High Praise, Condemnation for CMS Aduhelm Coverage Plan

Kerry Dooley Young

February 16, 2022

Medicare has received a key endorsement of its plan to restrict payment for the controversial Alzheimer's disease (AD) drug aducanumab (Aduhelm) — but also drew pleas from other groups for more generous reimbursement of the drug, as well as expected similar medications currently in development.

The Centers for Medicare & Medicaid Services (CMS) received more than 9900 comments on its plan, according to the current tally posted on its website. However, it is unclear when the final count will be available.

CMS intends to limit federal payment for monoclonal antibodies that target amyloid to clinical trials. Among supporters of this approach is the influential Medicare Payment Advisory Commission (MedPAC), an expert panel that helps Congress and CMS manage the federal health program.

Opponents of the CMS plan include several pharmaceutical companies. Patient and consumer groups, individuals, and lawmakers had mixed views.

CMS officials will weigh the feedback provided in the comments when setting a final coverage policy for aducanumab. It is expected the agency's final decision will be announced on April 11.

Ongoing Debate

The comments submitted to CMS reflect ongoing debate about whether the evidence proves aducanumab provides significant clinical benefit.

As reported by Medscape Medical News, the FDA's unusual approach for clearing the drug for US sales triggered a review of its management of the accelerated approval process by the Office of Inspector General for the Department of Health and Human Services (HHS-OIG).

The FDA granted an accelerated approval for aducanumab in June based on evidence that the drug clears amyloid in the brain. However, it is unclear whether clearing the protein from the brain results in clinical benefit.

Usually, accelerated approvals precede the completion of phase 3 drug trials, with the FDA allowing early access to a medicine while awaiting confirmatory trials.

In the case of aducanumab, results of the phase 3 confirmatory trials ENGAGE and EMERGE were available at the time of FDA approval. However, interpretation of the findings is controversial.

Biogen contends that the amyloid-clearing effect of the higher dose of aducanumab shown in EMERGE indicates the drug has clinical potential. However, others argue that amyloid clearance does not indicate clinical benefit.

Limiting Medicare coverage of aducanumab for treatment of AD means "the progression of disease, for nearly all beneficiaries, would continue unabated," Biogen wrote in its comment to CMS last week.

Conflicting Data

Supporters of the CMS plan have a different view of the trial data. They note the failure of aducanumab in the companion ENGAGE trial, while also questioning the magnitude of benefit suggested by even the most positive data cited for the drug in the EMERGE trial.

Both studies used the Clinical Dementia Rating-Sum of Boxes (CDR-SB) score, an 18-point scale measuring cognition and function.

In his comment to CMS, MedPAC chairman Michael E. Chernew, PhD, noted the change in CDR-SB score of 0.39 in EMERGE's high-dose aducanumab group. CMS has described this as being "less than the 1 to 2 point change that has been suggested as a minimal clinically important difference," Chernew wrote.

MedPAC does not normally comment on Medicare coverage decisions, but did so in this case because of its significance and because of the potential fiscal implications, he noted.

"Though there is only limited, conflicting data on Aduhelm's clinical effectiveness, Medicare would pay a high price for the product," Chernew wrote, pointing out the $28,200 annual US price of the drug.

MedPAC thus endorsed the coverage-with-evidence-development (CED) pathway. Under this approach, Medicare would pay for these drugs when used in clinical trials that meet certain criteria.

Legal Challenge?

In its comment to CMS, Biogen questioned the agency's legal grounds for limiting coverage of aducanumab. A mandate on clinical trials as part of the CED proposal "runs afoul of the Administrative Procedure Act's prohibition against arbitrary and capricious agency action," Biogen said.

The drug company argued that its own planned follow-on studies would provide the kind of data Medicare officials want to see. It also argued for greater use of observational data, including real-world evidence, and of information from Medicare claims.

Roche's Genentech, which is also developing anti-amyloid drugs for AD, echoed some of Biogen's concerns about the aducanumab plan.

CMS' CED plan would be "unnecessarily restrictive and discouraging for patients living with this destructive disease," David Burt, executive director for federal government affairs at Genentech, wrote in a comment to CMS.

CMS should clarify that the CED requirement would not apply to cases of FDA-approved anti-amyloid therapies that have demonstrated "clinically meaningful improvement," Burt added. He noted there are phase 3 trials of drugs in this class that could soon produce data.

CMS should "fully consider the broad ramifications and significant unintended consequences of prematurely placing unduly severe restrictions on the entire class of anti-amyloid monoclonal antibodies," Burt wrote.

Healthcare Inequity

In its comment to CMS, Biogen also noted the Medicare proposal would "compound the already pervasive inequities in access to treatment and will ultimately prove highly detrimental to health equity."

There are already concerns about the access of Black and Latinx patients to clinical trials. The planned CED approach would tightly restrict access to aducanumab, as well as expected follow-ons in the amyloid-directed monoclonal antibody (mAb) drug class, the company said.

"Many of the trial sites for Aduhelm, as well as for other amyloid-directed [monoclonal antibodies] are not hospital-based outpatient settings, but include infusion centers, private practices, and medical research centers," Biogen wrote.

Patient groups such as UsAgainstAlzheimer's told CMS the CED approach would worsen disparities, despite the aim of Medicare officials to increase participation of Black and Latinx patients in future testing.

"CMS will be hard-pressed to achieve diversity if such hospitals are the only locations where Medicare beneficiaries are able to access mAbs," USAgainstAlzheimer's wrote in a February 10 comment.

In contrast, the nonprofit National Center for Health Research (NCHR) praised CMS for what it described as an effort to address a lack of representation of Black and Latinx patients in earlier aducanumab research.

However, the NCHR also suggested CMS revise its plan to mandate that clinical trials include patients who are representative of the national population diagnosed with AD.

"Rather than being concerned about the percentage of patients in specific racial and ethnic groups, we propose that CMS include sufficient numbers of patients in different racial, ethnic, and age groups to ensure that there is enough statistical power for subgroup analyses to determine safety and efficacy for each of the major demographic groups," the NCHR wrote.

Patient Health, Medicare at Risk

On February 8, a group of House Republican lawmakers asked CMS to reverse its stance. In a publicly released letter , Rep. Cathy McMorris Rodgers of Washington state, the ranking Republican on the House Energy and Commerce Committee, and colleagues urged broader coverage of aducanumab.

In the letter, the group emphasized the idea of aducanumab as a potential treatment for patients with Down syndrome who are at-risk for AD.

"The link between Down Syndrome and AD is still being researched by scientists," Rodgers and colleagues wrote.

"However, there appears to be a correlation between the additional 21st chromosome present in people with Down Syndrome and the chromosome's gene that makes amyloid precursor proteins and can cause a build-up of the beta-amyloid plaques common amongst those with AD," they add.

On the other hand, CMS garnered earlier support from influential Democrats. On January 13, House Energy and Commerce Chairman Frank Pallone Jr (D-NJ) and House Oversight and Reform Chairwoman Carolyn B. Maloney (D-NY) released a letter praising CMS for its plan for covering aducanumab.

In addition to the HHS-OIG review of the FDA's approval of the drug, the two House committees are in the midst of their own investigation of the agency's decision to clear the drug.

"Any broader coverage determination before there is clarity on Aduhelm's approval process and findings from the myriad ongoing investigations may put the health of millions of Alzheimer's patients on the line and the financial stability of the nation's health insurance program for American seniors at risk," Pallone and Maloney wrote.

Kerry Dooley Young is a freelance journalist based in Miami Beach. She is the core topic leader on patient safety issues for the Association of Health Care Journalists. Young earlier covered health policy and the federal budget for Congressional Quarterly/CQ Roll Call and the pharmaceutical industry and the Food and Drug Administration for Bloomberg.  Follow her on Twitter @kdooleyyoung.

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