Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (7,113)	$ (4,779)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization expense	59	43
Net amortization of premiums and discounts on investments	0	(103)
Stock-based compensation expense	150	391
Loss on disposition of property and equipment	0	16
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	185	247
Other assets	1,301	24
Accounts payable	966	(1,262)
Operating lease liabilities	(48)	(33)
Accrued expenses and other current liabilities	(771)	795
Net cash used in operating activities	(5,271)	(4,661)
Cash flows from investing activities:
Proceeds from sales or maturities of investments	0	7,250
Net cash provided by investing activities	0	7,250
Cash flows from financing activities:
Net (decrease) increase in cash, cash equivalents and restricted cash	(5,271)	2,589
Cash, cash equivalents and restricted cash at beginning of period	17,338	5,219
Cash, cash equivalents and restricted cash at end of period	12,067	7,808
Cash and cash equivalents at end of period	12,042	7,783
Restricted cash at end of period	25	25
Cash, cash equivalents and restricted cash at end of period	12,067	$ 7,808
Supplemental disclosure of non-cash investing and financing activities:
Conversion of Series X preferred stock into common stock shares	$ 44,826