Gilteritinib in FLT3-mutated acute myeloid leukemia: A real-world Italian experience

Background and Methods: This real-world study evaluated the clinical effectiveness of gilteritinib in 205 patients with relapsed or refractory (R/R) FLT3-mutated acute myeloid leukemia (AML) enrolled in the Italian expanded access since January 2018. Results: Of the 205 patients, 124 (60.5%) received gilteritinib as a bridging therapy to allogeneic stem cell transplantation (allo-SCT), achieving complete remission in 52.4% (n = 65). The median overall survival (OS) for the entire cohort was 11.0 months, with estimated OS rates of 46.8% at 1 year and 28.5% at 3 years. Sixty patients (48% of those bridged) underwent allo-SCT after a median of 3.7 months on gilteritinib, achieving posttransplant OS rates of 65.2% at 1 year and 56.1% at 3 years. The acquisition of FLT3 mutations at relapse and the presence of TP53 co-mutations were significantly associated with inferior outcomes. Among 46 patients (22.4%) who relapsed after allo-SCT, gilteritinib treatment yielded an overall response rate (ORR) of 54.3%, a median OS of 11.1 months, and 1- and 3-year OS rates of 49.5% and 15.5%, respectively. Additionally, 35 patients (17.1%) previously treated with nonintensive chemotherapy received gilteritinib until disease progression or intolerance, achieving an ORR of 11.4%, a median OS of 5.9 months, and a 1-year OS rate of 29.0%. Conclusions: These real-world data confirm that clinical outcomes achieved with gilteritinib in patients with R/R FLT3-mutated AML are consistent with those observed in pivotal clinical trials. Notably, approximately half of the transplant-eligible patients were successfully bridged to allo-SCT and demonstrated encouraging long-term survival.