AML cells
The US Food and Drug Administration (FDA) has granted fast track designation to gilteritinib for the treatment of adults with FLT3 mutation-positive relapsed or refractory acute myeloid leukemia (AML).
Gilteritinib is a compound that has demonstrated inhibitory activity against FLT3 internal tandem duplication (ITD) and FLT3 tyrosine kinase domain, 2 mutations that are seen in approximately one-third of patients with AML.
Gilteritinib has also demonstrated inhibition of AXL, which is reported to be associated with therapeutic resistance.
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.
Researchers said 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 fast track designation
The FDA’s fast track program is designed to facilitate the development and expedite the review of products intended to treat or prevent serious or life-threatening conditions and address unmet medical need.
Through the fast track program, a product may be eligible for priority review. In addition, the company developing the product may be allowed to submit sections of the new drug application or biologics license application on a rolling basis as data become available.
Fast track designation also provides the company with opportunities for more frequent meetings and written communications with the FDA.
About orphan designation
Gilteritinib also has orphan drug designation for the treatment of AML.
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.
