FLT3-ITD measurable residual disease from the QuANTUM-First trial

Area of Science:

• Hematology
• Oncology
• Molecular Biology

Background:

• Newly diagnosed acute myeloid leukemia (AML) with FLT3-ITD mutations has a poor prognosis.
• FLT3 inhibitors represent a targeted therapy approach for this AML subtype.

Purpose of the Study:

• To analyze measurable residual disease (MRD) and molecular biomarker impact in the QuANTUM-First trial.
• To evaluate quizartinib's efficacy in achieving deep molecular remission in FLT3-ITD mutated AML.

Main Methods:

• Post-hoc analysis of the randomized QuANTUM-First trial data.
• Utilized an amplicon-based next-generation sequencing assay for FLT3-ITD MRD assessment.
• Correlated MRD levels, FLT3-ITD insertion length, and co-mutations with clinical outcomes.

Main Results:

• Quizartinib significantly deepened FLT3-ITD MRD-negative remissions compared to placebo.
• Lower MRD levels post-induction correlated with reduced relapse rates and improved survival.
• Longer FLT3-ITD insertion mutations were associated with worse outcomes, but quizartinib benefit was consistent.
• NPM1 co-mutation status did not affect quizartinib's ability to increase MRD-negative rates.

Conclusions:

• Quizartinib addition to chemotherapy improves survival in newly diagnosed FLT3-ITD mutated AML.
• Achieving deep MRD negativity is a critical factor for favorable outcomes in this patient group.
• The FLT3-ITD MRD assay is a sensitive tool for monitoring treatment response.