SUMMARY: The FDA on November 13, 2025, approved Ziftomenib (KOMZIFTI®), a menin inhibitor, for adults with relapsed or refractory Acute Myeloid Leukemia (AML) with a susceptible Nucleophosmin 1 (NPM1) mutation who have no satisfactory alternative treatment options.
The American Cancer Society estimates that in 2025, 22,010 new cases of Acute Myeloid Leukemia (AML) will be diagnosed in the United States and 11,090 patients will die of the disease. AML is one of the most common types of leukemia in adults and can be considered as a group of molecularly heterogeneous diseases with different clinical behavior and outcomes. With the understanding of molecular pathology of AML, personalized and targeted therapies are becoming an important part of the AML treatment armamentarium.
NPM1 mutations present in up to 30% of newly diagnosed adult AML define a unique disease subset recognized by both the WHO and the International Consensus Classification. Although NPM1-mutated AML often responds well to initial intensive therapy, outcomes deteriorate sharply after relapse or refractory disease. Patients in this setting frequently face limited therapeutic options and dismal response rates with conventional salvage strategies.
Mounting evidence shows that NPM1-mutated and KMT2A-rearranged (KMT2A-r) leukemias rely on an aberrant transcriptional program maintained through the interaction between menin and KMT2A. This dependency includes pathologic overexpression of HOX and MEIS1, which reinforce leukemic self-renewal and block differentiation. Inhibiting the menin–KMT2A complex has therefore emerged as a compelling therapeutic strategy capable of reversing leukemic transcriptional programs.
Ziftomenib, a potent and selective oral menin inhibitor, disrupts this interaction and restores myeloid differentiation in preclinical models. The registrational Phase II portion of the KOMET-001 study provides the most definitive evidence to date of its clinical potential in relapsed/refractory NPM1-mutated AML, and was used for the primary efficacy analysis and formed the basis for the FDA approval.
Mechanistic Rationale for Menin Inhibition
Menin serves as a scaffold protein essential for recruitment of the KMT2A/MLL methyltransferase complex to chromatin. This interaction drives leukemogenic transcriptional circuits in both KMT2A-r and NPM1-mutated AML, promoting expression of HOXA9, MEIS1, PBX3, and downstream effectors such as FLT3 and BCL2.
Key mechanistic insights include:
- Menin–KMT2A blockade releases mutant NPM1 from chromatin, reducing HOX/MEIS1 signaling and triggering differentiation.
- Ziftomenib promotes terminal maturation of AML blasts, rather than direct cytotoxicity, consistent with its differentiation-based mechanism.
- NPM1 cytoplasmic mislocalization, a hallmark of the mutation, creates vulnerabilities that can be exploited through menin inhibition and related targeted approaches.
This biology underpins the therapeutic activity observed in KOMET-001 and supports the broader pursuit of menin inhibition across multiple AML subtypes.
KOMET-001 Trial Overview
KOMET-001 is a global, multicenter Phase I/II study evaluating single-agent Ziftomenib in adults with relapsed/refractory NPM1-mutated or KMT2A-rearranged AML. The Phase II portion which serves as the registrational dataset, focused on patients with relapsed/refractory NPM1-mutated disease treated at the recommended monotherapy dose of Ziftomenib 600 mg once daily.
Among the 92 patients with relapsed/refractory NPM1-mutated AML included in Phase II:
- Median age: 69 years (range 33–84); 64% were ≥65 years
- Median prior therapies: 2 lines (range 1–7)
- Prior venetoclax exposure: 59%
- Prior allogeneic transplantation: 24%
- Common co-mutations: FLT3 (56%), IDH1/2 (33%)
- ECOG 0–1: 83%
Efficacy was established based on the rate of Complete Remission (CR) plus CR with partial hematological recovery (CRh), the duration of CR plus CRh, and the rate of conversion from transfusion dependence to transfusion independence. The median follow-up was 4.2 months.
This heavily pretreated population reflects real-world patients with few remaining therapeutic options and particularly poor expected outcomes.
Efficacy Findings
Ziftomenib met its Primary endpoint with a CR/CRh rate of 22% (95% CI 14–32; P=0.0058), exceeding the historical 12% benchmark for this setting.
Key efficacy results:
- CR/CRh rate: 22% (14% CR; 8% CRh)
- Composite CR rate: 26%
- Overall Response Rate (ORR): 33%
- Median time to first response: 1.9 months
- Median duration of response: 4.6 months
- MRD negativity: 61% of evaluable CR/CRh responders
- Median Overall Survival (OS): 6.6 months
- Median OS among responders: 18.4 months
Two responders were successfully bridged to allogeneic stem cell transplantation and resumed Ziftomenib maintenance afterwards.
Efficacy was maintained across clinically relevant subgroups:
- Age <65 vs ≥65: 21% vs 22% CR/CRh
- Prior venetoclax exposure: 22% CR/CRh
- Prior HSCT: 23% CR/CRh
- FLT3 co-mutations: 13% (ITD), 33% (TKD)
- IDH1/2 co-mutations: 50% and 31%, respectively
The activity in Venetoclax-exposed patients is particularly noteworthy given real-world salvage CR rates as low as 4% in this population.
Transfusion Independence
- RBC independence conversion: 23%
- Platelet independence conversion: 15%
- Overall transfusion independence conversion: 20%
These improvements reflect meaningful clinical benefit and enhanced quality of life.
Safety and Tolerability
Ziftomenib demonstrated a favorable safety profile with low rates of treatment-related discontinuation (3%). Most adverse events were consistent with underlying AML or expected from differentiation-based therapies. Common Grade ≥3 TEAEs included febrile neutropenia (26%), anemia (20%) and thrombocytopenia (20%). Differentiation Syndrome occurred in 25% (15% grade 3; none grade 4–5) managed effectively using protocol-defined measures including cytoreduction and steroid prophylaxis, reinforcing the necessity of early recognition and continued therapy through differentiation-associated changes. Overall, ziftomenib showed no clear intrinsic myelosuppression, minimal cardiac toxicity, and a manageable safety profile appropriate for a predominantly older patient population.
Clinical Implications
The KOMET-001 data establish Ziftomenib as a meaningful therapeutic advance for patients with relapsed/refractory NPM1-mutated AML, an area historically characterized by low response rates and short survival. The durability of responses, high rate of MRD clearance, and consistent efficacy across age groups, co-mutational backgrounds, and prior therapies position Ziftomenib as a valuable monotherapy option and a potential bridge to curative transplantation. These results also strengthen the biological rationale for integrating menin inhibitors earlier in the treatment course. Ongoing frontline trials including the global Phase III KOMET-017 study will clarify the role of Ziftomenib-based combinations in newly diagnosed fit and unfit patients with NPM1-mutated or KMT2A-rearranged AML.
Conclusion
Ziftomenib, a first-in-class oral menin inhibitor, demonstrated clinically meaningful activity and durable responses in heavily pretreated relapsed/refractory NPM1-mutated AML, meeting its registrational Phase II endpoint. With a manageable safety profile including low myelosuppression, minimal QTc effects, and predictable differentiation syndrome, Ziftomenib represents an important new targeted therapy for a genetically defined AML subset.
The KOMET-001 results mark a significant step forward in addressing an area of profound unmet need, and they lay the foundation for expanding menin inhibition into earlier lines of therapy with the goal of transforming long-term outcomes for patients with NPM1-mutated AML.
Ziftomenib in Relapsed or Refractory NPM1-Mutated AML. Wang ES, Montesinos P, Foran J, et al. J Clin Oncol. 2025;43:3381-3390
