Aptose Biosciences announces clinical data on tuspetinib

Aptose Biosciences (APTO) featured a wealth of clinical data for Aptose’s lead compound tuspetinib in a poster presentation at the 66th American Society of Hematology Annual Meeting in San Diego. Poster title: “Phase 1 Safety and Efficacy of Tuspetinib Plus Venetoclax Combination Therapy in Study Participants with Relapsed or Refractory Acute Myeloid Leukemia Support Exploration of Triplet Combination Therapy of Tuspetinib Plus Venetoclax and Azacitidine for Newly Diagnosed AML” Key Findings and Messages: TUS+VEN+AZA triplet trial is proceeding in newly diagnosed AML patients. TUS+VEN retains activity in the difficult-to-treat prior-VEN AML population. TUS+VEN is active in FLT3 wildtype, representing ~70% of AML patients. TUS+VEN is well tolerated and can be safely co-administered. TUS+VEN is active across broad populations of R/R AML. Combination of TUS with VEN may avoid VEN resistance. TUS+VEN+AZA triplet may establish a more effective, mutation agnostic standard of care for chemotherapy ineligible AML patients. Tuspetinib, being developed by Aptose and originally created by Hanmi Pharmaceutical Co., is being advanced as the TUS+VEN+AZA triplet for frontline therapy of newly diagnosed AML patients ineligible for intensive chemotherapy. TUS is a once daily, oral, multi-kinase inhibitor selectively targeting kinases that drive AML cell proliferation. In the Phase 1/2 APTIVATE trial of relapsed/refractory AML patients, TUS single agent and the TUS+VEN doublet demonstrated excellent safety and broad efficacy across AML genetic subgroups – including those with adverse mutations in TP53 and RAS genes, and those with mutated or unmutated FLT3 genes. Highlights of the ASH poster presentation: TUS as Single Agent: 60% and 42% CR/CRh with 80 mg TUS in FLT3 mutated and all-comer VEN-naive AML 33% CRc & 42% ORR in FLT3 mutated and VEN-naive patients. Includes 40, 80, 120, and 160 mg TUS dose as a single agent. Includes those who failed prior therapy with venetoclax. Includes those with mutated or unmutated FLT3, those who failed prior-HSCT, priorFLT3i, prior-chemotherapy, prior-HMA. TUS once daily orally as a single agent achieved CR/CRh responses at four different dose levels with no dose limiting toxicities. TUS showed a favorable safety profile with no DLTs through 160 mg per day, and no drug related discontinuations, no QTc, no differentiation syndrome, and no deaths. TUS/VEN Combination Therapy: 40% ORR with 80 mg TUS + 400 mg VEN in FLT3 mutated patients. Among these 83% had failed prior-VEN treatment and 50% had failed both prior-VEN and FLT3i treatment. TUS+VEN achieved responses among diverse R/R AML with adverse mutations in VEN-naive, prior-VEN, FLT3WT, FLT3MUT, prior-FLT3. TUS+VEN showed favorable safety and tolerability with no new or unexpected safety signals, no drug related CPK elevations, no differentiation syndrome, and no deaths