Scientific Coalition Comment on CMS’s Proposed Decision Memo on Monoclonal Antibodies Directed Against Amyloid for the Treatment of Alzheimer’s Disease

February 10, 2022

As organizations committed to scientific integrity, we are providing these public comments on the National Coverage Analysis Proposed Decision Memo from the Centers for Medicare and Medicaid Services (CMS). This decision relates to coverage of Aduhelm and similar unproven medical products for the treatment of Alzheimer’s disease.

We share the view of scientists and researchers across the country that the FDA approval of Aduhelm was not scientifically sound and sets a dangerous precedent for other medical products. The clinical trial data that the manufacturer submitted to the FDA did not meet FDA’s standards of safety and efficacy, resulting in a unanimous vote against Aduhelm by the FDA’s scientific advisory committee.  We therefore strongly support the CMS proposed decision to limit the coverage of these Alzheimer’s drugs to patients participating in clinical trials, as a way to determine if the drug is safe and effective for Medicare patients before covering the cost for millions of patients. This will provide the scientific evidence needed so that patients and family members can make informed decisions based on unbiased information – essential criteria for all medical products, and not only those for Alzheimer’s disease.

Our nonprofit organizations also support the scientific importance of diversity in clinical trials used as the basis of FDA decisions. Fewer than 4% of the patients in the Aduhelm clinical trials were Black or Hispanic, making it impossible to determine safety or efficacy for those populations. Moreover, the data from the Aduhelm studies submitted to the FDA were based on patients representing a small minority (15%) of the types of Medicare beneficiaries who have mild Alzheimer’s disease, excluding many with common chronic health conditions.

We recommend the following to ensure unbiased scientific evidence:

  1. Enforcement of requirements for diversity 

CMS’s proposal mandates that CMS-funded trials must include a nationally representative population of people with Alzheimer’s disease. We urge that this diversity include a substantial number of patients in different racial, ethnic, and age groups to ensure that there is enough statistical power to determine safety and efficacy for each of the major demographic groups. CMS should specify how they will ensure that the study participants represent the co-morbidities typical of Alzheimer’s patients, while protecting patients from harm. Since CMS plans to restrict clinical trials to the most appropriately selected treatment centers, that should ensure the diversity that is needed.

  1. Safety Data

In the original Aduhelm clinical trials, 41% of patients experienced brain swelling or brain bleeds. Other side effects included headaches, dizziness, confusion, and an altered mental state. It was unclear which patients were at greatest risk, although there is some evidence that more advanced Alzheimer’s patients might be most likely to experience brain swelling. The final CMS coverage decision must clearly specify how they will protect clinical trial participants, including guaranteeing monitoring with free brain scans.

  1. CMS should be consistent in its coverage for other medical products that are not proven to be safe or effective.

When the FDA approves medical products that are not proven to be safe or effective, we urge the CMS to require evidence of meaningful clinical benefit in well-designed clinical trials, as they are proposing to do with Aduhelm and similar Alzheimer’s drugs.

We appreciate the opportunity to provide our views and strongly encourage CMS to consider our recommendations aimed at requiring scientific evidence for important regulatory decisions.



Government Accountability Project

Government Informational Watch

Jacobs Institute of Women’s Health

National Center for Health Research

Union of Concerned Scientists