Biogen, Eisai Claim Success in New Analysis of Failed Alzheimer’s Study

Xconomy Boston — 

Biogen and Eisai are reporting encouraging data from a mid-stage study in Alzheimer’s disease, reviving hopes for a drug and an approach to treating the disease that many had declared a failure.

The drug, BAN2401, had in fact failed in clinical studies. Last December, Biogen (NASDAQ: BIIB) and Eisai reported that the drug did not meet the main goal of beating a placebo after 12 months of treatment in a Phase 2 study. Despite that result, the companies said they would continue the study for another six months. Late Thursday, the companies said they now have promising early results after reviewing data from patients treated for 18 months. In those who received the highest dose of the drug, the analysis showed a statistically significant slowing of the progression of the disease, the companies said.

Full data from the analysis were not released. Biogen and Eisai said that more detailed study results will be presented at future academic conferences. But investors welcomed the preliminary results, boosting Biogen shares by more than 20 percent in trading Friday morning.

BAN2401 is an antibody drug that binds to amyloid beta plaque, a protein that builds up in the brains of Alzheimer’s patients. The drug was developed to break up this protein buildup. Biogen and Eisai tested the drug in a double-blind, placebo-controlled study that enrolled 856 patients. Patients were randomized to receive one of five doses of the drug, or a placebo. The study used an “adaptive” design that allows the clinical researchers to make adjustments in the middle of the study, an approach intended to more quickly find the best dose of a drug. The drug’s effect was evaluated with imaging technologies to measure the reduction of amyloid in the brain, as well as with a combination of assessments used to test cognition in Alzheimer’s patients.

Biogen and Eisai said that the final analysis showed a statistically significant improvement in patient cognition scores. The companies also reported a statistically significant reduction in the amount of amyloid buildup in the brain. They added that patients who received the highest dose of BAN2401 started to show benefit in cognition as early as six months after starting treatment. The companies did not say how many patients were in the group that received the highest dose of the drug.

The preliminary results for BAN2401 revive some hope for the theory that amyloid is a major factor in the development of Alzheimer’s. A number of amyloid-targeting drugs have failed spectacularly in late-stage studies, including solanezumab from Eli Lilly (NYSE: LLY) and intepirdine from Axovant Sciences (NASDAQ: AXON). In light of those failures, some researchers are advocating a return to approaches that target the part of the brain where Alzheimer’s disease strikes first.

BAN2401, originally developed by Sweden-based BioArctic Neuroscience, was acquired by Eisai in 2007. That drug became part of a wide-ranging Alzheimer’s partnership between Eisai and Biogen that started in 2014. Under that agreement, the companies will work together to test, and potentially commercialize, two drugs from Eisai and two from Biogen. Here’s more on the Biogen/Eisai Alzheimer’s alliance.

Photo of amyloid plaques by Wikimedia user Jensflorian via a Creative Commons license