Note 4 - Prepaid Expenses and Other - Prepaid Expenses and Other (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
CRO services	$ 431	$ 340
Other clinical development	1,408	2,933
Insurance	2,318	3,178
Professional fees	300	398
Other	1,445	2,135
Total, long-term	5,902	8,984
CRO services	0	166
Other clinical development	0	577
Other	2,069	611
Prepaid Expense and Other Assets, Noncurrent	2,069	1,354
Totals	$ 7,971	$ 10,338