Kura Oncology Presents Updated Clinical Data from KOMET-001 Trial of Menin Inhibitor Ziftomenib at ASH Annual Meeting

SAN DIEGO, Dec. 10, 2022 - Kura Oncology, Inc. (Nasdaq: KURA), a clinical-stage biopharmaceutical company committed to realizing the promise of precision medicines for the treatment of cancer, today announced updated clinical data from KOMET-001, a Phase 1/2 trial of the Company’s potent and selective menin inhibitor, ziftomenib, including an encouraging safety and tolerability profile and clinical activity in patients with relapsed/refractory acute myeloid leukemia (AML).

• 30% CR rate at 600 mg in 20 patients with relapsed/refractory NPM1-mutant AML
• Low frequency of differentiation syndrome, including 5% rate (1/20) of ≥ Grade 3 among NPM1-mutant patients treated at 600 mg
• 600 mg determined as recommended Phase 2 dose for ziftomenib in NPM1-mutant AML following positive Type C meeting with FDA
• Company expects to dose first patient in Phase 2 registration-directed trial in NPM1-mutant AML in first quarter of 2023
• Further clinical development of KTM2A-rearranged AML to be pursued in combination with standards of care
• Multiple combination studies of ziftomenib in NPM1-mutant and KMT2A-rearranged AML anticipated in 2023

In order to inform an optimal Phase 2 dose and in consultation with the U.S. Food and Drug Administration (FDA) and its Project Optimus initiative, Kura conducted a Phase 1b trial with two randomized expansion cohorts, each comprised of NPM1-mutant and KMT2A-rearranged AML patients. A total of 53 patients were ultimately treated in the Phase 1b trial: 17 at 200 mg and 36 at 600 mg. These patients were heavily pretreated and received a median of three prior lines of therapy (range 1-11), with the majority of patients having received prior venetoclax and a quarter having progressed after at least one prior stem cell transplant. As of the data cutoff on October 24, 2022, 10 of the patients treated at 600 mg remained on ziftomenib and 17 were still in follow-up. Median duration of response has not been reached.

Ziftomenib demonstrated optimal clinical benefit at 600 mg with a 30% CR rate (6/20) in patients with NPM1-mutant AML, compared to 17% (1/6) at 200 mg. Notably, four of the six NPM1-mutant patients who achieved a CR at 600 mg had IDH and/or FLT3 co-mutations. Overall, four of the seven patients with IDH co-mutations achieved a CR on ziftomenib. Of the five patients assessed for MRD at 600 mg, three were MRD negative.

Kura also announced that 600 mg has been determined as the recommended Phase 2 dose for ziftomenib in NPM1-mutant AML following a positive Type C meeting with the FDA. Agreement was also reached on key elements of a registration-enabling study design, and the Company is now preparing to initiate the Phase 2 registration-directed trial. Kura expects to dose the first patient in the first quarter of 2023, followed by a series of combination studies in frontline and relapsed/refractory AML that will prioritize development with venetoclax and FLT3 in combination.

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