Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Cash flows from operating activities:
Net loss	$ (29,769)	$ (29,025)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	127	130
Stock-based compensation	1,984	2,275
License rights expense settled in stock	772	0
Change in fair value of warrant liability	1,044	(1,335)
Operating lease, net	119	92
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(272)	(857)
Accounts payable	403	731
Accrued expenses and other current liabilities	1,491	350
Net cash used in operating activities	(24,101)	(27,639)
Cash flows from investing activities:
Purchase of fixed assets	(124)	(67)
Net cash used in investing activities	(124)	(67)
Cash flows from financing activities:
Payment of tax liability for vested restricted stock units	(25)	(23)
Proceeds from sale of common stock, pre-funded and common warrants, net of issuance costs	4,166	0
Transaction costs allocated to warrant liabilities	510	0
Net cash provided by (used in) financing activities	4,651	(23)
Effect of exchange rate changes on cash and cash equivalents	(21)	(29)
Net change in cash and cash equivalents	(19,595)	(27,758)
Cash and cash equivalents, at beginning of year	43,145	70,903
Cash and cash equivalents, at end of year	23,550	43,145
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accrued liabilities	26	0
Offering costs included in accounts payable and accrued liabilities	115	0
Issuance of common stock to acquire license rights	$ 772	$ 0