Note 1 - Organization and Nature of Business (Details Textual) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Sep. 15, 2021 USD ($)	Jan. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($)
Number of Reportable Segments			1
RA Capital Healthcare Fund 2024 [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		15,384,615	15,384,615
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 0.65	$ 0.65
Gross Proceeds from Issuance of Common Stock		$ 10,000	$ 10,000
Net Proceeds From Issuance of Common Stock		$ 9,900	9,900
Proceeds from Issuance of Common Stock			$ 9,945	$ 0
The September 2021 ATM [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares			7,404,672
Open Market Sale Agreement, Maximum Aggregate Offering Price	$ 100,000
Open Market Sale Agreement, Sales Commission, Percentage	3.00%
Proceeds from Issuance of Common Stock			$ 8,700
Proceeds from Issuance of Common Stock, Net			$ 8,400