On June 11, 2023, Kura Oncology, Inc. (the “Company”) announced updated clinical data from KOMET-001, a Phase 1/2 clinical trial of the Company’s potent and selective menin inhibitor, ziftomenib, that were presented during a late-breaking oral session at the 2023 European Hematology Association Annual Congress in Frankfurt, Germany.
As of the data cutoff on April 12, 2023, seven of the 20 patients (35%) with nucleophosmin 1- (“NPM1-”) mutant acute myeloid leukemia (“AML”) treated at the recommended Phase 2 dose (“RP2D”) of 600 mg achieved a complete remission (“CR”) with full count recovery. Notably, 33% (2/6) of patients with FLT3 co-mutations and 50% (4/8) of patients with IDH co-mutations achieved a CR on ziftomenib. Two patients underwent a stem cell transplant (“SCT”) and remain in remission as of the data cutoff, including one on post-SCT ziftomenib maintenance therapy. An eighth patient who had a CR with incomplete recovery (“CRi”) at the time of transplant subsequently evolved to a CR and remains on study.
The median duration of response for all NPM1-mutant patients was 8.2 months (95% CI: 1.0 to NE), with a median follow-up of 8.8 months. The median duration of response for patients censored at SCT was 5.6 months (95% CI: 1.0 to NE). As of the cutoff date, three patients treated at 600 mg remain on study and in CR; an additional NPM1-mutant patient treated at 200 mg remained on ziftomenib for 36 cycles.
As part of an ongoing analysis, the resistance mutation MEN1-M3271 has been detected in three patients treated with ziftomenib: in two patients, the mutation was detected at study entry after the patients had progressed on a prior menin inhibitor, and in the third patient, the mutation was detected after four cycles of ziftomenib therapy and, despite the mutation, the patient was maintained in a condition of stable disease through cycle 7. These data show that MEN1 mutations developed in just 3% (1/29) of patients analyzed following treatment with ziftomenib and suggest that resistance mutations are less likely to evolve after prolonged exposure to ziftomenib monotherapy. A key new biochemical finding, confirmed by crystal structure, demonstrates that ziftomenib retains full activity against the MEN1-T349M mutation, detected in two-thirds of patients who acquired menin resistance mutations on another recent menin inhibitor trial.
Continuous daily dosing of ziftomenib was well tolerated and the safety profile remains consistent with features of underlying disease. The on-target effect of differentiation syndrome was manageable, with 15% of patients experiencing Grade 1 or 2 events and 5% experiencing a Grade 3 event.
Enrollment in a Phase 2 registration-directed study of ziftomenib in patients with relapsed/refractory NPM1-mutant AML continues to outperform projections. The study is expected to enroll a total of 85 patients at 62 U.S. and European sites. The Company is also preparing to initiate a series of studies to evaluate ziftomenib in combination with current standards of care in earlier lines of therapy and across multiple patient populations, including NPM1-mutant and KMT2A-rearranged AML. The Company has begun site activation in the first of these studies, KOMET-007, and is on track to dose the first patients this quarter.
On June 12, 2023, the Company will host a virtual investor event and present certain materials related to the Company (the “Presentation”). A copy of the Presentation is attached hereto as Exhibit 99.1 and incorporated herein by reference.
Forward-Looking Statements
Statements contained in this Current Report on Form 8-K regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements, including, but not limited to, statements regarding, among other things, the efficacy, safety and therapeutic potential of ziftomenib, potential benefits of combining ziftomenib with appropriate standards of care, progress and expected timing of the ziftomenib program, and plans regarding future clinical trials.
