FLT3 inhibitor improves survival in patients with FLT3+ acute myeloid leukaemia

Patients diagnosed with acute myeloid leukaemia with an FLT3 mutation (FLT3+ AML) may benefit from the addition of an FLT3 inhibitor to intensive chemotherapy postinduction by improving event-free (EFS) or overall survival (OS), suggests a study.

The authors, led by Brian G Bazzell of the Department of Pharmacy Services and Clinical Pharmacy, Michigan Medicine, MI, US, performed a single-centre, propensity-score matched, retrospective cohort study to assess the efficacy and safety of FLT3 inhibitors in the treatment of FLT3+ AML.

Median EFS was the primary outcome, while secondary ones were median OS, overall response rate (ORR), 30-day mortality, duration of neutropenia, duration of thrombocytopenia, consolidation cycle delays, documented infections, and all-cause hospital readmission.

Of the 83 FLT3+ AML patients treated with intensive induction therapy, 48 were propensity-score matched and analysed. Baseline characteristics were comparable between patients who received an FLT3 inhibitor after induction therapy and those in the historical control arm.

No significant difference was noted in median EFS between the FLT3 inhibitor arm and historical controls (not reached vs 8 months; p=0.343); the respective 18-month EFS for the two cohorts were 54 percent and 43 percent. Likewise, median OS (not reached vs 28.7 months; p=0.752), ORR (79.2 percent vs 79.2 percent), or safety outcome did not differ significantly between groups.

“Compared to historical controls, addition of an FLT3 inhibitor to intensive chemotherapy postinduction may improve EFS or OS in a real-world patient cohort with longer follow-up and a larger sample size,” the authors said.

“The omission of midostaurin in induction allowed for the use of an azole antifungal and the intensification of anthracycline dose may have contributed to high remission rates in both groups,” they added.