The European Commission has approved Astellas’ oral once-daily therapy Xospata (gilteritinib) as a monotherapy for the treatment of adult patients with relapsed or refractory (resistant to treatment) acute myeloid leukemia with a FLT3 mutation. Gilteritinib has the potential to improve treatment outcomes for AML patients with two forms of the most common mutation—FLT3 internal tandem duplication and FLT3 tyrosine kinase domain mutation.
This approval is based on results from the phase III ADMIRAL trial, which investigated gilteritinib versus salvage chemotherapy in patients with relapsed or refractory FLT3mut+ AML. Patients treated with gilteritinib had significantly longer overall survival than those who received salvage chemotherapy.
Median OS for patients who received gilteritinib was 9.3 months, compared to 5.6 months for patients who received salvage chemotherapy (Hazard Ratio = 0.64 [95% CI 0.49, 0.83], P=0.0004). Rates of one-year survival were 37% for patients who received gilteritinib, compared to 17% for patients who received salvage chemotherapy.
The EC marketing authorization for gilteritinib in relapsed or refractory FLT3mut+ AML is applicable to the European Union member countries, and is also valid in Iceland, Norway and Liechtenstein. Gilteritinib was designated an orphan medicinal product and also received accelerated assessment from the European Medicines Agency earlier this year, which reduced the timeframe for approval.
Patients’ FLT3mut+ status can change over the course of AML treatment, even after relapse. Due to the poor outcomes associated with FLT3mut+ AML, patients’ FLT3 mutation status may be confirmed to help inform the best treatment approach.
