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So Sekine(224)-205-5173
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Astellas Initiates Phase 3 Registration Trial of gilteritinib (ASP2215) in Relapsed or
Refractory Acute Myeloid Leukemia PatientsTOKYO – October 28, 2015 – Astellas Pharma Inc. (TSE: 4503) today announced dosing of
the first patient in a randomized Phase 3 registration trial of gilteritinib (ASP2215) versus
salvage chemotherapy in patients with relapsed or refractory (R/R) acute myeloid leukemia(AML). The primary endpoint of the trial is overall survival (OS).
Gilteritinib is a receptor tyrosine kinase inhibitor of FLT3 and AXL, which are involved in thegrowth of cancer cells. Gilteritinib has demonstrated inhibitory activity against FLT3 internal
tandem duplication (ITD) as well as tyrosine kinase domain (TKD), two common types of FLT3mutations that are seen in up to one third of patients with AML.
The gilteritinib Phase 3 trial follows a Phase 1/2 trial, which evaluated doses from 20 to 450 mg
once daily. A parallel multi-dose expansion cohort was initiated based on the efficacy seen inthe dose escalation phase. Preliminary data from the Phase 1/2 trial presented at the 2015
American Society of Clinical Oncology annual meeting demonstrated a 57.5 percent overall
response rate and a 47.2 percent composite Complete Response (CR) rate (CR + CR withincomplete platelet recovery + CR with incomplete hematologic recovery) in 106 patients with
FLT3 mutations who received 80 mg and higher doses. Median duration of response was 18weeks across all doses and median OS was approximately 27 weeks at 80 mg and above in
FLT3 mutation positive patients. Common drug-related adverse events (> 10%) observed in thestudy were diarrhea (13.4%), fatigue (12.4%) and AST increase (11.3%). At the 450 mg dose,
two patients reached dose-limiting toxicity (grade 3 diarrhea and ALT/AST elevation) and themaximum tolerated dose was determined to be 300 mg.
On October 27, 2015, the Japanese Ministry of Health, Labor and Welfare (MHLW) announced
the selection of gilteritinib as one of the first products designated for SAKIGAKE.

About the Phase 3 StudyThe Phase 3 trial is an open-label, multicenter, randomized study of gilteritinib versus salvage
chemotherapy in patients with Acute Myeloid Leukemia (AML). The study will enroll 369 patientswith FLT3 activating mutation in bone marrow or whole blood, as determined by central lab,
AML who are refractory to or have relapsed after first-line AML therapy. Subjects will berandomized in a 2:1 ratio to receive gilteritinib (120 mg) or salvage chemotherapy consisting ofLoDAC (low-dose cytarabine), azacitidine, MEC (mitoxantrone, etoposide, and intermediatedose cytarabine), or FLAG-IDA (fludarabine, cytarabine, and granulocyte colony-stimulating
factor with idarubicin). The primary endpoint of the trial is OS. For more information about thistrial go to www.clinicaltrials.gov, trial identifier NCT02421939.
Gilteritinib was discovered through a research collaboration with Kotobuki Pharmaceutical Co.,
Ltd., and Astellas has exclusive global rights to develop, manufacture and potentiallycommercialize gilteritinib.
About Acute Myeloid Leukemia
Acute myeloid leukemia is a cancer that impacts the blood and bone marrow and mostcommonly 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 SAKIGAKESAKIGAKE designation system can shorten the review period with the following 3 approaches:
1) Prioritized Consultation, 2) Substantial Pre-application Consultation and 3) Prioritized Review.
And also, the system will help promote the development with the following 2 approaches: 4)
Review Partner System (to be conducted by the Pharmaceuticals and Medical Devices Agency)
and 5) Substantial Post-Marketing Safety Measures.
About Astellas
Astellas Pharma Inc., based in Tokyo, Japan, is a company dedicated to improving the health ofpeople around the world through the provision of innovative and reliable pharmaceuticalproducts. We focus on Urology, Oncology, Immunology, Nephrology and Neuroscience asprioritized therapeutic areas while advancing new therapeutic areas and discovery researchleveraging new technologies/modalities. We are also creating new value by combining internal
capabilities and external expertise in the medical/healthcare business. Astellas is on theforefront of healthcare change to turn innovative science into value for patients. For more
information, please visit our website at www.astellas.com/en.
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