Condensed Consolidated Statements of Cash Flows - USD ($)	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (12,100,000)	$ (17,146,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	17,000	55,000
Stock-based compensation	840,000	789,000
Expense from restricted stock units	411,000	0
Accretion of discount and amortization of premiums on marketable securities	(3,000)	7,000
Amortization of deferred financing costs	888,000	0
Change in fair value of derivative warrant liabilities	2,000	0
Non-cash lease expense	100,000	200,000
Gain on disposals	(16,000)	0
Changes in current assets and liabilities:
Prepaid expenses and other current assets	1,182,000	82,000
Other assets	41,000	(104,000)
Accounts payable	(2,005,000)	2,058,000
Accrued expenses	(17,000)	(865,000)
Deferred revenue	1,003,000	991,000
Lease liabilities	(106,000)	(209,000)
Net cash used in operating activities	(9,763,000)	(14,142,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	0	(43,000)
Sales of property and equipment	150,000	0
Purchases of marketable securities	0	(14,985,000)
Sales of marketable securities	2,000,000	17,947,000
Net cash provided by investing activities	2,150,000	2,919,000
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from private offering	2,791,000	0
Payments of transaction costs	(616,000)	(649,000)
Proceeds from issuances of common stock under equity stock purchase plan	5,000	0
Proceeds from exercise of stock options	0	73,000
Net cash provided by (used in) financing activities	2,180,000	(576,000)
Net decrease in cash and cash equivalents	(5,433,000)	(11,799,000)
Cash and cash equivalents, beginning of period	14,802,000	23,443,000
Cash and cash equivalents, end of period	9,369,000	11,644,000
Supplemental disclosure of non-cash investing and financing activities:
Transaction costs in accounts payable and accrued liabilities at period end	43,000	1,582,000
Reclassification of private warrants	$ 13,000	$ 0