Biogen's stock craters on Alzheimer’s drug failure

Shares of Biogen were on track for the largest decline in a decade on Thursday after the biotech firm and its Japanese partner Eisai halted advanced trials of an experimental treatment for Alzheimer’s.

The setback is the latest in a series of failures in the industry's quest to find a cure for the degenerative disease that could impact as many as 14 million Americans by 2050.

Stock for the Cambridge-based company declined as much as 29 percent – a roughly $17 billion loss -- on the news, which came after an independent analysis indicated that trials of aducanumab were unlikely to meet the stated goals. No safety issues were uncovered.

Ticker Security Last Change Change %
BIIB BIOGEN INC. 226.45 +1.43 +0.64%

“This disappointing news confirms the complexity of treating Alzheimer’s disease and the need to further advance knowledge in neuroscience,” CEO Michel Vounatsos said in a statement. “Biogen’s history has been based on pioneering innovation, learning from successes and setbacks.”

Expectations for Biogen’s Alzheimer’s treatment were sky-high, with the potential for as much as $12 billion in annual sales. The loss leaves one of the world’s largest biotech firms without any major blockbuster treatments and a slew of unapproved drugs in its pipeline.

The saga highlights the difficulty the sector is facing in trying to treat Alzheimer’s -- a complicated disease that is thought to be easier to address in earlier stages, similar to heart disease.

With its drug, Biogen aimed to remove the buildup of one of the proteins in the brain that scientists believe underscore the development of the disease.


A slew of other top companies, including Eli Lilly & Co., AstraZeneca and Merck, have all abandoned trials of experimental treatments for Alzheimer’s.