Investigational drug Shows Survival Benefit For Some Leukemia Patients in Phase 3 study

An investigational drug taken while undergoing chemotherapy demonstrated superior overall survival compared to chemotherapy alone in adult patients with a common, highly aggressive subtype of acute myeloid leukemia (AML).

The large international phase 3 study, co-led by Duke Cancer Institute researcher Harry P. Erba, M.D., Ph.D., demonstrated that the drug quizartinib plus chemotherapy resulted in a median overall survival of 31.9 months. The median survival time was more than twice that of study patients randomly assigned to standard chemotherapy and placebo (15.1 months).

The findings are presented at the European Hematology Association meeting in Vienna, Austria on June 11.

AML is one of the most common forms of leukemia in adults, representing about one-third of all cases. The five-year survival rate of AML is about 29%. Patients in the study had a subtype of AML known as FLT3-ITD positive, which typically has worse outcomes.

"We focused on patients with AML in this high-risk group and saw a significant survival benefit with the addition of a very potent and highly targeted therapy to the standard treatment," Erba said.

The study enrolled 539 AML patients with the FLT3-ITD mutation who were randomly assigned to either receive the study drug or placebo, along with chemotherapy. Patients were between the ages of 18 and 75 years old.

A second round of chemotherapy was allowed if AML was found in a post-induction bone marrow exam. Patients who achieved complete remission or complete remission with incomplete blood count recovery received up to four cycles of a standard chemotherapy regimen called high dose Ara-C with either quizartinib or a placebo followed by up to three years of continuation therapy with quizartinib or placebo alone. Patients in remission could also proceed with a bone marrow transplant.

The oral pill is manufactured by Daiichi Sankyo, which funded the study.

"We are encouraged by these findings, particularly for this group of AML patients who have particularly poor outcomes," Erba said. "The data indicates that this therapy was also generally well-tolerated, which is important."