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October 24, 2019

Biogen reverses course and will seek FDA approval for Alzheimer's drug

Daily Briefing

    Biogen on Tuesday announced that it will seek FDA approval for aducanumab, an Alzheimer's drug that originally had been labeled a failure after the company in March announced trials of the drug had not shown clinical benefits.

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    Biogen developed aducanumab alongside Japan-based Eisai. The drug is aimed to treat Alzheimer's disease by targeting and removing the beta-amyloid that accumulates in the brains of Alzheimer's patients. Researchers have hypothesized that the buildup in the brain from the beta-amyloid is responsible for the cognitive decline seen in Alzheimer's patients.

    The companies enrolled in their trials patients who exhibited early signs of Alzheimer's disease to test whether aducanumab could remove the buildup and improve patients' cognitive abilities.

    But an independent analysis determined the drug likely would not be successful in the trials. As such, the companies in March announced they would end two late-stage clinical trials evaluating the drug.

    Biogen reverses course

    However, on Tuesday Biogen said it would seek FDA approval for the drug after a closer look at its study data determined that aducanumab showed some effect in patients who received higher doses in one of the trials.

    "[A] new analysis of larger dataset showed that aducanumab reduced clinical decline in patients with early Alzheimer's disease as measured by the pre-specified primary and secondary endpoints," the company said.

    Biogen added that, based on discussions it has had with FDA, it plans to submit aducanumab's application by early 2020 and will continue talking with regulatory authorities in other countries. If approved, aducanumab would mark the first drug able to slow cognitive decline in Alzheimer's patients.


    In light of the new data, some experts have expressed cautious optimism about aducanumab. Zaven Khachaturian, editor-in-chief of Alzheimer's & Dementia, said the data so far "looks pretty impressive," but added that Biogen only released the "show-and-tell for investors."

    "If the findings hold, that would be great," Khachaturian added. "Even if it works on a small subset of patients, it is good news. Given the heterogeneity of the disease, it would be unreasonable to expect that it would work on every Alzheimer's" patient.

    Eric Reiman, executive director of Banner Health's Alzheimer's Institute, said, "We need to see the data … to better understand the full implications. But this news provides a shot in [the] arm at the right time for amyloid-focused research, giving hope to those currently impacted by this terrible disease as we actively explore implications for future prevention trials."

    But Ronald Petersen, an Alzheimer's researcher at the Mayo Clinic who consults for Biogen, noted that the drugmaker has yet to convince FDA of aducanumab's efficacy. "They are just allowed to file—no guarantees on approval," he said.

    Separately, P. Murali Doraiswamy, professor of psychiatry and behavioral sciences at Duke University School of Medicine, pointed out that Biogen's plan to use two studies that have been discontinued to get a new drug approved is unusual and potentially unprecedented. Doraiswamy also said that making public the fact the studies failed could introduce bias into the trial investigators' results.

    Meanwhile, Geoffrey Porges, an analyst at SVB Leerink, said he's worried about the potential economic impact of aducanumab's potential approval could have on the health care system.

    "The breakthrough medicines that make a really big difference are expensive enough," he said. "But here you could have millions of patients using a medicine with what appears to be a fairly modest effect, if any effect. Is that the type of thing we should be bankrupting Medicaid for?" (Walker, Wall Street Journal, 10/22; George, MedPage Today, 10/22; Owens, "Vitals," Axios, 10/23; Kolata, New York Times, 10/22; Grant, Wall Street Journal, 10/22;, accessed 10/23).

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