BIIB Biogen Inc

By Colin Kellaher 

Biogen Inc. said it plans to pursue regulatory approval for aducanumab, an investigational treatment for early Alzheimer's disease, after pulling the plug on phase 3 studies of the drug earlier this year.

Shares of Biogen surged 40% in premarket trading, putting the company on track to add more than $16 billion in market value. When the company and partner Eisai & Co. in March said they would terminate the late-stage studies, Biogen lost about $18 billion in market value.

The Cambridge, Mass., biopharmaceutical company said Tuesday that the reversal follows an analysis of a larger dataset from the studies that showed aducanumab reduced clinical decline in patients with early Alzheimer's disease as measured by the prespecified primary and secondary endpoints.

Biogen said it conducted the new analysis in consultation with the U.S. Food and Drug Administration, and it included data that became available after the prespecified futility analysis. In March, the company and Eisai determined the drug would likely fail to help patients.

The company said that based on discussions with the FDA, it plans to file a biologics license application for aducanumab in early 2020 and said it would continue talks with regulatory authorities in international markets, including Europe and Japan.

The reversal brings renewed hope to the hypothesis that has informed much of the recent research and investment into potential Alzheimer's drugs: that the buildup in the brain of a sticky substance called Beta amyloid plays a pivotal role in the disease.

Drugs like aducanumab have targeted the sticky tangles with the goal of slowing or halting the progression of the disorder. But a number of drugs developed with the idea in mind have failed.

Aducanumab was an important bet for Biogen because the biotech company has been looking to Alzheimer's disease treatment to fuel future revenue growth, especially as competition eats into sales of its core franchise of drugs treating multiple sclerosis.

Many investors were also taken by the company's wager on Alzheimer's. The massive market opportunity treating the memory-robbing disease -- potentially worth billions of dollars a year in sales -- as well as some promising data from early-stage studies attracted new investors to the company and helped drive up its share price.

Excited, too, by the potential opportunity, Biogen invested heavily in recent years to enroll thousands of patients in late-stage studies of aducanumab, some analysts said.

Biogen and Eisai, which had worked jointly on developing aducanumab since October 2017, had been studying it in the early stage of Alzheimer's. Researchers hypothesized that using the drug early in the disease might be a more effective avenue for amyloid-targeting therapy after previous such treatments at later stages had failed.

Write to Colin Kellaher at colin.kellaher@wsj.com

(END) Dow Jones Newswires

October 22, 2019 08:32 ET (12:32 GMT)

Copyright (c) 2019 Dow Jones & Company, Inc.