Quizartinib Prolongs Overall Survival in Deadly Form of AML Compared With Chemotherapy

An investigational drug has prolonged survival for patients with acute myeloid leukemia (AML) who have a genetic mutation called FMS-like internal tandem duplications (FLT3-ITD). The results of the phase 3 trial, which was led by The University of Texas MD Anderson Cancer Center, were presented at the European Hematology Society’s 23rd Congress.¹

AML with the FLT3-ITD mutation is a rare and deadly form of the disease that affects approximately one-third of patients with AML. These patients present with more aggressive disease and are more likely to relapse after remission.²

So far, quizartinib, a second-generation FLT3 inhibitor, has shown promising activity. The new findings of the QUANTUM-R study presented at the European Hematology Society have confirmed the efficacy and safety of the treatment, as well as the value of targeting FLT3-ITD with the agent, which is a small molecule receptor tyrosine kinase inhibitor.

“Currently, there are no approved targeted therapies for patients with relapsed FLT3-ITD-associated AML, which represent a significant unmet medical need,” Jorge Cortes, MD, deputy chair and professor of Leukemia at MD Anderson, as well as the lead investigator of the QUANTUM-R study, said in a statement. “Our findings demonstrated that patients on quizartinib alone had an estimated overall survival of 27% after 52 weeks of treatment compared to 20% for patients on standard chemotherapies.”

The study enrolled adult patients who either had refractory AML or who had relapsed 6 months or less following complete remission. A total of 367 patients were randomized 2:1 to receive either quizartinib once daily or the investigator’s choice of several chemotherapy options (low-dose cytarabine; the combination of mitoxantrone, etoposide, and cytarabine; or the combination of fludarabine, cytarabine, and idarubicin).

The median overall survival was 27 weeks for patients treated with quizartinib and 20.4 weeks for patients treated with chemotherapy. Treatment-emergent adverse events were comparable between the 2 arms.

“These pivotal data confirm that targeting FLT3-IT with this potent new therapy may be of significant clinical value,” said Cortes. “These results represent the first positive phase 3 trial to demonstrate improved overall survival in patients with AML-associated FLT3-ITD.”

References

1. Cortes J, Khaled S, Martinelli G, et al. Quizartinib significantly prolongs overall survival in patients with FLT3-internal tandem duplication—mutated (MUT) relapsed/refractor AML in the phase 3, randomized, controlled QUANTUM-R trial. Presented at the 23rd Congress of the European Hematology Association. June 16, 2018; Stockholm, Sweden.

2. Fathi AT, Chen YB. Treatment of FLT3-ITD acute myeloid leukemia. Am J Blood Res. 2011;1(2):175-189. PMID: 22432079.