Comparison of Gilteritinib and Salvage Chemotherapy in FLT3-Mutated Acute Myeloid Leukemia on the Number Needed to Treat for Various Clinical Outcomes: A Secondary Analysis of the Admiral Trial
FMS-like receptor tyrosine kinase-3 (FLT3) mutations are common in acute myeloid leukemia (AML) and are associated with poor prognosis. Historically, patients with relapsed/refractory (R/R) FLT3 mutation–positive (FLT3mut+) AML experienced dismal survival outcomes. Gilteritinib, a highly potent and selective FLT3 inhibitor, was recently approved as the first targeted therapy for patients with R/R FLT3mut+ AML, and has the potential to bring significant clinical benefits to these patients. The randomized, phase 3 ADMIRAL trial (NCT02421939; Perl, et al. 2019) was the first head-to-head study that evaluated 120-mg/day gilteritinib versus salvage chemotherapy in R/R FLT3mut+ AML patients. The ADMIRAL trial demonstrated that gilteritinib was superior to salvage chemotherapy based on significantly longer median overall survival (OS) and higher response rates, including complete remission/complete remission with partial hematological recovery (CR/CRh), composite CR (CRc), and hematopoietic stem cell transplantation (HSCT) rate. Based on these results, the current study estimated the number needed to treat (NNT) with gilteritinib, compared with salvage chemotherapy, in order to evaluate its clinical benefit with CR/CRh, CRc, 1-year OS, and HSCT rates.