Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (42,193)	$ (22,333)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	435	337
Stock-based compensation expense	2,251	2,128
Issuance of common stock for licensing activities	6,460
Issuance of shares in exchange for consulting services	33
Gain on extinguishment of Paycheck Protection Program loan	(722)
Non-cash debt issuance expense	250
Change in fair value of note payable	33
Share of loss from equity method investment		9
Changes in operating assets and liabilities:
Other receivables	131	(144)
Prepaid asset	178	808
Contract costs		(488)
Other assets	56	46
Accounts payable	2,654	(83)
Accrued liabilities and other liabilities	5,349	(756)
Deferred revenue	2,149
Net cash used in operating activities	(22,936)	(20,476)
Cash flows from investing activities:
Purchase of property and equipment	(530)	(367)
Net cash used in investing activities	(530)	(367)
Cash flows from financing activities:
Proceeds from note payable	5,000	715
Proceeds from issuance of common stock and warrants, net	29,715	7,949
Proceeds from stock option exercises	5	14
Net cash provided by financing activities	34,720	8,678
Net increase (decrease) in cash, cash equivalents and restricted cash	11,254	(12,165)
Cash, cash equivalents and restricted cash at:
Beginning of period	8,732	20,897
End of period	19,986	8,732
Supplemental cash flow disclosures:
Cash paid for taxes	2	2
Property and equipment additions		$ 230
Supplemental noncash investing and financing activities:
Financed insurance premiums, net	696
Deemed dividends	$ 4,127