as detected by an FDA-approved test.
The FDA also expanded the approved indication for the LeukoStrat CDx FLT3 Mutation Assay to include use with gilteritinib. The LeukoStrat CDx FLT3 Mutation Assay, developed by Invivoscribe, is used to detect the FLT3 mutation in patients with AML.
Gilteritinib, developed by Astellas Pharma, has demonstrated inhibitory activity against FLT3 internal tandem duplication and FLT3 tyrosine kinase domain.
The FDA’s approval of gilteritinib was based on an interim analysis of the ADMIRAL trial, which enrolled adults with relapsed or refractory AML who had a FLT3 ITD, D835 or I836 mutation, according to the LeukoStrat CDx FLT3 Mutation Assay.
Patients received gilteritinib at 120 mg daily until they developed unacceptable toxicity or did not show a clinical benefit. Efficacy results are available for 138 patients, with a median follow-up of 4.6 months.
The complete response (CR) rate was 11.6% (16/138), the CR rate with partial hematologic recovery (CRh) was 9.4% (13/138), and the CR/CRh rate was 21% (29/138). The median duration of CR/CRh was 4.6 months.
There were 106 patients who were transfusion dependent at baseline, and 33 of these patients (31.1%) became transfusion independent during the post-baseline period.
Seventeen of the 32 patients (53.1%) who were transfusion independent at baseline remained transfusion independent.
Safety results are available for 292 patients. The median duration of exposure to gilteritinib in this group was 3 months.
The most common adverse events were myalgia/arthralgia, transaminase increase, fatigue/malaise, fever, noninfectious diarrhea, dyspnea, edema, rash, pneumonia, nausea, constipation, stomatitis, cough, headache, hypotension, dizziness, and vomiting.
A total of 8% of patients (n = 22) discontinued gilteritinib because of adverse events, the most common of which were pneumonia (2%), sepsis (2%), and dyspnea (1%).