Note 1 - Organization and Nature of Business (Details Textual) $ / shares in Units, $ in Thousands		1 Months Ended		6 Months Ended
	Sep. 15, 2021 USD ($)	Jun. 30, 2024 USD ($) $ / shares shares	Jan. 31, 2024 USD ($) $ / shares shares	Jun. 30, 2024 USD ($) $ / shares shares	Jun. 30, 2023 USD ($)
Number of Reportable Segments				1
June 2024 Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		50,000,000
Shares Issued, Price Per Share (in dollars per share) | $ / shares		$ 0.8		$ 0.8
Proceeds from Issuance or Sale of Equity		$ 40,000
Proceeds from Issuance of Common Stock		$ 37,600		$ 37,555	$ 0
RA Capital Healthcare Fund 2024 [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares			15,384,615
Shares Issued, Price Per Share (in dollars per share) | $ / shares			$ 0.65
Proceeds from Issuance of Common Stock			$ 9,900	$ 9,945	$ 0
Gross Proceeds from Issuance of Common Stock			$ 10,000
The September 2021 ATM [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares				7,719,641
Proceeds from Issuance or Sale of Equity				$ 9,100
Proceeds from Issuance of Common Stock				$ 8,800
Open Market Sale Agreement, Maximum Aggregate Offering Price	$ 100,000
Open Market Sale Agreement, Sales Commission, Percentage	3.00%