Yes, Xospata Targets FLT3-Mutated AML
Xospata (gilteritinib) is FDA-approved specifically for adults with relapsed or refractory acute myeloid leukemia (AML) with FLT3 mutations, including both ITD and TKD subtypes.[1] The approval came in 2018 based on the phase 3 ADMIRAL trial, which showed improved overall survival compared to salvage chemotherapy in this patient group.[2]
How Does Xospata Work in FLT3-Mutated AML?
Gilteritinib is a potent, selective FLT3 inhibitor that blocks both internal tandem duplication (ITD) and tyrosine kinase domain (TKD) mutations, common in about 30% of AML cases. It also has activity against AXL kinase, potentially enhancing its effects on leukemia cells.[1][3] Patients typically take 120 mg orally once daily until disease progression or toxicity.
What Does the Clinical Data Show?
In the ADMIRAL trial (n=371), median overall survival was 9.3 months with gilteritinib versus 5.6 months with chemotherapy (HR 0.64; p=0.0004). Complete remission or complete remission with partial hematologic recovery occurred in 21% of gilteritinib patients versus 11% on chemo.[2] Real-world studies confirm these benefits in heavily pretreated patients.[4]
When Is Xospata Used in Treatment Sequences?
It's indicated after at least one prior therapy for relapsed/refractory FLT3-mutated AML. Guidelines from NCCN and ELN recommend FLT3 testing at diagnosis and gilteritinib as a frontline option in relapse. It's not approved for newly diagnosed AML but can combine with chemo or venetoclax in trials.[3][5]
Common Side Effects and Patient Concerns
Differentiation syndrome (18%), febrile neutropenia (48%), and transaminase elevations occur frequently. QT prolongation requires monitoring. Myelosuppression is common but often manageable with dose adjustments.[1] Patients report fatigue and nausea as key issues in post-marketing data.
How Does It Compare to Other FLT3 Inhibitors?
| Drug | Key Differences | Survival Data (Relapsed/Refractory) |
|------|-----------------|-------------------------------------|
| Xospata (gilteritinib) | Oral, dual FLT3/AXL inhibitor; broadest mutation coverage | OS 9.3 mo[2] |
| Midostaurin (Rydapt) | IV/oral; frontline with chemo (not monotherapy in relapse) | RATIFY trial: frontline OS benefit[6] |
| Quizartinib (Vanflyta) | Oral, ITD-specific; approved 2023 for frontline + chemo | QuANTUM-First: EFS 31.9 mo vs 15.0 mo[7] |
Gilteritinib stands out for salvage settings; quizartinib excels upfront with lower cardiac risks.[5]
Patent Status and Availability
Xospata's key composition-of-matter patent (US 7,582,725) expires in 2024 in the US, with potential pediatric extensions to 2025. Method-of-use patents extend protection to 2032. No biosimilars are approved yet; generic entry likely post-2032 barring challenges.[8]
Sources
[1]: Xospata Prescribing Information (FDA)
[2]: NEJM: ADMIRAL Trial (2019)
[3]: NCCN AML Guidelines v2.2024
[4]: Blood Advances: Real-World Gilteritinib (2022)
[5]: ELN 2022 AML Recommendations
[6]: NEJM: RATIFY Trial (2017)
[7]: NEJM: QuANTUM-First (2023)
[8]: DrugPatentWatch: Gilteritinib Patents