Note 6 - Prepaid Expenses - Schedule of Prepaid Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Prepaid research and development	$ 2,832	$ 3,480
Prepaid insurance	158	387
Professional services	362	130
Other	120	34
Total prepaid expenses	$ 3,472	$ 4,031