Biogen Inc. and Eisai Co. Ltd.'s experimental drug targeting Alzheimer's patients failed to meet the criteria of success in a phase 2 study.
An independent data monitoring board made the determination regarding BAN2401 based on an analysis at 12 months, where success was measured as an 80% or higher probability of achieving a 25% or greater reduction in disease symptoms versus placebo.
The study design included 16 interim analyses that assessed potential for futility or stopping for safety, but neither of these conditions was met. However, the trial will continue and the final analysis will be conducted at 18 months, with data expected in the second half of 2018.
Biogen and Eisai are collaborating to develop BAN2401 and another Alzheimer's drug aducanumab.
The failure was largely expected by investors given the study never stopped at any of the interim analyses and Eisai recently opted into Biogen's aducanumab, Mizuho Biotech analyst Salim Syed said in a research note. He added that data on aducanumab should be viewed separately.
After the news, Biogen's shares were down 3.28% to $322.52 as of market close on Dec. 21.
The trial results do not diminish the probability of success for aducanumab, Barclays analyst Geoffrey Meacham wrote in a Dec. 21 research note. Meacham, who maintains an "overweight" rating on Biogen's stock, believes the news will put modest pressure on the company's shares over the near term as "consensus had baked in just nominal peak sales."
Alzheimer's disease is the most common cause of dementia. The disorder is characterized by the progressive loss of memory and other mental functions.