Condensed Consolidated Statements of Cash Flows $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($)	Mar. 31, 2024 USD ($)
Operating activities
Net loss	$ (14,211)	$ (10,707)
Reconciliation of net loss to net cash used in operating activities:
Stock-based compensation	987	902
Non-cash interest expense	119	161
Amortization of premium and interest on marketable securities	(253)	(278)
Depreciation expense	5	10
Loss on extinguishment of debt	0	942
Changes in operating assets and liabilities:
Prepaid expenses and other assets	873	1,226
Accounts payable	(67)	(72)
Accrued expenses	(164)	(1,759)
Net cash used in operating activities	(12,711)	(9,575)
Investing activities
Proceeds from sales and maturities of marketable securities	23,758	20,700
Net cash provided by investing activities	23,758	20,700
Financing activities
Proceeds from issuance of common stock upon at-the-market offering, net of issuance costs	0	29,656
Proceeds from issuance of common stock upon stock option exercises	0	320
Proceeds from issuance of common stock upon exercise of common warrants	0	450
Common stock repurchase	(17)	(26)
Payment of debt extinguishment costs	0	(150)
Net cash (used in) provided by financing activities	(17)	30,250
Increase in cash and cash equivalents	11,030	41,375
Cash and cash equivalents, beginning of period	49,464	49,255
Cash and cash equivalents, end of period	60,494	90,630
Supplemental disclosure of cash flow information
Cash paid for interest	806	887
Cash paid for taxes	19	28
Unsettled stock option exercise proceeds in prepaid expenses and other assets	$ 0	$ 162