Key Takeaways

  • In the summer of 2021, the U.S. Food and Drug Administration granted historic accelerated approval for an Alzheimer’s treatment, Aduhelm, designed to slow cognitive decline for persons with the disease.

  • The clinical trials for the new treatment showed that it is best used in persons with early stage Alzheimer’s disease. The drug is not a cure for Alzheimer’s disease.

  • On January 11, 2022, the Centers for Medicare and Medicaid Services (CMS) proposed that this medication would be covered by Medicare only for patients enrolled in qualifying clinical studies.

This article was originally published on June 22, 2021 and then edited to include the Jan. 11, 2022 update from the Centers for Medicare and Medicaid Services.  Read our updated April 18, 2022 article for the latest on Medicare coverage of this class of medications.

You may have heard in the news about a new prescription medication for Alzheimer’s disease that was approved by the U.S. Food and Drug Administration (FDA) last year. Get answers to some commonly asked questions about AduhelmTM, the new Alzheimer's drug, which is the first to be approved in over 18 years for this devastating disease affecting 6.2 million Americans.

What is Aduhelm and how does it work?

The new medicine, called Aduhelm (generic name aducanumab), is the first to attack what many believe is an underlying cause of Alzheimer’s disease. It works by eliminating clumps of a toxic protein believed to destroy neurons in the brain that leads cognitive decline. The proteins, known as beta-amyloid plaques, are common in people with dementia. Aduhelm is a monoclonal antibody (MAB) that stimulates the immune system to target and breakdown these plaques. Other similar medications are in development, including one by the drug company Eli Lilly and Company.

Is the medication a cure for Alzheimer’s disease?

It is important to understand that Aduhelm is NOT a cure for Alzheimer’s. The medication does not reverse the disease’s progression for those who have already developed symptoms of Alzheimer’s disease.

What are the benefits of Aduhelm?

Aduhelm has been shown to break down the amyloid plaques described above but has yet to show clinically significant slowing of cognitive decline, such as memory loss, wandering/getting lost, trouble handling money and paying bills, repeating questions, taking longer to complete normal daily tasks, and personality and behavior changes.  

Who is most likely to benefit from the new Alzheimer's treatment?

Based on the recent updated FDA-approved labeling for AduhelmTM, treatment should be started only in patients with mild cognitive impairment or mild dementia stage of disease. In clinical trials, Aduhelm was tested only in patients with very early-stage Alzheimer’s disease or mild cognitive impairment. The participants in the clinical trials had to undergo PET scans that showed the have amyloid plaques in their brains. The same will be the case once the drug is on the market – amyloid PET scans or other type of imaging will be required before persons with Alzheimer’s are prescribed the medication. The treatment is best for those with the earliest stages of Alzheimer’s disease before brain cells are too damaged to stem the tide of the disease. It has not been tested on persons with later stages of Alzheimer’s disease.

How is Aduhelm given and for how long?

The treatment is given intravenously (through a vein) by infusion over a one hour period once a month for an indefinite period of time.

What are Aduhelm's side effects?

The most common side effect is painful brain swelling, which occurred in about 35% of patients in the clinical trials. Biogen reports that this side effect is most commonly seen as short-term swelling in areas of the brain that usually resolves over time. Some people may also have small spots of bleeding in or on the surface of the brain with the swelling. Over 20% of people in clinical trials had headaches related to the brain swelling. Healthcare providers prescribing Aduhelm will be required to do magnetic resonance imaging (MRI) scans before and during treatment with AduhelmTM to check for brain swelling.

In addition, 8-9% of clinical trial participants experienced confusion, delirium, disorientation, vision changes, and diarrhea. Falls occurred in 15% of the patients taking Aduhelm during the clinical trials. Allergic reactions, such as swelling of the face, lips, mouth, or tongue and hives, can occur during an Aduhelm infusion. 

When will the new Alzheimer's disease treatment be available?

The treatment is currently available.

How much will Aduhelm cost? Will insurance pay for it?

When the medication was first approved by the FDA, Biogen said the cost for a maintenance dose of Aduhelm, based on an average patient’s weight, would be $56,000 per year. In late 2021, Biogen announced that the medication would be cut in half to $28,00 per year. That’s a list price, not the price paid by patients with insurance. The out-of-pocket cost for patients with health insurance will vary depending on insurance coverage. 

For patients on Medicare, the expensive medication would be covered under Medicare Part B since it is given by infusion in a doctor’s office or health care clinic. The co-insurance for beneficiaries enrolled in Original Medicare Part B services is 20%; therefore, the out-of-pocket cost for Medicare beneficiaries will be $5,600 per year. For those with Medicare supplemental or other secondary insurance, the costs may be less. For individuals enrolled in Medicare Advantage plans, the out-of-pocket cost will vary but could be as much as 20%.

In addition to the medication costs, the PET scan required before starting treatment and the MRI scans required will add to the overall costs of treatment.

Who will have access to Aduhelm?

On January 11, 2022, the Centers for Medicare and Medicaid Services or CMS (the federal agency that administers Medicare) proposed that Aduhelm and other medications in this category in the future be covered for people with Medicare only if they are enrolled in qualifying clinical trials or approved studies of the drugs. This decision was based the opinions of experts who reviewed publicly available evidence about Aduhelm and feedback provided by a variety of stakeholders. This is an infrequent decision as CMS does not require participation in clinical studies very often.

This evidence-based approach is being proposed to better understand the benefits versus the harms of the medication before Medicare covers the medication more broadly.

Important questions remain about Aduhelm and the clinical trails will help answer the questions and help CMS determine if Aduhelm and similar medications are reasonable and necessary. The public can provide comments on this proposed coverage determination for the next 30 days. A final decision will be made on April 11 and may be different from what has been proposed by CMS.

The public can submit comments on the proposed National Coverage Determination at:

For patients seeking the medication and wishing to join a clinical trail, all CMS-approved clinical trials would be posted on the CMS Coverage website. Also, National Institutes of Health (NIH) sponsored clinical trials for Aduhelm will be included. Medicare patients participating in these trials would be eligible to receive coverage of the drug, related services, and other routine costs, which may include PET scans and MRIs if required by a clinical trial protocol. 

If this CMS Medicare coverage determination is finalized, it will likely limit the number of people eligible to receive the medication based on where the studies are located. Most clinical studies are run out of major medical centers that will be prepared to meet the governmental requirements for these studies. In addition, Medicare will also limit those eligible for the studies to those with mild forms of cognitive impairment or early stage dementia and those who have amyloid plaques in the brain.

This approach may result in inequitable access to the medication, such as certain geographies where the medical centers are located. CMS has indicated that qualifying studies must enroll a diverse group of patients that is representative of the people in the Medicare program who have Alzheimer’s disease.

Those who are able to afford the medication can pay out-of-pocket for it as well as the costs to administer it by infusion, and the required scans, such as PET scans and MRIs, to monitor amyloid plaques in the brain  and possible side effects.

What is controversial about the approval of Aduhelm?

The accelerated approval by the FDA is based on data from clinical trials showing the effect of Aduhelm on reducing amyloid plaques, an outcome that is thought to lead to a reduction in memory and other problems experienced by those with Alzheimer’s disease. Clinical trials showed only a very small reduction in cognitive loss with some experts saying that the trials fail to make a convincing case for approval. In fact, the FDA Advisory Committee of experts had voted against FDA approval until additional clinical trials are conducted.

Other experts in dementia care believe this approval is an important first step in moving Alzheimer’s disease from a terminal to a manageable illness.

As part of the accelerated approval, Biogen is required to conduct more studies to prove the clinical benefit of Aduhelm in patients with Alzheimer’s disease. Continued approval for Aduhelm as a treatment for Alzheimer’s disease will depend upon more evidence of clinical benefit in these future studies. 

What should I do if I am a person with mild cognitive impairment or a caregiver for someone with mild cognitive impairment?

As is the case with starting any new treatment, it is important to understand the benefits and risks for your or your care recipient’s individual situation. Learn as much as you can about the new medication and speak with your primary care physician about it. Your primary care physician may advise you to see a neurologist if you are not already seeing one. If you are on Medicare and want Medicare to cover the costs of this medication, you will need to enroll in a qualifying clinical trial as described above if the proposed CMS coverage determination is finalized.

Neurologists specialize in caring for persons with Alzheimer’s disease and other nervous system conditions and can best advise you on your options. Do not make any change to medications you are currently taking and continue to practice brain healthy behaviors, such regular physical activity, 7-8 hours of sleep every night, eating a heart healthy or Mediterranean diet, and staying mentally active and socially connected.