Additional findings from phase 1 showed there to be no grade 3 or higher treatment-emergent adverse effects (AEs) in the patients harboring NPM1 mutations at either dose level. Among patients with KMT2A-rearranged disease given ziftomenib at a dose of 200 mg (n = 13) 30.8% experienced differentiation syndrome (DS) vs 25.0% of those with KMT2A-rearranged disease given the agent at 600 mg (n = 16). At the 600 mg dose 12.5% of patients also had febrile neutropenia.
Among patients with NPM1-mutated disease treated at the 600-mg dose, 20% experienced DS. Five percent of DS cases in these patients were grade 3 or higher in severity. Additionally, DS was observed in 38.5% and 37.5% of those with KMT2A-rearranged disease treated at the 200-mg and 600-mg doses, respectively. Grade 3 or higher DS was seen in 30.8% and 25.0% of these cases, respectively.
Now in phase 2 of the study, investigators are assessing the primary end points of CR or complete response with hematologic recovery (CRh), as well as the secondary end points of clinical benefit, safety, and tolerability.2
Phase 2 of the study is a registration-directed trial evaluating patients aged 18 years and older with AML who have a documented NPM1 mutation, are ECOG performance status of 0 to 2, and a life expectancy of 2 months or more. Patients are required to have adequate liver and kidney function, and peripheral white blood cell counts ≤ 30,000/μL. Additionally, patients are allowed to have received hydroxyurea to control and maintain white blood cell count prior to enrollment.
While ziftomenib is being evaluated as a monotherapy in patients with NPM1-mutant AML, the company plans to start 2 more trials, KOMET-007 and KOMET-008, to evaluate ziftomenib in combination with current standards of care across multiple patient populations, including NPM1-mutant and KMT2A-rearranged AML.
The trial is actively recruiting patients and is expected to enroll a total of 85 patients across various sites in the United States and Europe. The estimated study completion date is September 30, 2025.
"Although an NPM1 mutation is generally associated with a more favorable prognosis and is considered favorable risk by ELN 2017 and ELN 2022 risk stratification, relapse is NOT uncommon, especially in patients with concomitant FLT3 ITD mutations. We observed complete remissions with single agent ziftomenib, even with concomitant FLT3 or IDH mutations. I believe single agent ziftomenib will provide an attractive option for older patients, not eligible for intensive therapy, with NPM1 mutated AML. We have observed durable mutations in some of our phase I patients treated with the single agent. The true benefit of this agent may not be seen until we complete combination studies with intensive chemotherapy, less intensive chemotherapy and other inhibitors. The study of these combinations will launch in the near future. Ultimately, I believe we will incorporate ziftomenib and other menin inhibitors in first line therapy for NPM1-mutated AML," Harry Erba, MD, PhD, leukemia program director at Duke Cancer Institute in North Carolina and chair of the SWOG Leukemia Committee, told Targeted OncologyTM.
REFERENCES:
Kura oncology announces first patients dosed in phase 2 registration-directed trial of ziftomenib in NPM1-mutant acute myeloid leukemia. News release. Kura Oncology. February 9, 2023. Accessed February 9, 2023. https://yhoo.it/3JVKaE9
First in human study of ziftomenib in relapsed or refractory acute myeloid leukemia. ClinicalTrials.gov. Updated February 9, 2023. Accessed February 9, 2023. https://www.clinicaltrials.gov/ct2/show/NCT04067336