NEW YORK – Invivoscribe said Monday that it has filed a supplemental premarket approval submission with the US Food and Drug Administration's Center for Devices and Radiological Health for the use of its LeukoStrat CDx FLT3 Mutation Assay as a companion diagnostic for Daiichi Sankyo's quizartinib in certain acute myeloid leukemia patients.
Specifically, the test will be used to identify newly diagnosed AML patients with the FLT3-ITD duplication mutation, coinciding with a decision by the FDA to grant priority review to the drug in combination with standard chemotherapy in that setting.
The assay was previously approved by the Japan Pharmaceuticals and Medical Devices Agency as a companion diagnostic to select patients with relapsed and refractory AML eligible for quizartinib.
The FLT3-ITD mutation occurs in approximately 25 percent of all newly diagnosed AML patients. It is estimated that more than 20,000 new cases of AML will be diagnosed in the US in 2022. The LeukoStrat CDx FLT3 assay is an in vitro PCR test which detects both FLT3-ITD mutations and FLT3 tyrosine kinase domain mutations from peripheral blood or bone marrow samples. The test is available as a kit currently distributed in Japan, the US, Europe, and China, and as a service in Japan, Germany, and the US through the San Diego-based company's LabPMM subsidiaries.
The FDA's decision to accept Daiichi Sankyo's NDA and to grant priority review is based on data from the Phase III QuANTUM-First trial presented at the European Hematology Association 2022 Congress. The trial showed that quizartinib combined with standard cytarabine and anthracycline induction and standard cytarabine consolidation chemotherapy, then continued as monotherapy gave a statistically significant advantage in overall survival to patients with newly diagnosed FLT3-ITD-positive AML compared to chemotherapy alone.
In a statement, Invivoscribe CSO and CEO Jeffrey Miller said that the filing "Is an important milestone. This submission to the FDA further solidifies the LeukoStrat CDx FLT3 Mutation Assay as the international benchmark for FLT3 mutation assessments."