Biogen, Eisai Alzheimer’s Drug Fails First Test But Study Continues

Xconomy Boston — 

The lead drug in a wide-ranging Alzheimer’s disease collaboration between Biogen and Eisai has flunked its first test, falling short of its main goal in a mid-stage clinical trial.

Biogen (NASDAQ: BIIB) and Eisai said Thursday an independent interim analysis at 12 months found that the drug BAN2401 failed to show enough of a change on assessment scores used to evaluate patients in the early stages of Alzheimer’s disease. But the companies will continue the study to gather more data.

BAN2401 is a monoclonal antibody that binds to amyloid beta plaque to break up the accumulation of this protein on the brain—a characteristic of Alzheimer’s. Eisai acquired the drug in a 2007 deal with Sweden-based BioArctic Neuroscience. Cambridge, MA-based Biogen and Eisai began their Alzheimer’s collaboration in 2014, a pact that laid the groundwork for testing, and potentially commercializing, two of Eisai’s compounds and two of Biogen’s compounds.

The Phase 2 study testing BAN2401 enrolled 856 patients with mild Alzheimer’s disease who showed indicators for amyloid. The patients were randomized to receive either the study drug or a placebo. The “adaptive clinical trial,” which allows trial leaders to evaluate and tweak the study partway through, was designed to offer a faster and more efficient way of finding the right dose of the drug. The design included 16 interim analysis points at which the study could be stopped either for futility or safety. A clinically significant difference was defined as a 25 percent or greater reduction in the rate of decline in the Alzheimer’s assessment scores, compared to a placebo.

Though the drug did not reach this goal in the Alzheimer’s assessments, Biogen and Eisai said that the drug did not meet the conditions for stopping the trial for either futility or safety. Therefore, the companies plan to continue for another six months. With 18 months of data, they plan to do a full analysis in hopes of showing clinically significant results.

In a research note, Evercore ISI analyst Umer Raffat emphasized that the trial is not over and that there’s still a chance the trial could hit its mark at 18 months. If BAN2401 efficacy scores are 25 percent or greater than those of a placebo, and the drug shows very limited abnormal neuroimaging differences in patients, the drug is likely headed to a Phase 3 study, he wrote.

Barclays, in a research note, said that the interim results for BAN2401 may rekindle the debate about whether amyloid is a major factor in Alzheimer’s. A number of amyloid-targeting drugs have failed in clinical trials, including Eli Lilly’s (NYSE: LLY) solanezumab, and Axovant’s (NASDAQ: AXON) intepirdine. In light of these failures, some researchers have called for a back-to-basics approach to Alzheimer’s drug research and development. But Biogen is continuing to press forward with its own anti-amyloid drug, aducanumab.

Biogen and Eisai expect to have full results from the BAN2401 trial in the second half of next year.

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