FDA’s Approval of Biogen’s New Alzheimer’s Drug Has Huge Cost Implications for Medicare and Beneficiaries

The question of what would happen when a new, expensive prescription drug comes to market for a disease like Alzheimer’s that afflicts millions of people has loomed large in discussions over drug prices in the U.S.—and now we’re about to find out. After a nearly 20-year dry spell in new treatments for Alzheimer’s disease, the Food and Drug Administration (FDA) just approved a new Alzheimer’s medication, Aduhelm (aducanumab), developed by Biogen, with an expected annual price tag of $56,000. While the scientific community debates the evidence of the effectiveness of this new drug, the FDA’s decision raises hope for Alzheimer’s patients and their families, along with serious cost concerns for patients and payers, particularly Medicare.

Alzheimer’s disease is estimated to affect about 6 million Americans, the vast majority of whom are age 65 and older and therefore eligible for Medicare. As an intravenous infused medication administered by physicians, Aduhelm will be covered under Medicare Part B, which generally covers FDA-approved physician-administered medications that are reasonable and necessary for the individual patient. (In contrast, Medicare Part D covers retail prescription drugs.) With FDA approval in hand, attention now turns to decision-makers at the Centers for Medicare & Medicaid Services (CMS) who may opt to undertake a National Coverage Determination process that could set some limits on the conditions of Medicare coverage for Aduhelm based on the drug’s clinical effectiveness.

Medicare’s long-standing practice is to make coverage determinations without taking cost into consideration. While Medicare sets rates for hospitals and other providers, it does not set its own rates for drugs covered under Part B. Instead, Medicare reimburses providers 106% of the Average Sales Price (ASP), which is the average price to all non-federal purchasers in the U.S, inclusive of rebates. For drugs where no ASP is available, such as a new drug like Aduhelm, Medicare pays 103% of the wholesale acquisition cost (WAC) until ASP data are available. The WAC is equivalent to a list price and typically higher than ASP. Biogen has set the list price for Aduhelm at $56,000 for a year of treatment.

It is hard to know exactly how many Medicare beneficiaries will take Aduhelm, but even a conservative estimate would lead to a substantial increase in Medicare spending. In 2017, nearly 2 million Medicare beneficiaries used one or more of the currently-available Alzheimer’s treatments covered under Part D, based on our analysis of Medicare Part D claims data. If just one-quarter of these beneficiaries are prescribed Aduhelm, or 500,000 beneficiaries, and Medicare pays 103% of $56,000 in the near term, total spending for Aduhelm in one year alone would be nearly $29 billion, paid by Medicare and the patients who use this drug – an amount that far exceeds spending on any other drug covered under Medicare Part B or Part D, based on 2019 spending. To put this $29 billion amount in context, total Medicare spending for all Part B drugs was $37 billion in 2019.

If 1 million Medicare beneficiaries receive Aduhelm, which may even be on the low end of Biogen’s expectations, spending on Aduhelm alone would exceed $57 billion dollars in a single year – far surpassing spending on all other Part B-covered drugs combined. In fact, this amount is roughly the same that Medicare paid for all hospital outpatient services in 2019.

Alzheimer’s patients covered under Medicare Part B could also face high out-of-pocket costs for treatment with Aduhelm, both for the drug itself and for the cost of related medical services. For most Part B covered drugs and services, Medicare pays 80% of the cost and beneficiaries are responsible for the remaining 20%. This means beneficiaries would face about $11,500 in coinsurance for one year of Aduhelm treatment, which represents nearly 40% of the $29,650 in median annual income per Medicare beneficiary in 2019. Because Aduhelm is not a cure for Alzheimer’s disease, patients could incur these annual out-of-pocket costs over multiple years.

The majority of beneficiaries in traditional Medicare have supplemental insurance, such as Medigap, employer-sponsored retiree coverage, or Medicaid, that would cover some or all of the coinsurance. However, beneficiaries with Medigap or retiree health could see their premiums rise to account for higher plan liability associated with costs for Aduhelm. And close to 6 million Medicare beneficiaries, or 10% of all beneficiaries, are in traditional Medicare with no supplemental coverage, which means they are fully exposed to Medicare’s cost-sharing requirements and lack the financial protection of an out-of-pocket cap, unlike enrollees in Medicare Advantage plans.

The 24 million beneficiaries enrolled in Medicare Advantage plans are also responsible for cost sharing for Part B drugs, like Abuhelm, though they typically do not have supplemental insurance to help with these expenses. According to our estimates, in 2021, nearly 90% of Medicare Advantage enrollees are in plans that charge 20% coinsurance for Part B drugs provided in-network, the same as under traditional Medicare, though some plans impose coinsurance as high as 45% or 50% for Part B drugs administered by out-of-network providers. Medicare Advantage enrollees who use Aduhelm would be responsible for their share of costs until they reach the annual out-of-pocket maximum ($7,550 for in-network care and $11,300 for combined in-network and out-of-network care in 2021).

The billions of dollars in new Medicare Part B spending will likely lead to higher Part B premiums for all 56 million Part B enrollees in traditional Medicare and Medicare Advantage. Since Part B premiums are set to equal 25% of projected annual Part B expenditures, an increase in spending would lead to an increase in premiums. State and federal Medicaid spending will also rise, since Medicaid pays the Part B premium for about 12 million low-income Medicare beneficiaries with Medicaid, and covers coinsurance for 9 million of these beneficiaries who have both Medicare and full Medicaid coverage.

The introduction of a new high-priced drug could energize efforts in Congress to enact drug price legislation. Under H.R. 3, which passed the House of Representatives in the last Congress and was recently reintroduced, the HHS Secretary would have authority to negotiate prices for up to 250 drugs, drawing from the 125 drugs with the highest net spending in Medicare Part D and the 125 drugs with the highest net spending in the U.S. overall, which could include drugs covered under Part B, such as Aduhelm. Negotiated prices would be made available to enrollees in Part D plans and private insurance coverage, and to providers that administer physician-administered drugs. Other proposals under active consideration would limit annual price increases for Part B and Part D drugs and limit the financial incentives under Medicare’s existing Part B reimbursement system for physicians to administer higher-priced drugs. The Center for Medicare and Medicaid Innovation could also test models to modify Medicare payments for high-priced drugs.

At a time when federal and state policymakers are weighing several policy options to lower prescription drug prices, the approval of Aduhelm provides the latest high-profile example of the potential budgetary consequences of Medicare’s role as a price-taker in the pharmaceutical marketplace. Concerns about the impact on Medicare spending associated with Aduhelm are reminiscent of discussions that took place after the introduction of high-cost treatments for hepatitis C, though in that case, the new drugs cured the disease and were approved for a much smaller patient population. Aduhelm may represent hope for Alzheimer’s patients and their families who have waited years for new treatments to come along, but that hope is likely to come at a high cost to Medicare, beneficiaries, and taxpayers.

This work was supported in part by Arnold Ventures. We value our funders. KFF maintains full editorial control over all of its policy analysis, polling, and journalism activities.

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