CAMBRIDGE (CBS) – The FDA approved the first new drug for Alzheimer’s disease in nearly 20 years Monday, even though the decision to greenlight Biogen’s new drug has been fraught with controversy.

The drug, a monoclonal antibody called aducanumab or Aduhelm, is designed to remove the clumps of beta amyloid proteins that accumulate in the brains of people with Alzheimer’s. The hope is to slow memory loss and thinking problems in patients in the early stages of disease. Given as a monthly infusion, it’s the first approved treatment that targets the underlying disease process rather than just treating the symptoms of dementia.

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But while patients and some neurologists are hailing the new drug, many experts aren’t.

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In fact, the FDA’s advisory committee overwhelmingly voted against it. Skeptics say there just isn’t enough clinical evidence that the drug works and that the potential benefits are so small they don’t outweigh the risks which include swelling or bleeding in the brain. There is also concern that approving the drug would make it harder to enroll patients in studies for other drugs that could ultimately work better.

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The FDA granted approval with the agreement that Cambridge-based Biogen would conduct a new large clinical trial. The drug will be available to patients during that time, but if the trial fails to show the drug improves symptoms, the FDA could rescind its approval.

Dr. Mallika Marshall