Pink Sheet: Medicare Spending Forecast For Leqembi Reflects CMS Angst About Alzheimer’s Drug Costs

by Cathy Kelly, April 15, 2025

The agency’s projection that Medicare will spend $3.5bn on Leqembi in 2025 is nearly three times the level of sales that marketer Eisai is expecting for the drug in North and South America combined in its fiscal year 2026.

The Centers for Medicare and Medicaid Services appear to be anticipating much stronger near-term uptake of Eisai Co., Ltd. and Biogen, Inc.’s Leqembi (lecanemab-irmb) for Alzheimer’s disease than the companies do, based on a forecast recently disclosed by the agency.

CMS expects Medicare Part B spending on Leqembi will reach approximately $3.5bn in 2025 across the fee-for-service and Medicare Advantage programs, according to an agency spokesperson. For perspective, overall Medicare spending on Part B drugs reached $43bn in 2021.

The prediction assumes expenditures of $1.5bn in the fee-for-service program and roughly $2bn in Medicare Advantage. However, the spokesperson noted, “the actual net payments to MA plans will be determined after bid submissions and could vary substantially based on the bidding behavior.”

The $3.5bn would follow $550m in Leqembi spending in the fee-for-service program alone in 2024, according to CMS.

The spokesperson said CMS focused only on FFS spending in 2024 because “the Leqembi approval happened after the 2024 Medicare Advantage rate development, [and] federal spending for MA is not directly impacted by Leqembi costs” this year. Leqembi obtained a full approval from the US Food and Drug Administration in July 2023. (Also see “Leqembi Safety Is Focus Of Three Postmarketing Requirements From US FDA” – Pink Sheet, 10 Jul, 2023.)

CMS actuaries provided a short-hand version of the estimates during the question-and-answer portion of a 22 February call with industry actuaries preparing bids for the upcoming Medicare benefit year.

“The estimated Leqembi spending is $1.67 [per member per month] for CY 2024 and $4.67 PMPM for CY 2025” in the fee-for-service program, the agency said. A CMS spokesperson provided the corresponding dollar spending figures in response to an inquiry from the Pink Sheet.

CMS’ $3.5bn estimate for 2025 implies that up to 130,000 patients would be treated that year, while the number expected to be treated to reach $550m in 2024 spending could be around 20,000.

The agency would not explain whether it included costs beyond the drug’s price in its calculations. Leqembi has an average list price of $26,500, but CMS may also be considering the cost of administration, diagnostic testing and treating potential adverse events.

Nevertheless, the CMS forecast for near-term uptake of the drug is significantly higher than Eisai’s recent projections. The $3.5bn assumption for 2025 is nearly three times the $1.3bn in revenue that Eisai expects to book for all Leqembi sales in North and South America in its fiscal year 2026 (ending 31 March 2027), according to a company report released 8 March.

And during its third quarter earnings presentation on 6 February, Eisai said it hopes to treat 10,000 in patients in the US this year, though it expects reaching that goal will be a “challenge.”

Just 2,000 patients had received the drug as of January because uptake has been hampered by the lack of treatment infrastructure for diagnosing, treating and monitoring patients, the company said. Eisai maintains the trajectory of patients could ramp up quickly in the coming years and projects Leqembi could treat 100,000 patients in the US in 2026.

Projections Met With Skepticism

Neither Eisai nor CMS would comment on the disparity between the company’s recent forecasts and the agency’s projection.

“We cannot speculate on CMS’s assessments,” a company spokesperson told the Pink Sheet.

“Eisai has not spoken with representatives at CMS about this matter as it would not be appropriate.”

“We aim for accuracy in our projections and transparently share that information via our earnings reports and other public communications,” the company added.

Alzheimer’s patient and research advocates are skeptical that the CMS predictions will be realized.

“There is no evidence the health care systems and payers have the imaging and diagnostic capacity to treat over 100,000 patients in 2025,” Global Alzheimer’s Platform Foundation President John Dwyer told the Pink Sheet.

“My guess is no one could prudently forecast more than 20,000 patients in 2025 if current trends hold and that is probably optimistic based on what we are seeing and hearing,” Dwyer said. “The American neurology health system is nearly paralyzed.”

The discrepancy is “puzzling,” agreed Alliance for Aging Research President and CEO Sue Peschin.

“The number of Medicare beneficiaries who receive Leqembi would need to grow exponentially this year and next in order for CMS’ forecast to be accurate,” she said. “Given Medicare’s complex coverage policy for disease-modifying Alzheimer’s therapies, that seems unlikely.”

CMS requires patients to be enrolled in a registry to obtain Medicare reimbursement, which “makes it more difficult for people who live in rural areas, those that belong to underserved groups, and those without access to transportation” to get access to Leqembi, Peschin said.

“I’m not sure what CMS is trying to accomplish at this point with these overblown estimates,” she said.

Concern With Medicare Spending On AD Drugs A Familiar Theme

If nothing else, the CMS predictions reiterate the agency’s concern with the potential cost to Medicare of Alzheimer’s drugs, which is reflected in two recent and noteworthy steps to blunt their impact on the program.

The concern is widely believed to have prompted the current   coverage restrictions for Leqembi and other anti-amyloid monoclonal antibody drugs for Alzheimer’s, though CMS maintains it does not take cost into account when developing the policies.

Under a Medicare national coverage determination that applies to the class, drugs with a traditional approval may be covered only when patients are enrolled in a registry. Coverage for drugs with accelerated approval are conditioned on patient participation in a clinical trial. (Also see “Eisai Plots A Meticulous Path To Medicare Coverage For Lecanemab” – Pink Sheet, 2 Dec, 2022.)

Even before the NCD was finalized, CMS announced one of the biggest year-to-year increases in dollar terms in the monthly cost of Medicare Part B premiums, due in large part to the threat of ballooning expenditures on Biogen’s now-discontinued Alzheimer’s drug Aduhelm (aducanumab-avwa). (Also see “Medicare Premium Hike Will Help Build ‘Contingency Fund’ For Alzheimer’s Drugs” – Pink Sheet, 14 Nov, 2021.)

The increase was lowered months later after Biogen cut the drug’s price in half and CMS restricted coverage with the NCD. (Also see “Of Price And Premiums: Medicare Has Put Alzheimer’s Drug Sponsors On Notice” – Pink Sheet, 31 May, 2022.)

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