Alzheimer’s breakthrough: Eisai, Biogen’s new drug, lecanemab, shows promising early study results

CHICAGO– Shares of Biogen and other drugmakers researching Alzheimer’s disease soared Wednesday after Japan’s Eisai Co. said in a late-stage study its potential treatment appears to be slowing the deadly disease.

The drugmaker said early results showed its treatment, lecanemab, reduced the patient’s clinical decline by 27% compared to a placebo or counterfeit drug after 18 months of infusion treatment.

Eisai late Tuesday announced results from a global study of nearly 1,800 people with early-stage Alzheimer’s.

Patients were monitored using a scale that measures mental decline and their ability to do daily activities such as dressing or eating.

Eisai Co.Ltd. announced that it would discuss the full research results at a conference in late November. There are also plans to publish the results in a peer-reviewed medical journal.

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The company is already seeking accelerated approval from the US Food and Drug Administration, and the agency is expected to make a decision early next year. Eisai and Biogen will co-promote the drug.

Researchers typically advise caution when evaluating a study until the full results are published. But initial results appear to be “fairly robust” and likely to support regulatory approval, Graig Suvannavejh, an analyst at Mizuho Securities, said in a research note.

A statement from the Alzheimer’s Association called the results the most encouraging yet for potential treatments for the underlying causes of the disease.

“Receiving a diagnosis is a death sentence, so when new treatments like these come out, it lets families know there is hope,” said Delia Jervier, executive director of the Illinois Alzheimer’s Association.

But the neurologist Dr. Marsel Mesulam warns that the drug will be cumbersome to administer and comes with some side effects such as brain swelling and cerebral hemorrhage. For some families, the risks of the treatment might outweigh the benefits, he says.

“The problem is how to recommend something that is little and that neither the patient nor the family can really recognize and that has side effects,” said Mesulam, who directs Northwestern University’s Center for Cognitive Neurology and Alzheimer’s.

Approximately 6 million people in the United States and many more worldwide have Alzheimer’s, which progressively attacks areas of the brain needed for memory, reasoning, communication, and basic daily tasks.

Alzheimer’s has no known cure. Longstanding treatments on the market only treat the symptoms, and researchers don’t fully understand what causes the disease.

Last year, Biogen’s Aduhelm became the first new Alzheimer’s drug to be launched in nearly two decades. But it largely flopped after debuting at a $56,000-per-year price tag that Biogen later cut.

Doctors have been reluctant to prescribe it due to weak evidence the drug slows the progression of Alzheimer’s. Insurers have blocked or restricted coverage over concerns about the drug’s high price and uncertain benefits.

Earlier this year, the state’s Medicare program imposed severe restrictions on who can get the drug, wiping out most of its potential U.S. market. Biogen then announced that it would stop most of its spending on treatment.

Like Aduhelm, lecanemab developed by Eisai aims to clear a protein called beta-amyloid from the brain.

The protein forms a plaque that researchers believe contributes to Alzheimer’s. They also point to other possible factors such as family history and chronic conditions such as diabetes.

Eisai executives say lecanemab focuses more on floating clumps of the protein before it forms the plaque, which Aduhelm is targeting.

Eli Lilly and co. are also developing a potential treatment, donanemab, that targets the protein.

Biogen Inc., based in Cambridge, Massachusetts, was up 40% to close at $276.61 on Wednesday. The stock had fallen sharply since Aduhelm’s debut last year.

Indianapolis-based Eli Lilly and Co. was up 7.5%.

ABC7 Chicago contributed to this report