The European Commission has approved Astellas Pharma's Xospata (gilteritinib) for patients with relapsed or refractory FLT3-positive acute myeloid leukemia (AML), marking a significant advancement in targeted therapy for this aggressive blood cancer. The approval follows an accelerated review process and builds upon the drug's existing approvals in the United States and Japan.
Clinical data from the pivotal ADMIRAL trial demonstrated compelling efficacy, with Xospata achieving a median overall survival of 9.3 months compared to 5.6 months for salvage chemotherapy, the current standard second-line treatment. This survival benefit represents a crucial advancement for patients with limited therapeutic options.
Disease Impact and Treatment Significance
FLT3 mutations affect approximately 30% of AML patients and are associated with particularly aggressive disease characteristics, including higher relapse rates and faster progression. "AML is a rare cancer and patients with a FLT3 mutation have a particularly poor prognosis, with a median survival of less than six months following treatment with salvage chemotherapy," explained Giovanni Martinelli, an ADMIRAL trial investigator.
Therapeutic Advantages and Market Position
Xospata distinguishes itself through its dual-mutation targeting capability, effectively inhibiting both ITD and TKD FLT3 mutations. This broader coverage provides an advantage over competing treatments such as Daiichi Sankyo's quizartinib, which only targets the ITD mutation, albeit with greater potency against that specific variant.
The approval positions Xospata favorably in a market that includes Novartis's first-generation FLT3 inhibitor Rydapt (midostaurin), approved in 2017 for first-line treatment in combination with chemotherapy. While initially focused on second-line treatment, Astellas has indicated plans to expand Xospata's use into the first-line setting.
Commercial Performance and Market Outlook
Early commercial indicators show promise, with Astellas reporting approximately $22 million in Xospata sales during the first quarter of fiscal 2019. The company projects full-year sales to reach around $140 million, reflecting growing confidence in the drug's market potential.
The competitive landscape continues to evolve, with additional FLT3 inhibitors in development, including AROG Pharma's crenolanib, which is currently undergoing late-stage trials for both newly-diagnosed and relapsed/refractory AML. This ongoing innovation underscores the significant unmet need and market opportunity in FLT3-positive AML treatment.
