cash
Cash and cash equivalents	30,308	53,902
Restricted cash	62	62
Total cash, cash equivalents and restricted cash	30,370	53,964
Supplemental disclosure of cash flow information
Interest paid	(148)	(110)
Income taxes paid	0	(1)
Supplemental disclosure of non-cash investing and financing activities
Non-cash acquisition of property and equipment	$ 0	$ 33