Biogen Cancels Major Alzheimer's Drug Project

Biogen Inc. plummeted after the biotechnology giant said that its experimental Alzheimer’s drug was unlikely to be effective and that it was halting its research, in another setback for drugmakers’ efforts to find a therapy for the neurodegenerative ailment.

The Cambridge, Massachusetts-based company and partner Eisai Co. said Thursday that they would discontinue two late-stage trials designed to evaluate the efficacy and safety of the drug, aducanumab. The results showed that the drug was unlikely to help patients, the companies said in a statement. The tests didn’t reveal serious safety concerns.

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“This disappointing news confirms the complexity of treating Alzheimer’s disease and the need to further advance knowledge in neuroscience,” said Michel Vounatsos, Biogen’s chief executive officer.

Biogen is still studying other, earlier-stage compounds, and is continuing to work with Eisai on two other drugs, said David Caouette, a Biogen spokesman. Caouette declined to say whether the failure would affect a decision on whether to continue with plans for two other Alzheimer’s drugs, known as BAN2401 and elenbecestat.

Eisai declined to immediately comment.

The development will raise questions about Biogen’s future. It’s one of a handful of large biotech firms whose market value has been highly dependent on experimental drugs making it to market — and selling well once they arrive in pharmacies. But the magnitude of the blow Thursday could make Biogen vulnerable to acquisition by a bigger suitor, or force it to go shopping for a large enough asset to replenish its labs with something of similar potential.

The development is a “transformative failure for Biogen’s pipeline,” said Brian Abrahams, an analyst at RBC Capital Markets, who had the equivalent of a hold rating on the stock.

For drugmakers, expensive, ambitious attempts to find an effective treatment for Alzheimer’s have failed again and again. Drugs that looked promising in early tests have come up short when tried in larger groups, frustrating pharmaceutical executives, doctors and patients. Last year, Pfizer Inc. stopped trying entirely to find Alzheimer’s therapies, shutting down its research on both it and Parkinson’s disease and cutting about 300 jobs.

Like many others, Biogen’s aducanumab drug targeted a compound in the brain known as beta amyloid. Biogen had been developing aducanumab largely on its own until 2017, when it agreed to work with Eisai.

Eisai’s BAN2401 drug works to clear beta amyloid from the brain.

Another Eisai drug, elenbecestat, is designed to keep beta amyloid plaques from forming in the brain in the first place.