NEW YORK – Daiichi Sankyo said Tuesday that it has initiated global regulatory filings for its FLT3 inhibitor Vanflyta (quizartinib) as a treatment for patients with FLT3-internal tandem duplication (ITD) mutation-positive acute myeloid leukemia.
The company will submit data from the Phase III QuANTUM-First trial, which researchers presented at the European Hematology Association Congress last week.
In QuANTUM-First, patients either received Vanflyta with standard induction and consolidation chemotherapy, followed by Vanflyta monotherapy, or they received just standard chemo. After 39.2 months of follow-up, patients in the Vanflyta arm had a median overall survival of 31.9 months compared to 15.1 months for those in the chemo arm. This translated to a 22.4 percent reduction in risk of death for those on Vanflyta compared to the chemotherapy group.
The adverse events with Vanflyta were mostly manageable, and no new safety signals were found in this study. Rates of events with fatal outcomes were 11.3 percent for Vanflyta and 9.7 percent for chemotherapy alone. A prolonged QT interval occurred in 2.3 percent of patients on Vanflyta, leading to discontinuation in 0.8 percent of patients. Two patients suffered cardiac arrest after developing severe hypokalemia.
The estimated five-year survival rate for AML is about 30.5 percent. About 25 percent of people with newly diagnosed AML have the FLT3-ITD mutation, which has been linked to poor prognosis, increased risk of relapse, and shorter overall survival.
Vanflyta was approved in Japan in 2019 for adults with relapsed or refractory, FLT3-ITD-positive AML along with the LeukoStrat assay as a companion diagnostic to identify eligible patients. That approval was based on earlier QuANTUM data showing median overall survival of 6.2 months in the Vanflyta group and 4.7 months in the chemotherapy-only group.
Outside of Japan, Vanflyta is an investigational agent. The US Food and Drug Administration has granted fast track designation to the drug as a treatment for newly diagnosed FLT3-ITD-positive AML in combination with standard cytarabine and anthracycline induction and cytarabine consolidation.