CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (27,297)	$ (28,571)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2,074	2,065
Property and equipment right-of-use asset impairment	1,011	0
Amortization of financing costs	1,339	634
Stock-based compensation	2,550	2,651
Decrease in the carrying amount of right-of-use assets	1,332	2,306
Gain on lease modification	(245)	(133)
Loss on disposal of equipment	12	0
(Increase) decrease in:
Receivables	4	(1,800)
Prepaid expenses and other current assets	(126)	817
Deposits	42	0
Other non-current assets	500	131
Increase (decrease) in:
Accounts payable	(92)	616
Accrued expenses	(2,258)	1,525
Lease liabilities	(1,575)	(2,371)
Other non-current liabilities	(28)	28
Net cash used in operating activities	(22,757)	(22,102)
Cash flows from investing activities:
Purchases of property and equipment	(197)	(100)
Proceeds from the disposal of property and equipment	40	0
Net cash used in investing activities	(157)	(100)
Cash flows from financing activities:
Proceeds from the issuance of common stock	92	0
Proceeds from the exercise of stock options	0	21
Repurchase of common stock	0	(45)
Repayment of long-term debt	(18,105)	(2,083)
Debt extinguishment costs	(125)	0
Net cash used in financing activities	(18,138)	(2,107)
Net decrease in cash, cash equivalents and restricted cash	(41,052)	(24,309)
Cash, cash equivalents and restricted cash, beginning of period	52,996	76,054
Cash and cash equivalents, end of period	11,944	51,745
Supplementary disclosure of cash flow information:
Cash paid for interest	2,063	1,603
Amounts included in accounts payable and accrued expenses related to property and equipment	$ 1	$ 348