Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities
Net loss	$ (7,156)	$ (9,291)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	122	636
Non-cash lease expense	5	8
Depreciation	2	19
Loss on sale of property and equipment		75
Change in fair value of warrant liabilities	(2,901)
Change in operating assets and liabilities:
Prepaid expenses and other assets	(161)	(627)
Accounts payable	1,273	114
Accrued and other liabilities	1,410	(839)
Net cash used in operating activities	(7,406)	(9,905)
Investing activities
Sale of property and equipment		8
Purchases of property and equipment	(41)
Net cash used in (provided by) investing activities	(41)	8
Financing activities
Payment of issuance costs	(80)	(134)
Net cash used in financing activities	(80)	(134)
Net decrease in cash	(7,527)	(10,031)
Cash at beginning of period	33,364	16,387
Cash at end of period	25,837	6,356
Supplemental non-cash investing and financing transactions:
Right-of-use assets obtained in exchange for new operating lease liabilities	223
Cash paid for amounts included in the measurement of lease liability	7
Modification of right-of-use asset and associated liability		62
Unpaid deferred issuance costs		$ 205
Reclassification of warrant liabilities upon exercise of warrants	$ 6,833