Biogen Plunges 25% After Company Discontinues Alzheimer's Drug Study

Shares of neuroscience company Biogen Inc BIIB lost more than 25 percent Thursday morning after the company said it will discontinue an ongoing Alzheimer's drug study.

What Happened

Biogen and its partner Japan-based Eisai said they will discontinue an ongoing global Phase 3 trial of its therapy aducanumab. The investigational compound was meant to slow the progression of Alzheimer's by reducing amyloid plaques present in the brain.

The companies said the decision to end their trial came after an independent data monitoring found the trials were unlikely to achieve their primary endpoint upon completion.

Why It's Important

Thursday's announcement is discouraging as Aducanumab had high hopes of finally being the therapy to halt the progression of Alzheimer's, according to Stat's Adam Feuerstein.

Biogen "bet heavily" on the therapy and pushed against calls from investors to diversify its portfolio to protect against potential risk, Feuerstein said. As such, the latest developments raise "uncomfortable questions" management will need to address over the coming days.

What's Next

Biogen CEO Michel Vounatsos said in the press release the company will continue advancing its pipeline of therapies to treat Alzheimer's and innovate medicines for patients that suffer from diseases with large amounts of unmet needs.

Biogen's stock traded down 27 percent to $233.89 per share at time of publication.

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