Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (15,894)	$ (17,355)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	164	200
Stock-based compensation	2,373	1,680
Loss from sale of fixed assets	0	6
Change in fair value of warrant liability	(6,728)	(2,346)
Operating lease, net	96	85
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	431	724
Accounts payable	235	(1,024)
Accrued expenses and other current liabilities	372	259
Net cash used in operating activities	(18,951)	(17,771)
Cash flows from investing activities:
Purchase of fixed assets	(19)	(376)
Proceeds from sale of fixed assets	0	2
Net cash used in investing activities	(19)	(374)
Cash flows from financing activities:
Proceeds from exercise of warrants	63	5
Payment of tax liability for vested restricted stock units	(23)	(17)
Proceeds from sale of common stock, net of issuance costs	74,684	22,561
Net cash provided by financing activities	74,724	22,549
Effect of exchange rate changes on cash and cash equivalents	(24)	34
Net change in cash and cash equivalents	55,730	4,438
Cash and cash equivalents, at beginning of year	15,173	10,735
Cash and cash equivalents, at end of year	70,903	15,173
Supplemental disclosures of cash flow information:
Cash paid for interest	0	0
Cash paid for taxes	15	24
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accrued liabilities	5	0
Subscription receivable	$ 0	$ 129