Quarterly report [Sections 13 or 15(d)]

Note 10 - Related party transactions (Details Textual)

v3.25.2
Note 10 - Related party transactions (Details Textual)
 6 Months Ended 44 Months Ended
Aug. 04, 2025
USD ($)
Jul. 15, 2025
USD ($)
Jun. 20, 2025
USD ($)
Jun. 18, 2025
USD ($)
Advance
Jun. 17, 2025
USD ($)
Mar. 18, 2025
USD ($)
$ / shares
shares
Sep. 02, 2024
USD ($)
Aug. 27, 2024
USD ($)
Jan. 30, 2024
USD ($)
$ / shares
shares
Sep. 06, 2023
USD ($)
shares
Nov. 04, 2021
USD ($)
shares
Jun. 30, 2025
USD ($)
$ / shares
shares
Jun. 30, 2024
USD ($)
Jun. 30, 2025
USD ($)
$ / shares
shares
Dec. 31, 2024
USD ($)
shares
Sep. 30, 2024
Aug. 10, 2023
USD ($)
Schedule of Equity Method Investments [Line Items]                                  
Common Stock, Shares Outstanding | shares                       2,552,429   2,552,429 2,006,028    
Warrants outstanding | shares                       1,267,585   1,267,585 1,267,585    
Accrued liabilities                       $ 5,414,000   $ 5,414,000 $ 2,773,000    
Accounts payable                       2,879,000   2,879,000 1,258,000    
Proceeds from loan payable with related parties                       2,600,000 $ 0        
Short-Term Advance from CEO [Member] | CEO [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Loan is repayable date         Jun. 17, 2025                        
Proceeds from loan payable with related parties         $ 100,000                        
Short-Term Advance                       0   0      
Public Offering [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Common shares issued (in shares) | shares                 188,304                
Over-Allotment Option [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Common shares issued upon exercise of stock options                 $ 24,561                
Shares Issued, Price Per Share | $ / shares                 $ 51.3                
Common Shares [Member] | Public Offering [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Warrants to purchase common shares, number of warrants | shares                 188,174                
Supply Agreement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Expenses                       0 0 7,100,000      
Accrued liabilities                             $ 0    
Accounts payable                       0   $ 0      
Tuspetinib Licensing Agreement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
License Fee, Total                     $ 12,500,000            
Payments for License Fee                     5,000,000            
Stock Issued During Period, Value, Licensing Fee                     $ 7,500,000            
Hanmi Loan Agreement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Loan agreement amount               $ 10,000,000                  
Loan is repayable date               Jan. 31, 2027                  
Interest expense                       300,000          
Interest expense paid                       0          
Loan interest rate                               6.00%  
Convertible debt conversion             $ 8,500,000                    
Hanmi Facility Agreement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Loan agreement amount       $ 8,500,000                          
Loan is repayable date       Jun. 18, 2025                          
Interest expense                       4,000          
Interest expense paid                       $ 0          
Loan interest rate                       6.00%   6.00%      
Maximum number of advances | Advance       5                          
Maximum amount available under single advance       $ 2,500,000                          
Initial proceeds from related party debt     $ 2,500,000                            
Proceeds from loan payable with related parties $ 5,600,000                                
Repayment date       Aug. 31, 2028                          
Interest payments frequency                       three-month          
Hanmi Facility Agreement [Member] | Subsequent Event [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Additional proceeds from related party debt 1,100,000 $ 2,000,000                              
Proceeds from loan payable with related parties $ 5,600,000                                
Debt Conversion Agreement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Shares Issued, Price Per Share | $ / shares           $ 3.7                      
Debt conversion, description                       Additionally, pursuant to the Debt Conversion Agreement, the Company and Hanmi agreed that the interest payment associated with the period from December 21, 2024 through March 31, 2025 (the "First Deferred Interest Period") may be deferred and made on or before the final closing date of a financing, not including the amount being converted pursuant to the Debt Conversion Agreement, totaling $15.0 million ("Capital Raise"), but no later than June 27, 2025. On June 24, 2025, the Company and Hanmi entered into an Interest Payment Agreement whereby the interest due for the First Deferred Interest Period and interest associated with the period from March 31, 2025 through June 30, 2025 (the "Second Deferred Interest Period") may be deferred and made no later than December 31, 2025. Further, pursuant to the Debt Conversion Agreement, Hanmi, at its sole discretion, can opt to convert the remaining indebtedness amount, or a portion thereof, to Aptose common shares upon the successful completion of the Capital Raise, provided that the amount of Aptose common shares delivered to Hanmi pursuant to such subsequent conversion shall not cause Hanmi to own more than 19.99% of the Company.          
Capital raise, amount           $ 15,000,000                      
Convertiable debt amount           $ 1,500,000                      
Common shares converted | shares           409,063                      
Hanmi Pharmaceuticals Co., Ltd. [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Number of common shares held | shares                     7,190 508,710   508,710      
Future milestone payments                     $ 407,500,000            
Proceeds from Issuance of Common Stock                   $ 3,000,000              
Shares Issued, Price Per Share | $ / shares                       $ 51.3   $ 51.3      
Investment Owned, Balance, Shares | shares                     7,190 508,710   508,710      
Warrants to purchase common shares, number of warrants | shares                       77,972   77,972      
Payment of supply costs                       $ 0 $ 2,600,000        
Hanmi Pharmaceuticals Co., Ltd. [Member] | Public Offering [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Premium share price (as a percent)                 11.00%                
Hanmi Pharmaceuticals Co., Ltd. [Member] | Private Placement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Common shares issued (in shares) | shares                 70,175                
Shares Issued, Price Per Share | $ / shares                 $ 57                
Hanmi Pharmaceuticals Co., Ltd. [Member] | Common Shares [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Number of shares sold | shares                   22,281              
Hanmi Pharmaceuticals Co., Ltd. [Member] | Common Shares [Member] | Private Placement [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Warrants to purchase common shares, number of warrants | shares                 77,972                
Maximum [Member] | Hanmi Pharmaceuticals Co., Ltd. [Member]                                  
Schedule of Equity Method Investments [Line Items]                                  
Investment for ownership interest                                 $ 7,000,000
Percentage of investment                                 19.99%