Biogen shares rally as Alzheimer's drug results show promise

Shares of Biogen and Japanese pharmaceutical company Eisai jumped Wednesday after the drug makers said their potential treatment for Alzheimer's showed promise in slowing the fatal disease that afflicts more than 6 million Americans.  

The companies late Tuesday announced results from a late-stage study of nearly 1,800 people with early-stage Alzheimer's. The infused treatment, lecanemab, curtailed patient decline by 27% when compared to a placebo after 18 months. Patients were monitored using a scale that measures how they do in areas like memory, judgement, problem solving and personal care.

Eisai plans to discuss full results from the research at a conference in late November, and also intends to publish its findings in a peer-reviewed medical journal.

The company is already seeking an accelerated approval from the U.S. Food and Drug Administration, and the agency is expected to decide by early next year. Eisai and Biogen will co-promote the drug.

The initial results appear to be "quite robust" and will likely support regulatory approval, Mizuho Securities analyst Graig Suvannavejh said in a research note.

Alzheimer's is a progressive neurological disease with no known cure. Long-standing treatments on the market just manage symptoms, and researchers don't fully understand what causes the disease.

Beyond the one in three seniors that die with Alzheimer's or another dementia, their toll extends to the more than 11 million Americans who provide unpaid care for those afflicted, according to the Alzheimer's Association. It termed the findings the most encouraging to date for potentially treating underlying causes. 

Biogen's Aduhelm flops

Last year, Biogen's Aduhelm became the first new Alzheimer's drug introduced in nearly two decades. But it has largely flopped after debuting with a price tag of $56,000 annually, which Biogen later slashed.

Doctors have been hesitant to prescribe it, given weak evidence that the drug slows the progression of Alzheimer's. Insurers have blocked or restricted coverage over the drug's high price tag and uncertain benefit. 

Like Aduhelm, Iecanemab, which Eisai developed and ran through clinical trials, seeks to remove a protein called beta-amyloid from the brain.

But Eisai executives say lecanemab focuses more on floating clumps of the protein before it forms a plaque, which is what Aduhelm targets.

Eli Lilly and Co. also is developing a potential treatment, donanemab, that helps clear the protein.

Shares of Cambridge, Massachusetts-based Biogen were lately up 35% at $267.91, after topping $300 in premarket trading. The stock has mostly tumbled since Aduhelm's debut last year.

Eisai Co. shares rose 61% to $66.00, while Indianapolis-based Eli Lilly rose 7%.