• Home
  • News
  • Fortune 500
  • Tech
  • Finance
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia
Features

How Biogen scored the most successful Alzheimer’s drug so far

By
Jen Wieczner
Jen Wieczner
Down Arrow Button Icon
By
Jen Wieczner
Jen Wieczner
Down Arrow Button Icon
March 20, 2015, 8:39 PM ET
George Scangos, CEO of Biogen Inc. speaks during Reuters Health Summit in New York
George Scangos, CEO of Biogen Inc. speaks during the Reuters Health Summit in New York, May 10, 2011. Scangos is uncomfortable in the well-appointed office he inherited when he took the top job last July. He is eager to bring greater flexibility and vitality to Biogen, which makes the multiple sclerosis drugs Avonex and Tysabri and is one of the world's biggest biotech companies. REUTERS/Mike Segar (UNITED STATES - Tags: HEALTH BUSINESS) - RTR2M816Photograph by Mike Segar — Reuters

Biogen Idec wowed the market Friday by providing evidence that its Alzheimer’s drug may be the first to successfully treat the underlying cause of the disease.

In a clinical trial, the drug showed a meaningful slowing of the cognitive declines and dementia associated with Alzheimer’s—an up to 82% improvement in mental symptoms compared to the control group after a year of treatment.

Presenting trial data for the developmental drug known as aducanumab, Biogen said that it had significantly reduced amyloid plaque buildup in the brain, which is considered a contributor of Alzheimer’s disease.

While the Cambridge, Mass.-based company still has a long way to go before winning FDA approval for the drug, the phase 1 trial results were so encouraging that some analysts suggested the treatment could eventually be worth at least $10 billion in sales. Biogen’s shares closed 10% higher after the company shared the data at a conference in Nice, France.

An effective treatment for Alzheimer’s has long eluded the pharmaceutical industry. Part of the problem is that researchers have struggled to definitively link a particular gene or marker to the disease. Biogen may have confirmed such a relationship, raising the possibility of treating people with Alzheimer’s by identifying a target for future medications. Drugs that can alleviate dementia and other cognitive symptoms could help the 5 million Americans who have the disease.

Where Biogen (BIIB) may have really excelled, though, was in the design of its clinical trial, rather than the drug itself. To start, the company carefully screened prospective trial participants using PET scans to make sure they actually had the amyloid plaques that the drug targets.

That additional step, say experts, may be why Biogen’s drug achieved a statistically significant benefit while other companies have failed with their experimental treatments, such as Eli Lilly’s solanezumab, which flopped in multiple trials. “Anywhere between 20 to 30% in the trial probably could not have benefited from the therapy,” Andy Acker, manager of the Janus Global Life Science fund, says of the other studies. “That creates a lot of noise.”

Biogen also selected only patients with early or mild forms of Alzheimer’s for its trial, which may have made it easier to show a bigger cognitive improvement. “The magnitude of the efficacy improvements is really striking,” says Mark Schoenebaum, a biotech and pharmaceuticals analyst for Evercore ISI.

And if the company can replicate similarly impressive results in subsequent trials, it may have the very first blockbuster Alzheimer’s drug on its hands. “How valuable would it be to have a drug that actually could address the underlying cause of Alzheimer’s?” muses Acker. Answer: probably somewhere in the billions-of-dollars range.

Watch more business news from Fortune:

About the Author
By Jen Wieczner
See full bioRight Arrow Button Icon

Latest in Features

FeaturesThe Boring Company
Two firefighters suffered chemical burns in a Boring Co. tunnel. Then the Nevada Governor’s office got involved, and the penalties disappeared
By Jessica Mathews and Leo SchwartzNovember 12, 2025
22 days ago
CoreWeave executives pose in front of the Nasdaq building on the day of the company's IPO.
AIData centers
Data-center operator CoreWeave is a stock-market darling. Bears see its finances as emblematic of an AI infrastructure bubble
By Jeremy Kahn and Leo SchwartzNovember 8, 2025
27 days ago
Libery Energy's hydraulic fracturing, or frac, spreads are increasingly electrified with natural gas power, a technology now translating to powering data centers.
Energy
AI’s insatiable need for power is driving an unexpected boom in oil-fracking company stocks 
By Jordan BlumOctober 23, 2025
1 month ago
Politics
Huge AI data centers are turning local elections into fights over the future of energy
By Sharon GoldmanOctober 22, 2025
1 month ago
A plane carrying Donald Trump Jr. arrives in January in Nuuk, Greenland, where he is making a short private visit after his father, President Trump, suggested Washington annex the autonomous Danish territory.
EnergyGreenland
A Texas company plans to drill for oil in Greenland despite a climate change ban and Trump’s desire to annex the territory
By Jordan BlumOctober 22, 2025
1 month ago
Three of the founders of Multiverse Computing.
AIChange the World
From WhatsApp friends to a $500 million–plus valuation: These founders argue their tiny AI models are better for customers and the planet
By Vivienne WaltOctober 9, 2025
2 months ago

Most Popular

placeholder alt text
Economy
Two months into the new fiscal year and the U.S. government is already spending more than $10 billion a week servicing national debt
By Eleanor PringleDecember 4, 2025
20 hours ago
placeholder alt text
Success
‘Godfather of AI’ says Bill Gates and Elon Musk are right about the future of work—but he predicts mass unemployment is on its way
By Preston ForeDecember 4, 2025
16 hours ago
placeholder alt text
Success
Nearly 4 million new manufacturing jobs are coming to America as boomers retire—but it's the one trade job Gen Z doesn't want
By Emma BurleighDecember 4, 2025
16 hours ago
placeholder alt text
North America
Jeff Bezos and Lauren Sánchez Bezos commit $102.5 million to organizations combating homelessness across the U.S.: ‘This is just the beginning’
By Sydney LakeDecember 2, 2025
3 days ago
placeholder alt text
Success
Nvidia CEO Jensen Huang admits he works 7 days a week, including holidays, in a constant 'state of anxiety' out of fear of going bankrupt
By Jessica CoacciDecember 4, 2025
15 hours ago
placeholder alt text
Health
Bill Gates decries ‘significant reversal in child deaths’ as nearly 5 million kids will die before they turn 5 this year
By Nick LichtenbergDecember 4, 2025
1 day ago
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • Future 50
  • World’s Most Admired Companies
  • See All Rankings
Sections
  • Finance
  • Leadership
  • Success
  • Tech
  • Asia
  • Europe
  • Environment
  • Fortune Crypto
  • Health
  • Retail
  • Lifestyle
  • Politics
  • Newsletters
  • Magazine
  • Features
  • Commentary
  • Mpw
  • CEO Initiative
  • Conferences
  • Personal Finance
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
About Us
  • About Us
  • Editorial Calendar
  • Press Center
  • Work At Fortune
  • Diversity And Inclusion
  • Terms And Conditions
  • Site Map

© 2025 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.