Ziftomenib in combination with venetoclax and azacitidine in newly diagnosed NPM1-m acute myeloid leukemia: Phase 1b results from KOMET-007

Abstract Introduction: Nucleophosmin 1 mutations (NPM1-m) drive leukemogenesis in approximately 30% of acute myeloid leukemia (AML) cases. Ziftomenib is a potent, highly selective, oral, investigational menin inhibitor that has demonstrated clinical activity as both monotherapy and in combination for adults with NPM1-m or lysine methyltransferase 2A-rearranged (KMT2A-r) AML. KOMET-007 (NCT05735184) is an ongoing, open-label, dose-escalation (phase 1a) and expansion (phase 1b) study of ziftomenib in combination with standard chemotherapies in NPM1-m or KMT2A-r AML. Here we present phase 1b safety and clinical activity in patients with newly diagnosed NPM1-m AML who received the recommended phase 2 dose (RP2D) of ziftomenib 600 mg in combination with venetoclax and azacitidine (Ven/Aza). Methods: Adults (≥18 years) with newly diagnosed NPM1-m AML who were not eligible for intensive chemotherapy were enrolled in phase 1b and received ziftomenib 600 mg once daily plus standard doses of Ven/Aza. Ziftomenib was orally administered once daily continuously from Cycle 1 Day 8 onward. Phase 1b primary endpoints were adverse events (AEs) and complete remission (CR) per ELN 2022. Secondary endpoints included composite CR (CRc; defined as CR with full, partial, or incomplete hematologic recovery), overall response, and duration of response. Local measurable residual disease (MRD) was assessed by next-generation sequencing, RT-qPCR, and multiparameter flow cytometry. Results: As of June 25, 2025, 39 patients with newly diagnosed NPM1-m AML were enrolled and treated with ziftomenib 600 mg once daily plus Ven/Aza in phase 1b. Median age was 75 years (range 53–93), 54% were female, 46% had ECOG PS 0–1; 12 (31%) had FLT3 co-mutations and 9 (23%) had IDH co-mutations. Median duration of follow-up was 16.3 weeks (range 1.6–41.1). Twenty-nine patients (74%) had grade ≥3 treatment-emergent AEs, most commonly (≥20% of patients) decreased neutrophil count (31%) and decreased platelet count (23%). Grade ≥3 ziftomenib-related AEs occurred in 14 patients (36%), most commonly decreased neutrophil count (15%) and decreased platelet count (13%). No ziftomenib treatment discontinuations occurred due to AEs. Differentiation syndrome occurred in 1 (3%) patient (grade 2), which successfully resolved with protocol-specified mitigation. One patient (3%) had investigator-assessed ziftomenib-associated QTc prolongation (grade 3); however, there were concomitant significant electrolyte abnormalities and event resolved with electrolyte repletion. At time of data cutoff, 31 NPM1-m patients were response-evaluable (≥1 response assessment or death). CRc rate was 84% (26/31) after a median time to first CRc of 3.5 weeks (range 2.4–9.4), with local MRD-negativity rates among tested CRc responders of 54% (13/24) after a median time to first MRD-negativity of 8.4 weeks (range 2.9–17.4). CR rate was 58% (18/31) and overall response rate was 94% (29/31), with responses and MRD-negativity rates continuing to evolve. During continuous ziftomenib administration in patients who achieved CRc, median time to neutrophil recovery (≥1×109/L) was 36 days, and median time to platelet recovery (≥100×109/L) was 28 days. The median duration of response and median overall survival were not reached as of the data cutoff, at a median follow-up of 16.3 weeks. The study is ongoing, with 81% (25/31) of NPM1-m patients still on-study and 77% (24/31) still on ziftomenib treatment. Updated safety and clinical activity results will be presented.Conclusions: In the ongoing KOMET-007 study, ziftomenib RP2D of 600 mg once daily combined with Ven/Aza was well tolerated and demonstrated robust clinical activity in patients with newly diagnosed NPM1-m AML, including 84% CRc after a median of 3.5 weeks and 54% CRc MRD-negativity after a median of 8.4 weeks. Low rates of ziftomenib-related cytopenia and no additional myelosuppression were observed with this combination. One case each of differentiation syndrome (grade 2) and investigator-assessed QTc (grade 3) were successfully resolved. Taken together, these data support the RP2D determination and advancement of this ziftomenib-based combination in the KOMET-017 (NCT07007312) randomized phase 3 study in patients with newly diagnosed NPM1-m AML.