The US Food and Drug Administration (FDA) has granted orphan drug designation to gilteritinib for the treatment of patients with acute myeloid leukemia (AML).
Gilteritinib, an inhibitor of FLT3 and AXL, has demonstrated activity against FLT3 internal tandem duplication (ITD) as well as tyrosine kinase domain, 2 mutations that are seen in up to a third of patients with AML.
Astellas Pharma Inc. is currently investigating gilteritinib in phase 3 trials of AML patients.
Results from a phase 1/2 study of gilteritinib in AML were presented at the 2017 ASCO Annual Meeting.
The goal of the study was to determine the tolerability and antileukemic activity of once-daily gilteritinib in a FLT3-ITD-enriched, relapsed/refractory AML population.
The drug exhibited “potent” FLT3 inhibition at doses greater than 80 mg/day. In patients who received such doses, the greatest overall response rate was 52%, and the longest median overall survival was 31 weeks.
The maximum tolerated dose of gilteritinib was 300 mg/day. Dose-limiting toxicities included diarrhea and liver function abnormalities.
About orphan designation
The FDA grants orphan designation to products intended to treat, diagnose, or prevent diseases/disorders that affect fewer than 200,000 people in the US.
The designation provides incentives for sponsors to develop products for rare diseases. This may include tax credits toward the cost of clinical trials, prescription drug user fee waivers, and 7 years of market exclusivity if the product is approved.