Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 37,265	$ 43,145
Prepaid expenses and other current assets	2,024	2,451
Total current assets	39,289	45,596
Furniture and equipment, net	244	275
Intangible assets	11,148	11,148
Operating lease right-of-use asset	381	403
Total assets	51,062	57,422
Current liabilities:
Accounts payable	1,939	2,095
Accrued expenses and other current liabilities	3,093	2,724
Total current liabilities	5,032	4,819
Operating lease liability - long-term, net of current portion	308	335
Warrant liability - long-term	38	77
Total liabilities	5,378	5,231
Commitments and contingencies (Note 6)
Stockholders' equity
Preferred stock, $0.001 par value; 5,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.001 par value; 100,000,000 shares authorized; 29,600,323 and 28,627,827 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	30	29
Additional paid-in capital	155,396	153,985
Accumulated other comprehensive income	8	12
Accumulated deficit	(109,750)	(101,835)
Total stockholders’ equity	45,684	52,191
Total liabilities and stockholders’ equity	$ 51,062	$ 57,422