Tokyo, March 22, 2018 - Astellas Pharma Inc. (President and CEO: Yoshihiko Hatanaka, “Astellas” ) today announced that the Japanese Ministry of Health, Labour and Welfare (MHLW) has granted Orphan Drug Designation to gilteritinib for the treatment of FLT3mut+ Acute Myeloid Leukemia (AML), the drug’s prospective indication.

Orphan drug designation system in Japan aims to support the development of drugs for diseases that, despite there being a significant medical need for treatments, affect only a small number of patients, and for which research and development is virtually nonexistent. As stipulated in Article 77 of the Pharmaceuticals, Medical Devices, and Other Therapeutic Products Act of Japan, the designation is granted by the minister of Health, Labour and Welfare for drugs that meet the designation criteria which include the following: the number of patients who may use the drug is less than 50,000 in Japan; there is no alternative appropriate drug or treatment in Japan; high efficacy or safety is expected compared to existing products. Specific measures to support the development of orphan drugs include subsidies for research and development expenditures, prioritized consultation regarding clinical development, reduced consultation fees, tax incentives, priority review of applications, reduced application fees, and extended registration validity period1

AML is a cancer that impacts the blood and bone marrow, and its incidence increases with age. In Japan, approximately 5,500 patients are diagnosed with AML each year2. Gilteritinib is an investigational compound that has demonstrated inhibitory activity against FLT3 internal tandem duplication (ITD) as well as FLT3 tyrosine kinase domain (TKD), two common types of FLT3 mutations that are seen in approximately one-third of patients with AML. Further, gilteritinib has also demonstrated inhibition of the AXL receptor in AML cell lines.

Astellas will continue to develop gilteritinib to provide it to FLT3mut+ AML patients as early as possible.

(2): KantarHealth. TREATMENT ARCHITECTURE: JAPAN LEUKEMIA, ACUTE MYELOID. CancerMPact® Japan, February 2017.