Eisai Co., Ltd. (Headquarters: Tokyo, CEO: Haruo Naito, ¡°Eisai¡±) announced today that, at its recent meeting with the U.S. Food and Drug Administration (FDA), the FDA confirmed there was sufficient data to support the advancement of its novel investigational oral beta-secretase cleaving enzyme (BACE) inhibitor E2609 into Phase III clinical studies. E2609 was discovered by Eisai and is being jointly developed by Eisai and Biogen Inc. (Headquarters: Massachusetts, United States, CEO: George A. Scangos, ¡°Biogen¡±) for early Alzheimer¡¯s disease.

Based on the clinical and pre-clinical data presented to the FDA at the Study 202 end of Phase II meeting, the FDA confirmed that the data package was sufficient to commence Phase III studies, and acknowledged the outlines of the two Phase III clinical study protocol designs. The study protocol will be a placebo-controlled design in patients with early Alzheimer¡¯s disease where the treatment group will be administered a dosage of 50 mg/day of E2609 with the primary outcome endpoint assessed at 24 months. The primary endpoint will be the Clinical Dementia Rating Sum of Boxes (CDR-SB), with routine safety assessment.

Following this discussion with the FDA on the Phase III clinical study designs, Eisai and Biogen intend to have similar discussions with the regulatory authorities in Japan and the EU, and to conduct the study as a global, multicenter study.

Study 202 was a multicenter, randomized, double-blind, placebo-controlled parallel-group study to evaluate the safety of E2609 administered in patients with early to moderate Alzheimer¡¯s disease (including prodromal Alzheimer¡¯s disease) with confirmed accumulation of amyloid beta (A¦Â) by PET (positron emission tomography) screening. The study included three doses of E2609: 5, 15, and 50mg/day. Plasma and cerebrospinal fluid (CSF) A¦Â (A¦Â1-x)* levels were measured in patients prior to receiving E2609 and during the study.

The results of an analysis of Study 202 presented at the end of Phase II meeting suggested favorable safety at all doses of E2609 and that total A¦Â levels in the plasma and CSF were reduced in a dose-dependent manner. Furthermore, according to an analysis of safety and pharmacokinetic/pharmacodynamic data from pre-clinical studies as well as Study 202 and Phase I clinical studies overall, the optimal dose of E2609 was identified as 50 mg/day.

Lynn Kramer, M.D., Chief Clinical Officer and Chief Medical Officer of Eisai Neurology Business Group commented, ¡°We believe that the Phase III clinical study design outline agreed upon will enable us to efficiently conduct studies on BACE inhibitors aimed at realizing preemptive medicine, and will accelerate the development of E2609. We are striving to deliver E2609 to patients around the world as soon as possible, and contribute to increasing the benefit for patients.¡±