CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (10,048)	$ (9,788)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	696	689
Amortization of financing costs	472	198
Stock-based compensation	910	853
Decrease in the carrying amount of right-of-use assets	113	180
Decrease in:
Receivables	4	1,111
Prepaid expenses and other current assets	49	149
Other non-current assets	0	5
Decrease in:
Accounts payable	(110)	(763)
Accrued expenses	(1,334)	(214)
Lease liabilities	(133)	(190)
Net cash used in operating activities	(9,381)	(7,770)
Cash flows from investing activities:
Purchases of property and equipment	(61)	(29)
Proceeds from the disposal of property and equipment	38	0
Net cash used in investing activities	(23)	(29)
Cash flows from financing activities:
Proceeds from the issuance of common stock	92	0
Repayment of long-term debt	(6,250)	0
Net cash used in financing activities	(6,158)	0
Net decrease in cash, cash equivalents and restricted cash	(15,562)	(7,799)
Cash, cash equivalents and restricted cash, beginning of period	52,996	76,054
Cash, cash equivalents and restricted cash, end of period	37,434	68,255
Supplementary disclosure of cash flow information:
Cash paid for interest	439	484
Amounts included in accrued expenses and accounts payable related to property and equipment	$ 101	$ 29