Gilteritinib versus chemotherapy in Japanese patients with FLT3 -mutated relapsed/refractory acute myeloid leukemia

Background Until recently, no effective targeted therapies for FLT3 -mutated ( FLT3 mut+) relapsed/refractory (R/R) acute myeloid leukemia (AML) were available in Japan. The FLT3 inhibitor, gilteritinib, was approved in Japan for patients with FLT3 mut+ R/R AML based on the phase 3 ADMIRAL trial, which demonstrated the superiority of gilteritinib over salvage chemotherapy (SC) with respect to overall survival (OS; median OS, 9.3 vs 5.6 months, respectively; hazard ratio, 0.64 [95% confidence interval 0.49, 0.83]; P < 0.001). Methods We evaluated the Japanese subgroup ( n = 48) of the ADMIRAL trial, which included 33 patients randomized to 120-mg/day gilteritinib and 15 randomized to SC. Results Median OS was 14.3 months in the gilteritinib arm and 9.6 months in the SC arm. The complete remission/complete remission with partial hematologic recovery rate was higher in the gilteritinib arm (48.5%) than in the SC arm (13.3%). After adjustment for drug exposure, fewer adverse events (AEs) occurred in the gilteritinib arm than in the SC arm. Common grade ≥ 3 AEs related to gilteritinib were febrile neutropenia (36%), decreased platelet count (27%), and anemia (24%). Conclusion Findings in Japanese patients are consistent with those of the overall ADMIRAL study population.