Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (24,973)	$ (9,705)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation	2,609	3,439
Depreciation and amortization expense	11	105
Change in fair value of warrant and private placement derivative liabilities	(1,964)	(15,126)
Loss on dispositions, net	0	478
Amortization of right-of-use assets	0	33
Accretion of lease liability	0	23
Changes in operating assets and liabilities:
Accounts receivable, interest and other receivables	205	170
Prepaid expenses and other assets	(695)	(462)
Accounts payable	396	(801)
Accrued liabilities and other	(1,372)	(1,260)
Net cash used in operating activities	(25,783)	(23,106)
Cash flows from investing activities:
Proceeds from sale of property and equipment	0	900
Purchases of property and equipment	(21)	(7)
Net cash provided by (used in) investing activities	(21)	893
Cash flows from financing activities:
Proceeds from issuance of pre-funded warrants, net	0	32,908
Payment on financing lease obligations	0	(35)
Net cash provided by financing activities	0	32,873
Effect of exchange rate changes on cash	(16)	1
Net change in cash, cash equivalents and restricted cash	(25,820)	10,661
Cash, cash equivalents and restricted cash at beginning of period	47,657	36,996
Cash, cash equivalents and restricted cash at end of period	$ 21,837	$ 47,657