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Why Is the FDA Approval of a New Alzheimer's Drug So Controversial?

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Key Takeaways

  • The FDA recently approved Aduhelm as the first new drug for Alzheimer’s disease in almost 20 years. 
  • The drug is intended to slow disease progression by reducing plaques on the brain.
  • Because there is no evidence that Aduhelm can offer clinical benefit and improve Alzheimer's symptoms in real life, many experts are criticizing the FDA for this approval.
  • The FDA did not define which patients are most appropriate for Aduhelm, but clinical trials included people with mild cognitive impairment.

On Monday, June 7, the Food and Drug Administration (FDA) approved Aduhelm (aducanumab) for the treatment of Alzheimer’s disease, a condition that affects over 6 million people in the United States. The drug is a first-of-its kind therapy, according to the FDA. 

“Currently available therapies only treat symptoms of the disease; this treatment option is the first therapy to target and affect the underlying disease process of Alzheimer’s,” said Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research, in a statement.

The drug is intended to slow the progression of Alzheimer's disease. It is not a cure.  

The news about Aduhelm’s approval is both exciting and controversial. It's exciting because it is the first new drug approved to treat Alzheimer’s since 2003. It’s controversial because it’s not clear from the clinical trial that the drug will actually work. Last year, an FDA panel concluded there wasn't enough evidence to prove the drug was effective.

What Is Alzheimer's Disease?

Alzheimer’s disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills. While the specific causes of Alzheimer’s disease are not fully known, according to the Alzheimer’s Association, it is characterized by changes in the brain—including the buildup of a protein called beta-amyloid plaque.

Aduhelm works by reducing beta-amyloid plaque, according to the FDA. 

Researchers evaluated Aduhelm in three studies that enrolled close to 3,500 patients in double-blind, randomized, placebo-controlled studies of different doses of the drug in patients with Alzheimer’s disease. According to the FDA, patients who received the drug had reductions of beta-amyloid plaque, while patients who received a placebo did not have amyloid beta-amyloid reductions, both based on imaging exams called PET (positron emission tomography) scans. 

The reduction in amyloid—rather than an improvement in memory or thinking skills—led to the FDA approval. And that's why some experts are concerned. As part of its approval, the FDA is requiring Biogen, Aduhelm’s manufacturer, to conduct a new randomized, controlled clinical trial to verify that the drug can actually improve or reduce Alzheimer's symptoms.

“If the trial fails to verify clinical benefit, the FDA may initiate proceedings to withdraw approval of the drug,” says an FDA statement.

Reactions to the Approval Are Mixed

In a statement released on Monday, the Alzheimer’s Association, which provided some of the funding for the Aduhelm clinical trials, showed enthusiasm for the drug news. But the organization was also cautious in its reaction to the significance of the approval. It's the first step in the right direction, not an immediate game-changer.

“This FDA drug approval ushers in a new era in Alzheimer’s treatment and research,” said Maria C. Carrillo, PhD, Alzheimer’s Association chief science officer. “History has shown us that approvals of the first drug in a new category invigorates the field, increases investments in new treatments and encourages greater innovation. We are hopeful and this is the beginning—both for this drug and for better treatments for Alzheimer’s.”

But Public Citizen, a consumer advocacy organization based in Washington, DC, was highly critical of the FDA’s decision to approve the drug.

Michael Carome, MD, director of the organization’s health research group, tells Verywell that the approval came “despite the nearly unanimous conclusion of an independent panel of experts convened by the agency in November that there want not enough evidence presented showing the drug to be effective.” 

The panel of experts were members of a voluntary FDA advisory committee. The agency convenes such a panel before approving drugs and devices, but is not required to follow the panel’s guidance. 

Will the Drug Work?

Alzheimer’s experts say the newly-approved drug represents a positive step, though hardly an end to the debilitating disease.

“What we call dementia—cognitive impairment in the brain—is likely multifactorial,” Ronald Peterson, MD, PhD, director of the Mayo Clinic Alzheimer's Disease Research Center, tell Verywell. “Like treating blood pressure, what’s likely necessary to treat Alzheimer’s is a cocktail of several drugs with different mechanisms of action.” 

What to Know About Taking Aduhelm

Aduhelm is given as an IV infusion every four weeks. It was not tested on people with late progression of Alzheimer's, but the FDA prescribing information does not put parameters around who should or shouldn't receive the drug.

The drug could cost $56,000 per year, according to Biogen. “The out-of-pocket cost for patients with insurance will vary depending on their coverage,” says a statement released on Monday.

The FDA included a warning that some patients may have “temporary swelling in areas of the brain that usually resolves over time.” During clinical trials, brain swelling was more common in people with a genetic predisposition to Alzheimer's disease. Other side effects may include:

  • Headache
  • Confusion
  • Dizziness
  • Vision changes
  • Diarrhea

A Word From Our Chief Medical Officer

Aduhelm is very pricey, as most drugs are when they enter the market. That's because insurance companies need to figure out how much they are going to cover how much the drug is actually being prescribed. It's a complex equation between drug companies, insurers, pharmacies, and physicians. Usually, it takes up to a year for price and coverage decisions to stabilize, though it often depends on the market, the disease, and who it impacts.

Jessica Shepherd, MD
Chief Medical Officer, Verywell Health
Dr. Jessica Shepherd, MD
Personal Detail

Dr. Shepherd is board-certified in obstetrics-gynecology and is affiliated with Baylor University Medical Center in Dallas, Texas. Dr. Shepherd appears regularly as an expert on Good Morning America, The Today Show, and more.

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  1. Food and Drug Administration. FDA grants accelerated approval for Alzheimer’s drug. Published June 7, 2021.

  2. Biogen. Biogen and Eisai launch multiple initiatives to help patients with Alzheimer’s disease access Aduhelm. Published June 7, 2021.