v3.26.1
Note 3 - Investments and Agreements (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Feb. 02, 2026
Feb. 18, 2025
Jan. 08, 2025
Jan. 08, 2024
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Aug. 13, 2024
Mar. 31, 2024
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Common stock, par value         $ 0.001     $ 0.001   $ 0.001    
Other income from a related party         $ 0 $ 0   $ 0 $ 1,400,000      
2024 At-the-Market (ATM) Agreement [Member]                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Agent commission fee as a percentage of gross sales price                     3.00%  
Stock issued during period, shares   3,379,377                    
Stock purchase price per share   $ 3.02                    
Proceeds from issuance of common stock   $ 10,200,000                    
2024 At-the-Market (ATM) Agreement [Member] | Common Stock [Member]                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Stock issued during period, shares [1]             3,379,377          
Maximum amount of securities offer and sell                     $ 250,000,000  
Lantheus Investment Agreement                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Stock issued during period, shares       5,634,235                
Investment agreement, contingent amount of gross proceeds raised       $ 50,000,000                
Percent of outstanding shares       19.99%                
Lantheus Investment Agreement | Option Agreement [Member]                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Percent of outstanding shares                       19.90%
Other income from a related party     $ 1,400,000                  
One-time payment received for rights granted       $ 28,000,000                
Repayment provisions       $ 0                
Piper Sandler & Co. and UBS Securities LLC [Member] | Underwriting Agreement [Member] | Two Thousand Twenty Six Pre-funded Warrants [Member]                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Warrants to purchase shares of common stock 6,598,046                      
Warrant exercise price per share $ 3.789                      
Shares and warrants, price difference per share $ 0.001                      
Gross proceeds from public offering $ 175,000,000                      
Percentage of ownership considered for warrant exercise 4.99%                      
Percentage of ownership considered for warrant exercise 9.99%                      
Maximum increase or decrease in ownership percentage 19.99%                      
Piper Sandler & Co. and UBS Securities LLC [Member] | Two Thousand Twenty Six Offering [Member] | Underwriting Agreement [Member]                        
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]                        
Stock issued during period, shares 39,576,088                      
Sale of stock, price per share $ 3.79                      
[1]

1. See Note 3, Investments and Agreements, for additional information.