NORTHBROOK, Ill., Dec. 6, 2015 /PRNewswire/ -- Astellas US, LLC, a subsidiary of Tokyo-based Astellas Pharma Inc. (Tokyo: 4503), today announced that updated data from the Phase 1/2 CHRYSALIS trial evaluating the safety, tolerability and  antileukemic activity of gilteritinib (ASP2215), an orally-administered inhibitor of FLT3/AXL in patients with relapsed or refractory (R/R) acute myeloid leukemia (AML), were presented during an oral scientific session at the American Society of Hematology (ASH) 2015 annual meeting in Orlando.

Gilteritinib has demonstrated inhibitory activity against FLT3 internal tandem duplication (ITD) as well as tyrosine kinase domain (TKD), two common types of FLT3 mutations that are seen in up to one-third of patients with AML.

This updated analysis of the Phase 1/2 study included 169 patients with FLT3 mutations who were treated with  at least 80 mg gilteritinib. A 53% overall response rate (ORR) was demonstrated  regardless of prior therapy. Additionally, a 56% ORR was observed in patients who had a FLT3-ITD mutation, and 48% ORR was observed in patients who were treated with TKI prior to the study. Median overall survival was approximately 31 weeks (95% CI: 24–35). Treatment-related adverse events (AE) reported in >10% of the safety population included diarrhea (16%), fatigue (13%), AST increase (12%). Grade >3 QTc prolongation was reported in 3% of subjects.

"We are pleased to see that gilteritinib demonstrates antileukemic activity even in patients whose mutations have previously been associated with poor outcomes," said Trial Investigator  Jessica Altman, M.D. and associate professor of Hematology/Oncology at Northwestern University's Feinberg School of Medicine.

"We live in an era of personalized medicine and targeted therapies, yet there is still a significant need for more effective AML treatments, particularly for patients with well-characterized FLT3 molecular defects." said Erkut Bahceci, M.D. and executive medical director, Astellas. "Targeting both FLT3-ITD and FLT3-TKD mutations, as well as AXL, can potentially help avoid the acquired resistance seen with existing FLT3-ITD inhibitors and may  increase duration of therapy."

Recently, Astellas announced the dosing of the first patient in the ADMIRAL trial, a randomized Phase 3 registrational study of gilteritinib versus salvage chemotherapy in patients with R/R AML.The primary endpoint of the trial is overall survival. More information about this trial can be found at www.clinicaltrials.gov, trial identifier NCT02421939.

About Acute Myeloid Leukemia
Acute myeloid leukemia (AML) is a cancer that impacts the blood and bone marrow and is most commonly experienced in older adults. According to the American Cancer Society, in 2015, there will be an estimated 20,830 new cases of AML diagnosed in the United States, and about 10,460 cases will result in death.

About Astellas
Astellas is a pharmaceutical company dedicated to improving the health of people around the world through the provision of innovative and reliable pharmaceutical products. For more information on Astellas, please visit our website at www.astellas.us. You can also follow us on Twitter at @AstellasUS. Visit our Facebook page at www.facebook.com/AstellasUS.

Logo - http://photos.prnewswire.com/prnh/20140416/84970

SOURCE Astellas Pharma US, Inc.