Dr. Koprivnikar Discusses FLT3 Inhibitors in Hematologic Malignancies

Jamie Koprivnikar, MD, medical oncologist, John Theurer Cancer Center, discusses FLT3 inhibitors in the treatment of hematologic malignancies.

FLT3 inhibitors are often associated with acute myeloid leukemia (AML), but they are being looked at in other hematologic malignancies as well. A phase II trial looked at untreated patients over the age of 60 who had FLT3-mutated ITD-positive myelodysplastic syndrome (MDS), chronic myeloid leukemia (CML), or AML. This trial looked at quizartinib in combination with either azacitidine (Vidaza) or low-dose cytarabine. Promising responses were observed in patients who were previously untreated, with 11 out of 12 patients responding. Overall survival in this population was 18.6 months.

Interestingly, in the previously treated cohort, 5 patients had seen prior exposure to FLT3 inhibitors. This did not affect response, Koprivnikar explained, as 4 out of 5 (80%) of these patients still responded to the combination with quizartinib. An overall response rate of 68% was observed in this previously-treated population, with a median overall survival of 11.2 months.

Finding the optimal FLT3 inhibitor for each particular subgroup will be a continuing area of investigation, says Koprivnikar, as these agents are showing improvements in outcome.