Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities:
Net loss	$ (3,325)	$ (2,969)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	16	14
Reduction in the carrying amount of right-of-use assets	71	135
Share-based compensation	319	416
Changes in operating assets and liabilities:
Accounts receivable	(179)	42
Prepaid expenses and other current assets	57	57
Other receivable due from related party	0	(5)
Accounts payable	257	99
Accrued liabilities and other current liabilities	(201)	(23)
Deferred revenue	101	497
Operating lease liability	(29)	(146)
Net cash used in operating activities	(2,913)	(1,883)
Investing activities:
Purchase of property and equipment	(29)	(27)
Net cash used in investing activities	(29)	(27)
Financing activities:
Proceeds from sales of common stock	0	2,000
Proceeds from exercise of common stock options	0	5
Net cash provided by financing activities	0	2,005
Net change in cash and cash equivalents	(2,942)	95
Cash and cash equivalents at beginning of period	12,872	21,407
Cash and cash equivalents at end of period	9,930	21,502
Supplemental disclosure of noncash investing and financing activities:
Unpaid issuance costs of common stock	$ 0	$ 66