Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net loss	$ (23,155,000)	$ (22,181,000)
Adjustments required to reconcile net loss to net cash used in operating activities:
Depreciation	1,169,000	1,114,000
Gain upon extinguishment of Paycheck Protection Program loan	(722,000)
Stock-based compensation	2,882,000	3,475,000
Non-cash interest expense	60,000	628,000
Payment of accreted interest for deferred consideration for asset acquisition	(586,000)	(432,000)
Changes in operating assets and liabilities:
Award receivable	(2,428,000)	(467,000)
Accounts payable and accrued liabilities	184,000	544,000
Accrued compensation	472,000	(760,000)
Operating lease right-of-use asset and liability, net	499,000	803,000
Prepaid expenses and other current assets	(1,950,000)	(994,000)
Net cash used in operating activities	(23,575,000)	(18,270,000)
Investing activities:
Purchases of property and equipment	(1,304,000)	(824,000)
Net cash used in investing activities	(1,304,000)	(824,000)
Financing activities:
Principal payment of deferred consideration for asset acquisition	(1,414,000)	(568,000)
Proceeds from Paycheck Protection Program Loan		717,000
Proceeds from sale of common stock, net of offering costs	26,319,000	22,893,000
Proceeds from exercise of warrants and stock options	613,000	168,000
Net cash provided by financing activities	25,518,000	23,210,000
Net increase in cash, cash equivalents and restricted cash	639,000	4,116,000
Cash, cash equivalents and restricted cash, beginning of period	10,849,000	6,733,000
Cash, cash equivalents and restricted cash, end of period	11,488,000	10,849,000
Supplemental disclosure of cash flow information:
ROU asset obtained by assuming operating lease liabilities	26,056,000
Paycheck Protection Program loan forgiveness	722,000
Unpaid offering costs	13,000	65,000
Property and equipment included in accounts payable	$ 38,000	$ 150,000