THE U.S. FOOD AND DRUG ADMINISTRATION (FDA) accepted a new drug application and granted Priority Review to quizartinib, a FLT3 inhibitor, for the treatment of adult patients with relapsed or refractory FLT3-ITD–positive acute myeloid leukemia (AML). The FDA is expected to make a decision on approval by May 25, 2019.
The new drug application is based on results of the phase III Quantum-R study, which was the first randomized phase III study to show that a FLT3 inhibitor prolonged overall survival as an oral, single agent compared with chemotherapy in patients with relapsed or refractory FLT3- ITD–positive AML. The results of Quantum-R were presented during the Plenary Session at the 23rd Congress of the European Hematology Association, and new analyses were presented during an oral presentation at the 2018 American Society of Hematology (ASH) Annual Meeting & Exposition.1-3
Quantum-R is a pivotal, global, phase III, open-label randomized study that enrolled 367 patients with FLT3-ITD–positive AML who were refractory to or in relapse with a duration of remission of up to 6 months after standard first-line AML therapy with or without hematopoietic stem cell transplantation. Patients were randomly assigned 2:1 to receive either single-agent oral quizartinib or salvage chemotherapy. The primary objective of the study was to determine whether single-agent quizartinib prolonged overall survival compared with salvage chemotherapy. The study met its primary endpoint of improving overall survival. ■
1. Cortes J, Khaled S, Martinelli G, et al: Quizartinib significantly prolongs overall survival in patients with FLT3-internal tandem duplication–mutated relapsed/ refractory AML in the phase 3, randomized, controlled QUANTUM-R trial. 2018 Congress of the European Hematology Association. Abstract LB2600. Presented June 16, 2018.
2. Cortes J, Khaled S, Martinelli G, et al: Efficacy and safety of single-agent quizartinib, a potent and selective FLT3 inhibitor, in patients with FLT3-internal tandem duplication–mutated relapsed/refractory acute myeloid leukemia enrolled in the global, phase III, randomized controlled Quantum-R trial. 2018 ASH Annual Meeting & Exposition. Abstract 563. Presented December 3, 2018.
3. Hills RK, Burnett AK, Gale R, et al: Outcomes in relapsed/ refractory patients with FLT3-ITD mutated AML are poor when treated with non-targeted therapy with a potential role for stem cell transplantation: Results from the NCRI AML Trials. 2018 ASH Annual Meeting & Exposition. Abstract 1392. Presented December 1, 2018.