Gilteritinib Prolongs Survival in Patients with FLT3-Mutated AML

New data from a phase 3 clinical trial showed that treatment with gilteritinib (Xospata, Astellas Pharma) improved survival for patients with relapsed or refractory acute myeloid leukemia (AML) with a FMS-like tyrosine kinase 3 (FLT3) mutation.

The results, which were presented at the AACR Annual Meeting, were based on the phase 3 ADMIRAL study and build on previous data.

In November 2018, the FDA approved gilteritinib for the treatment of adult patients with relapsed or refractory AML with a FLT3 mutation. The approval was based on safety data and an interim analysis of response to gilteritinib from the phase 3 trial. After a median follow-up of 4.6 months, 29 of the 138 patients in the study had achieved complete remission (CR) or CR with partial hematologic recovery, according to the study.

Now, the final analysis of the results from the ADMIRAL study demonstrate gilteritinib’s efficacy relative to standard chemotherapy, which included the investigator’s choice of low-dose cytarabine; azacitidine; mitoxantrone, etoposide, and cytarabine; and fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin.

For the efficacy data, 247 of the 371 patients enrolled were randomly assigned to gilteritinib and 124 to standard chemotherapy. At the final analysis, patients who were treated with gilteritinib demonstrated a 36% reduction in risk of death compared with those assigned standard chemotherapy. According to the data, median overall survival was 9.3 months for the gilteritinib group versus 5.6 months for the standard chemotherapy group. At 1 year, 37.1% of the patients treated with gilteritinib were alive compared with 16.7% of those assigned standard chemotherapy.

Additionally, the combined rate of complete remission and complete remission with partial hematologic recovery was 34% for those treated with gilteritinib and 15.3% for those treated wth standard chemotherapy.

“These survival data combined with gilteritinib's relatively low toxicity establish gilteritinib monotherapy as the new standard of care for patients with relapsed or refractory FLT3-mutated AML,” Alexander E. Perl, MD, associate professor in the Division of Hematology/Oncology at the Perelman School of Medicine at the University of Pennsylvania, and a member of the Abramson Cancer Center, said in a press release. “In addition, the relatively low toxicity of gilteritinib and the fact that it is an oral therapy means physicians can manage patients in the outpatient setting, which is a paradigm shift for the treatment of this disease.”

According to Dr Perl, the longest survival in the gilteritinib treatment arm was seen among patients who proceeded to transplant and then resumed gilteritinib thereafter to prevent relapse. However, he noted that long-term survival was uncommon in both treatment arms, indicating a need to further test gilteritinib in combination with other therapies.

Reference

Gilteritinib Improved Survival for Patients With Acute Myeloid Leukemia [news release]. American Association for Cancer Research. https://www.aacr.org/Newsroom/Pages/News-Release-Detail.aspx?ItemID=1295. Accessed April 1, 2019.