Sumitomo Pharma America announced it will present new clinical data for two investigational blood cancer therapies at the 67th American Society of Hematology (ASH) Annual Meeting & Exposition in Orlando, Florida, from December 6-9, 2025. The presentations will feature updated results for enzomenib, an oral menin inhibitor, and nuvisertib, a PIM1 kinase inhibitor, both targeting difficult-to-treat hematologic malignancies.
Enzomenib Shows Wide Therapeutic Window in AML
Updated clinical data from the ongoing Phase 1/2 study of enzomenib continue to demonstrate promising clinical activity across a wide range of potentially therapeutic doses in patients with relapsed or refractory acute leukemia. The study enrolled 116 patients with KMT2A-rearranged (KMT2Ar), NPM1-mutated (NPM1m), and other HOXA9/MEIS1-driven leukemia subtypes.
In the dose-escalation study, enzomenib was escalated from 40 mg twice daily to 400 mg twice daily with no dose-limiting toxicities observed. Sustained complete remission and complete remission with partial hematologic recovery were seen at doses of 200, 300, and 400 mg twice daily. The wide therapeutic window suggests that dosing may be tailored to the specific biology of different leukemia subtypes for potential optimal therapeutic effect.
Enzomenib is designed to target the menin and mixed-lineage leukemia (MLL) protein interaction, a key interaction for acute leukemia and cell growth in various cancers. In preclinical studies, the drug showed selective growth inhibition in human acute leukemia cell lines with KMT2A rearrangements or NPM1 mutations, while reducing expression of leukemia-associated genes HOXA9 and MEIS1.
Combination Therapy Shows Promise
Preliminary findings from a Phase 1 study of enzomenib in combination with venetoclax and azacitidine (VEN/AZA) in patients with relapsed or refractory AML demonstrate that the combination is well-tolerated up to 300 mg twice daily with no dose-limiting toxicities. The study showed no evidence of significant drug-drug interaction between enzomenib and venetoclax, with promising early clinical activity observed, particularly in patients without prior venetoclax or menin exposure.
Nuvisertib Advances in Myelofibrosis
New clinical data from the Phase 1/2 study evaluating nuvisertib in combination with momelotinib demonstrate early clinical activity in patients with myelofibrosis, with the treatment combination being well-tolerated. Nuvisertib is an oral investigational selective inhibitor of PIM1 kinase that has shown potential antitumor and antifibrotic activity through multiple pathways, including induction of apoptosis in preclinical models.
Findings from the ongoing Phase 1/2 study of nuvisertib monotherapy continue to support that the drug was well-tolerated with no dose-limiting toxicities and notable modulation of cytokine profiles demonstrating a strong correlation with clinical responses. In preclinical studies, nuvisertib alone and in combination with ruxolitinib showed white blood cell and neutrophil count normalization, and also reduced spleen size and bone marrow fibrosis in murine models of myelofibrosis.
Regulatory Recognition and Clinical Need
Both investigational therapies have received significant regulatory recognition. The FDA granted enzomenib Orphan Drug Designation for acute myeloid leukemia in June 2022 and Fast Track Designation for relapsed or refractory AML with MLLr or NPM1m in June 2024. Japan's Pharmaceuticals and Medical Devices Agency granted Orphan Drug Designation for enzomenib in September 2024.
Nuvisertib has received Orphan Drug Designation from the FDA for myelofibrosis in May 2022, Fast Track Designation in June 2025, and Orphan Drug Designation from the European Medicines Agency in July 2025. The Japan Ministry of Health, Labour and Welfare granted Orphan Drug Designation in November 2024.
"Patients living with relapsed/refractory AML or MF desperately need effective therapies to overcome the poor prognoses typically associated with these cancers," said Jatin Shah, M.D., Chief Medical Officer, Oncology, SMPA. "The clinical data are highly compelling, especially for patients with particularly challenging forms of acute leukemia including those with KMT2A-rearranged and NPM1-mutated subtypes."
The company will present three oral presentations and one poster presentation at the ASH meeting, providing more comprehensive data supporting the development of both enzomenib and nuvisertib programs.
