CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (1,682)	$ (10,048)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2	696
Amortization of financing costs	0	472
Stock-based compensation	172	910
Decrease in the carrying amount of right-of-use assets	0	113
(Increase) decrease in:
Receivables	0	4
Prepaid expenses and other current assets	307	49
Increase (decrease) in:
Accounts payable	(19)	(110)
Accrued expenses	(697)	(1,334)
Lease liabilities	0	(133)
Net cash used in operating activities	(1,917)	(9,381)
Cash flows from investing activities:
Purchases of property and equipment	0	(61)
Proceeds from the disposal of property and equipment	0	38
Net cash used in investing activities	0	(23)
Cash flows from financing activities:
Proceeds from the issuance of common stock	0	92
Repayment of long-term debt	0	(6,250)
Net cash used in financing activities	0	(6,158)
Net decrease in cash, cash equivalents and restricted cash	(1,917)	(15,562)
Cash, cash equivalents and restricted cash, beginning of period	6,062	52,996
Cash and cash equivalents, end of period	4,145	37,434
Supplementary disclosure of cash flow information:
Cash paid for interest	0	439
Amounts included in accrued expenses and accounts payable related to property and equipment	$ 0	$ 101