Topline results from first of four Phase 3 studies of Pfizer's bapineuzumab for Alzheimer's

Pfizer Inc. (NYSE: PFE) announced today that the co-primary clinical endpoints, change in cognitive and functional performance compared to placebo, were not met in the Janssen Alzheimer Immunotherapy R&D LLC (Janssen AI)-led Phase 3 trial of intravenous (IV) bapineuzumab in patients with mild-to-moderate Alzheimer's disease who carry the ApoE4 (apolipoprotein E epsilon 4) genotype (Study 302). Pfizer and Janssen AI are partners in the Alzheimer's Immunotherapy Program (AIP).

These clinical findings have been shared with regulatory authorities and study investigators so that participants in the ongoing clinical program can be informed. Because in this study clinical efficacy was not demonstrated in ApoE4 carriers, the Janssen AI and Pfizer Joint Steering Committee for the AIP has decided that participants from this study who enrolled in a follow-on extension study will no longer receive doses of bapineuzumab. However, these patients will have a follow-up evaluation.

Based on a comprehensive review of the data by the independent safety monitoring committee, all other ongoing Janssen AI and Pfizer bapineuzumab studies are continuing as planned and without modifications.

Study 302 is the first of four placebo-controlled Phase 3 studies to complete in the comprehensive development program of bapineuzumab IV. Janssen AI is leading two Phase 3 studies of patients who are ApoE4 carriers (Study 302) and non-carriers (Study 301) at sites primarily in North America. Pfizer is conducting two Phase 3 studies of patients who are ApoE4 carriers (Study 3001) and non-carriers (Study 3000) at sites primarily outside of North America.

The Alliance will expedite the completion of an interim analysis for the on-going, Pfizer-conducted Phase 3 study of ApoE4 carriers (Study 3001) based on the results of Study 302.

The topline results from Study 301 in patients with mild-to-moderate Alzheimer's disease who do not carry the ApoE4 genotype are expected to be announced later this summer.

"While we are disappointed in the topline results of Study 302, a more complete understanding of bapineuzumab and its potential utility in mild-to-moderate Alzheimer's disease will be gained following the availability of additional data, including data from the soon-to-be available non-carrier Study 301," said Steven J. Romano, M.D., senior vice president, head, Medicines Development Group, Global Primary Care Business Unit, Pfizer Inc. "We recognize that Alzheimer's disease is very complex, but Pfizer, along with our partner Janssen AI, remains committed to advancing the science of Alzheimer's disease, with the ultimate goal of delivering innovative and meaningful new treatment options to patients."

Data from both the ApoE4 carrier (Study 302) and non-carrier (Study 301) studies have been accepted as a late-breaker and will be presented in September at the European Federation of Neurological Societies meeting in Stockholm.

The presence of the ApoE epsilon 4 genotype is a genetic risk factor for Alzheimer's disease and is associated with increased beta-amyloid plaques in the brains of patients with the disease. Topline results of Study 302 indicate that among patients treated with bapineuzumab IV the most commonly observed serious adverse events which occurred more commonly than placebo and with an incidence of at least 1 percent were ARIA-E and dehydration. ARIA-E (amyloid-related imaging abnormalities-edema or effusion) refers to changes in the brain that may be due to fluid (water and protein) leaking from blood vessels, which can be detected using magnetic resonance imaging (MRI) of the brain.