A phase II/III, multicenter, open-label, 3-arm study of gilteritinib, gilteritinib plus azacitidine, or azacitidine alone in the treatment of newly diagnosed FLT3 mutation-positive acute myeloid leukemia (AML) patients ineligible for intensive induction chemotherapy.

Abstract

TPS7068 Background: Gilteritinib, a highly selective, potent FLT3/AXL inhibitor, showed antileukemic activity with favorable tolerability in a Phase 1/2 trial of FLT3 mutation-positive (FLT3mut+) relapsed/refractory AML. In FLT3mut+ AML cell lines, gilteritinib plus azacitidine (AZA) inhibited growth, and induced apoptosis and differentiation. This ongoing Phase 2/3 trial will examine the efficacy, safety, and tolerability of gilteritinib alone, gilteritinib plus AZA or AZA alone in newly diagnosed FLT3mut+AML patients ineligible for intensive induction chemotherapy. Methods: This open-label, 3-arm, 2-stage randomized trial (NCT02752035) will enroll ~540 newly diagnosed adults with FLT3mut+ (FLT3-ITD or -TKD) AML; those with APL, BCR-ABL+, or active CNS leukemia will be excluded. Before initiation, the safety and tolerability of gilteritinib plus AZA will be assessed in a Safety Cohort to establish the appropriate gilteritinib dose for combination therapy. Subjects will then be randomized 1:1:1 to receive oral gilteritinib alone (120 mg daily; Days 1–28), AZA alone (75 mg/m2 by subcutaneous injection or intravenous infusion on Days 1–7), or AZA (75 mg/m2; Days 1–7) plus oral gilteritinib (daily on Days 1–28 at the dose determined from the Safety Cohort), and stratified by age ( < 75 vs ≥75 years). Subjects will continue treatment until a discontinuation event occurs. The primary endpoint is overall survival of subjects receiving gilteritinib or gilteritinib plus AZA versus AZA alone; the key secondary endpoint is event-free survival. Additional secondary endpoints: complete remission rate, leukemia-free survival, remission duration, composite remission rate, tolerability, and fatigue. Dose changes and interruptions are allowed in all treatment arms. A formal interim futility analysis by an Independent Data Monitoring Committee is planned when ~50 subjects in each treatment arm have either discontinued therapy or completed 2 treatment cycles. Enrollment began on November 21, 2016; as of January 31, 2017, the Safety Cohort is ongoing. Clinical trial information: NCT02752035.