Note 3 - Accrued Expenses and Other Current Liabilities - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accrued research and development	$ 1,035	$ 1,005
Accrued payroll and bonuses	869	606
Accrued legal, regulatory, professional and other	505	442
Accrued liabilities due to related party	124	109
Total accrued expenses and other current liabilities	2,610	2,258
Accounts Payable and Accrued Liabilities [Member]
Operating lease liability - current	$ 77	$ 96