Backing BACE inhibitors

TOKYO & CAMBRIDGE, Mass.—March opened with news that Eisai Co. Ltd. and Biogen Idec will be collaborating on the development and commercialization of two of Eisai’s clinical candidates for the treatment of Alzheimer’s disease (AD): E2609, a ß-site amyloid precursor protein cleaving enzyme (BACE) inhibitor, and BAN2401, an anti-Aß antibody. Both candidates have the potential to reduce the amyloid beta plaques that develop in the brain of Alzheimer’s patients and stop the formation of new plaques.

“There exists an urgent need to develop AD therapies that suppress disease progression in order to effectively alleviate both the emotional burden of suffering and uncertainty experienced by patients and their families, as well as the financial burden on overall society in terms of the huge costs of nursing and patient care,” Haruo Naito, president and CEO of Eisai, commented in a statement. “Eisai remains deeply focused on the development of such therapies based on the knowledge and experience it has accumulated through its development of the anti-AD agent Aricept. Through our collaboration with Biogen Idec, a company that specializes in neurodegenerative diseases, I believe we will be able to further enhance our existing R&D capacities for developing next-generation AD treatments, thereby accelerating the development of promising therapies and increasing the benefits provided to patients with AD worldwide.”

Per the terms of the agreement, Biogen Idec will pay Eisai an upfront payment as well as a set amount of development, approval and commercial milestone payments. Eisai will have an option to jointly develop and commercialize two of Biogen Idec’s candidates for Alzheimer’s disease: the anti-amyloid beta antibody BIIB037—a human monoclonal antibody licensed from Neurimmune and believed to bind to and eliminate amyloid plaques—and an anti-tau monoclonal antibody. Eisai will also have an option to receive a one-time payment from Biogen Idec related to joint development and commercialization activities in Japan.

Eisai will be the operational and regulatory lead as the companies co-develop E2609 and BAN2401, and will also be responsible for securing marketing authorizations for them worldwide. Eisai and Biogen Idec will co-promote the products in major markets, such as the United States and the European Union, once they have received marketing approval. The partners will share overall costs and research and development expenses, with Eisai booking all sales for the companies and profits split between them.

“This collaboration is a natural fit with our mission to develop therapies for patients with severe neurodegenerative diseases,” Dr. George A. Scangos, CEO of Biogen Idec, said in a news release. “Eisai’s candidates have demonstrated compelling early data and complement out AD research while extending our pipeline in this critical area. Eisai is a pioneer in successfully developing and commercializing AD treatments. This history, combined with their strong scientific heritage, geographical reach and unwavering commitment to the AD community, makes Eisai an excellent collaboration partner to help drive our mission.”

Zacks Equity Research also has a fairly positive take on the deal, noting that they are “pleased with Biogen’s effort to boost its neurodegenerative disease pipeline … However, we note that the successful development of therapies for the treatment of Alzheimer’s disease is challenging and several companies including Eli Lilly and Co. have failed in developing treatments for the same.”

Efforts in treating Alzheimer’s disease generally focus on preventing the formation of the amyloid beta plaques and/or breaking up existing plaques. BACE inhibitors are thought to have potential in treating Alzheimer’s by targeting beta secretase, which in turn hampers the mechanism that creates amyloid beta. There are some concerns, however, as some scientists are have raised concerns regarding BACE inhibitors interfering with myelination.

Despite those concerns, Eisai and Biogen Idec are not alone in their interest in this type of drug, as both Merck and AstraZeneca are advancing BACE inhibitors of their own. Other companies are pursuing these compounds as well, though with less luck; Eli Lilly’s version of a BACE inhibitor failed in the face of liver toxicity in patients, and Roche recently ended its early-stage program for a BACE inhibitor without explanation.

According to the Alzheimer’s Association, more than 5 million people in the United States have Alzheimer’s disease, while Alzheimer’s Disease International estimates that approximately 36 million people have Alzheimer’s disease (or a related dementia) worldwide.