Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 32,172	$ 43,145
Prepaid expenses and other current assets	3,208	2,451
Total current assets	35,380	45,596
Furniture and equipment, net	229	275
Intangible assets	11,148	11,148
Operating lease right-of-use asset	358	403
Total assets	47,115	57,422
Current liabilities:
Accounts payable	4,136	2,095
Accrued expenses and other current liabilities	2,418	2,724
Total current liabilities	6,554	4,819
Operating lease liability - long-term, net of current portion	291	335
Warrant liability - long-term	2	77
Total liabilities	6,847	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; 29,789,322 and 28,627,827 shares issued and outstanding at June 30, 2023 and December 31, 2022, respectively	30	29
Additional paid-in capital	155,957	153,985
Accumulated other comprehensive income	7	12
Accumulated deficit	(115,726)	(101,835)
Total stockholders’ equity	40,268	52,191
Total liabilities and stockholders’ equity	$ 47,115	$ 57,422