Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Cash Flows From Operating Activities
Net loss	$ (17,992)	$ (16,277)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	967	1,239
Depreciation and amortization	4	18
Other income, net	(1)	(271)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(177)	(474)
Other receivables	42	(10)
Accounts payable and accrued expenses	(2,117)	(107)
Net cash used in operating activities	(19,274)	(15,882)
Cash Flows From Investing Activities
Purchases of marketable securities	0	(6,380)
Maturities of marketable securities	1,000	5,000
Net cash provided by (used in) investing activities	1,000	(1,380)
Cash Flows From Financing Activities
Sale of shares under stock purchase plan	11	18
Payment for tax withholding on vested awards	(16)	(17)
Repurchases of common stock	0	(884)
Net cash used in financing activities	(5)	(883)
Net decrease in cash and cash equivalents	(18,279)	(18,145)
Cash and cash equivalents at beginning of period	35,078	56,007
Cash and cash equivalents at end of period	$ 16,799	$ 37,862