Note 7 - Related party transactions (Details Textual) |
3 Months Ended | 12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
May 06, 2026
USD ($)
|
Apr. 16, 2026
USD ($)
|
Mar. 31, 2026
USD ($)
$ / shares
shares
|
Mar. 31, 2025
USD ($)
|
Dec. 31, 2025
USD ($)
shares
|
Feb. 23, 2026
USD ($)
Advance
|
Nov. 18, 2025
$ / shares
|
Sep. 22, 2025
USD ($)
Advance
|
Jun. 18, 2025
USD ($)
Advance
|
Aug. 27, 2024
USD ($)
|
|
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| Amount received cash equal to shareholder | $ / shares | $ 2.41 | |||||||||
| Common Stock, Shares Outstanding | shares | 2,552,429 | 2,552,429 | ||||||||
| Warrants outstanding | shares | 1,139,085 | |||||||||
| Accrued liabilities | $ 7,349,000 | $ 6,202,000 | ||||||||
| Accounts payable | 3,810,000 | 2,911,000 | ||||||||
| Interest expense, related party | 433,000 | $ 144,000 | ||||||||
| Proceeds from loan payable with related parties | $ 5,850,000 | 0 | ||||||||
| Debt modification description | On February 23, 2026, the Company and Hanmi entered into the Second Amended Facility Agreement, pursuant to which Hanmi provided an additional uncommitted facility ("Facility #3") for up to $11.1 million, administered through multiple advances for the purpose of the continued clinical development of tuspetinib and to fund operations of the Company. Advances under the Second Amended Facility Agreement may be provided in one or more (but no more than six advances) until May 31, 2026. No single advance shall be for an amount in excess of $2.0 million or for an amount that is less than $0.5 million. Additionally, Hanmi may cancel availability under the Second Amended Facility Agreement at any time without notice, acting solely at its discretion. Any amounts repaid under the Second Amended Facility Agreement may not be re-borrowed. As of March 31, 2026, Aptose received a total of $4.0 million under the Second Amended Facility Agreement with additional advances received subsequent to March 31, 2026 (see Note 11). Amounts outstanding pursuant to the Second Amended Facility Agreement, including accrued and unpaid interest, are repayable in full on August 31, 2028. Unpaid principal with respect to each advance shall accrue interest at a rate of 6% per annum.Pursuant to the Second Amended Facility Agreement, the Second Amended Facility Agreement effectively replaced the Hanmi Facility Agreement and Amended Facility Agreement. The Company evaluated whether the Facility #3 transaction resulted in a debt modification or extinguishment to Facility #1 (uncommitted facility pursuant to Hanmi Facility Agreement) and Facility #2 (uncommitted facility pursuant to Amended Facility Agreement) in accordance with ASC 470-50, Debt – Modifications and Extinguishments. The amendments to Facility #1 and Facility #2 were accounted for as a debt modification since the amendment did not result in substantially different terms as the present value of the cash flows pursuant to the revised terms is less than 10% different from the remaining cash flows under the terms of the original agreement. | |||||||||
| Accrued interest on investments | $ (1,300,000) | $ (900,000) | ||||||||
| Hanmi Loan Agreement [Member] | ||||||||||
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| Loan agreement amount | $ 10,000,000 | |||||||||
| Interest expense | 400,000 | 100,000 | ||||||||
| Interest expense paid | $ 0 | $ 0 | ||||||||
| Hanmi Facility Agreement [Member] | ||||||||||
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| Loan agreement amount | $ 11,100,000 | $ 11,900,000 | $ 8,500,000 | |||||||
| Maximum number of advances | Advance | 6 | 8 | 5 | |||||||
| Maximum amount available under single advance | $ 2,000,000 | $ 2,000,000 | $ 2,500,000 | |||||||
| Minimum amount available under single advance | 500,000 | $ 500,000 | ||||||||
| Hanmi Facility Agreement [Member] | Subsequent Event [Member] | ||||||||||
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| Additional proceeds from related party debt | $ 2,000,000 | $ 1,100,000 | ||||||||
| Proceeds from loan payable with related parties | $ 7,100,000 | |||||||||
| Hanmi Second Amended Facility Agreement [Member] | ||||||||||
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| Loan agreement amount | $ 11,100,000 | |||||||||
| Loan interest rate | 6.00% | |||||||||
| Maximum number of advances | Advance | 6 | |||||||||
| Maximum amount available under single advance | $ 2,000,000 | |||||||||
| Minimum amount available under single advance | $ 500,000 | |||||||||
| Proceeds from loan payable with related parties | $ 4,000,000 | |||||||||
| Debt modification description | Pursuant to the Second Amended Facility Agreement, the Second Amended Facility Agreement effectively replaced the Hanmi Facility Agreement and Amended Facility Agreement. The Company evaluated whether the Facility #3 transaction resulted in a debt modification or extinguishment to Facility #1 (uncommitted facility pursuant to Hanmi Facility Agreement) and Facility #2 (uncommitted facility pursuant to Amended Facility Agreement) in accordance with ASC 470-50, Debt – Modifications and Extinguishments. The amendments to Facility #1 and Facility #2 were accounted for as a debt modification since the amendment did not result in substantially different terms as the present value of the cash flows pursuant to the revised terms is less than 10% different from the remaining cash flows under the terms of the original agreement. | |||||||||
| Repayment date | Aug. 31, 2028 | |||||||||
| Hanmi Pharmaceuticals Co., Ltd. [Member] | ||||||||||
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| Number of common shares held | shares | 508,710 | |||||||||
| Common share exchange price | $ / shares | $ 51.3 | |||||||||
| Investment Owned, Balance, Shares | shares | 508,710 | |||||||||
| Warrants to purchase common shares, number of warrants | shares | 77,972 | |||||||||
| Maximum [Member] | ||||||||||
| Schedule of Equity Method Investments [Line Items] | ||||||||||
| cash flows pursuant to the revised | 10.00% | |||||||||