Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 10,845	$ 23,550
Prepaid expenses and other current assets	2,886	2,723
Total current assets	13,731	26,273
Furniture and equipment, net	221	272
Intangible assets	11,148	11,148
Operating lease right-of-use asset	475	524
Total assets	25,575	38,217
Liabilities, Current [Abstract]
Accounts payable	2,833	2,498
Accrued expenses and other current liabilities	2,913	4,317
Total current liabilities	5,746	6,815
Operating lease liability - long-term, net of current portion	420	474
Warrant liability - long-term	1,704	4,855
Total liabilities	7,870	12,144
Commitments and contingencies (Note 7)
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; 2,560,785 and 2,227,516 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively	3	33
Additional paid-in capital	158,605	157,653
Accumulated other comprehensive loss	(10)	(9)
Accumulated deficit	(140,893)	(131,604)
Total stockholders’ equity	17,705	26,073
Total liabilities and stockholders’ equity	$ 25,575	$ 38,217