Eisai, Biogen Halt Phase III Studies of Alzheimer's Drug

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The Phase III clinical studies for the drug candidate, elenbecestat, were discontinued based on a recommendation by a data safety monitoring board.

Eisai and Biogen announced on Sept. 13, 2019 the decision to discontinue Phase III clinical studies of elenbecestat, an investigational oral beta amyloid cleaving enzyme (BACE) inhibitor, in patients with early Alzheimer's disease (AD). The decision is based on the results of a safety review conducted by a data safety monitoring board (DSMB), which recommended the discontinuation of the trials because of an unfavorable risk-benefit ratio. Detailed data of these studies will be presented at future medical meetings.

As part of this decision, the long-term extension of a Phase II clinical trial of elenbecestat will also be discontinued. This determination does not impact the program of an anti-amyloid beta (Aβ) protofibril monoclonal antibody, BAN2401, currently in development and for which a Phase III trial in AD will continue.

The Phase III clinical trial program for elenbecestat consisted of two global Phase III clinical studies with identical protocols. Both studies were multicenter, placebo-controlled, double-blind, parallel-group Phase III clinical studies designed to assess the efficacy and safety of the drug for treatment in a total of approximately 2100 patients with mild cognitive impairment or mild AD (collectively known as early AD) with confirmed amyloid pathology in the brain.


“We would like to thank the patients and the families, as well as medical professionals, that participated in the [studies]. Without their contributions we would not be able to advance Alzheimer’s disease research. We are very disappointed with the news and intend to learn from these data and continue engaging with patients and investigators to pursue the discovery of new medicines for Alzheimer’s disease,” said Dr. Lynn Kramer, chief clinical officer, Neurology Business Group, Eisai, in a company press release.

Source: Eisai