TOKYO and ROCKVILLE, Md., March 9, 2023 – Astellas Pharma Inc. (TSE: 4503, President and CEO: Kenji Yasukawa, Ph.D., “Astellas”) and the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) today announced topline results from the Phase 3 MORPHO clinical trial evaluating gilteritinib as a maintenance therapy following allogeneic hematopoietic stem cell transplantation (HSCT) for patients with FMS-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) mutated acute myeloid leukemia (AML). Based on the data, the study did not meet its pre-defined primary endpoint of relapse-free survival (RFS) for patients treated with gilteritinib compared to placebo. The study was conducted in collaboration with BMT CTN.

The Phase 3 MORPHO trial is a randomized, double-blind, placebo-controlled, multi-center trial that compares gilteritinib to placebo as maintenance therapy over a period of two years following HSCT in 356 patients with FLT3-ITD mutated AML and in remission after induction therapy. The most frequent treatment-emergent adverse events (TEAEs) were decrease in neutrophil count, diarrhea and nausea, which were generally consistent with previous studies of gilteritinib. Detailed results will be submitted for publication and for consideration at upcoming medical meetings. Since RFS was not statistically significant at the primary analysis, the study, including follow-up, will be stopped as per the study protocol.

“While we are disappointed by these results, we remain committed to providing AML patients with treatment options throughout the disease continuum,” said Ahsan Arozullah, M.D., M.P.H., Senior Vice President and Head of Development Therapeutic Areas, Astellas. “We will be conducting a thorough review of the full data set and plan to share detailed results in the future.”

“Though the Phase 3 MORPHO clinical trial did not meet its primary endpoint, we are proud of the fact that we were able to garner international cooperation to address this important question in a rare disease," said Mary M. Horowitz, M.D., Principal Investigator of the BMT CTN Data and Coordination Center. "In collaboration with Astellas, we will continue the evaluation of the study results, which included multiple clinically meaningful secondary endpoints, and assess their impact on AML patient care.”

Gilteritinib is a FLT3 inhibitor with demonstrated activity against FLT3-ITD, a common driver mutation that presents with a high disease burden and poor prognosis, and FLT3-tyrosine kinase domain (TKD) mutations. Gilteritinib is available as XOSPATA® in the U.S., Japan, China and selected European countries for the treatment of adult patients who have relapsed or refractory FLT3+ AML.

This result will have no impact on the financial forecasts of the current fiscal year ending March 31, 2023.


Click below for a copy of the full press release


Contact the Media Relations team
Communications & Investor Relations
Main phone line for Media: +81-3244-3201 
Business hours (JST)
From Monday to Thursday: 8:45 am to 5:45 pm, Friday: 8:45 am to 4:00 pm
(closed on Saturdays, Sundays, national holidays and company holidays)