Of 371 patients enrolled in the ADMIRAL trial, 247 were assigned to 120-mg/day gilteritinib and 75 (30.5%) relapsed during the study. Most relapses (n=72/75; 96.0%) occurred ≤4 weeks from the last gilteritinib dose….At relapse, 27/40 patients (67.5%) had new mutations, including mutations in Ras/MAPK pathway genes (n=18), FLT3 (n=6), WT1 (n=3), IDH1 (n=1), and GATA2 (n=1) (Table). Thirteen patients (32.5%) had no new mutations....In patients with FLT3mut+ R/R AML who relapsed on gilteritinib therapy, Ras/MAPK pathway gene mutations and FLT3 F691L gatekeeper mutations were the most common mutational events.