Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Operating activities:
Net loss	$ (26,681)	$ (13,405)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation and amortization expense	81	26
Accretion of discount and amortization of premium on investments, net	(372)	98
Stock-based compensation	3,471	3,948
Loss on disposal of assets	0	1
Gain on change in fair value of warrant liability	0	(638)
Gain on change in fair value of earn-out liability	(6)	(12,124)
Other expense related to equity purchase agreement	29	1,161
Non-cash interest expense	237	263
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	402	714
Other non-current assets	144	144
Accounts payable	(392)	635
Accrued expenses	(898)	57
Operating lease right-of-use assets and liabilities, net	1	1
Net cash used in operating activities	(23,984)	(19,119)
Investing activities:
Purchases of fixed assets	(43)	(179)
Maturities of short-term investments	22,750	25,500
Purchases of short-term investments	(17,169)	(46,803)
Net cash provided by (used in) investing activities	5,538	(21,482)
Financing activities:
Payment of debt issuance costs	0	(37)
Proceeds from exercise of common stock options and warrants	56	3
Proceeds from issuance of common stock - Registered direct offerings, net of issuance costs	14,523	0
Proceeds from issuance of common stock including ESPP, net of issuance costs	545	2,836
Net cash provided by financing activities	15,124	2,802
Net increase (decrease) in cash and cash equivalents	(3,322)	(37,799)
Cash and cash equivalents at beginning of period	8,708	49,702
Cash and cash equivalents at end of period	5,386	11,903
Supplemental disclosure of cash flow information:
Interest paid	1,874	1,295
Supplemental disclosure of non-cash investing and financing activities:
Issuance of commitment shares	0	862
Accrued issuance costs	7	197
Purchases of fixed assets included in accounts payable and accrued expenses	$ 55	$ 4