Aptose Biosciences Inc. is advancing the development of tuspetinib, an oral kinase inhibitor, as a potential game-changer in triplet therapy regimens for acute myeloid leukemia (AML). The company recently announced a $10 million loan from Hanmi Pharmaceutical Co. to support the clinical development of tuspetinib and is actively negotiating a co-development collaboration agreement.
Tuspetinib has demonstrated broad clinical activity in AML patients with diverse mutation profiles, including those with adverse genetics, as observed in the APTIVATE trial. William G. Rice, Ph.D., Chairman, President and Chief Executive Officer of Aptose, stated that tuspetinib's breadth of activity and unique safety profile make it a promising candidate for triplet therapy.
Tuspetinib's Potential in Triplet Therapy
Triplet therapies building on the standard of care in AML have shown higher response rates but are often limited to specific subpopulations and can cause myelosuppression and other toxicities. Tuspetinib targets SYK, FLT3, mutated KIT, JAK1/2, and RSK2 kinases, while avoiding many typical toxicities associated with other agents. In the APTIVATE trial, tuspetinib achieved broad activity as a single agent and in combination with venetoclax in relapsed/refractory and heavily pre-treated AML populations. Responses were observed in patients with prior venetoclax, FLT3 inhibitor, and HSCT therapies, as well as those with TP53 and RAS gene mutations.
Aptose plans to initiate a triplet combination study during the quarter, treating newly diagnosed AML patients ineligible for induction chemotherapy, irrespective of their FLT3 mutation status. This study will combine tuspetinib with venetoclax and a hypomethylating agent. The company is also evaluating other co-development opportunities to expand tuspetinib's role in other settings.
Financial Status and Nasdaq Compliance
Aptose is addressing compliance with Nasdaq listing requirements, including the minimum stockholders’ equity and minimum bid price per share. The company has a hearing scheduled for November 21, 2024, to appeal Nasdaq's determination of non-compliance with the Stockholders’ Equity Requirement. Aptose has until January 13, 2025, to regain compliance with the Minimum Bid Price Requirement.
As of September 30, 2024, Aptose's cash and cash equivalents totaled $8 million. The company anticipates that its available capital will be sufficient to fund planned operations, including research and development, through January 2025.
Upcoming Milestones
Aptose anticipates several value-creating milestones, including:
- Initiating dosing of the tuspetinib, venetoclax, and azacitidine triplet in newly diagnosed AML patients in Q4 2024.
- Completing the Hanmi/Aptose collaboration agreement by year-end 2024.
- Reporting complete remission (CR) and safety data from the APTIVATE tuspetinib and venetoclax doublet study at ASH 2024.
- Reporting dosing accrual from the tuspetinib, venetoclax, and azacitidine triplet study at ASH 2024.
- Enrolling two dose cohorts in the triplet study in the first half of 2025.
- Reporting CR, MRD, and safety data from the triplet study in the first half of 2025.
- Selecting the tuspetinib dose for Phase 2/3 pivotal trials at ASH 2025.
