The monthly maintenance regimen, which offers a more convenient frequency than the initially approved treatment schedule for patients with Alzheimer’s, could help with Leqembi’s thus far disappointing uptake and sales.
The FDA on Sunday gave the go-ahead for a monthly maintenance dosing regimen for Biogen and Eisai’s Alzheimer’s treatment Leqembi (lecanemab), potentially giving the anti-amyloid therapy a much-needed sales boost.
Leqembi is indicated as an intravenous infusion for patients with mild Alzheimer’s disease and is recommended as an intervention for those with mild dementia or mild cognitive impairment. For the first 18 months, patients are dosed with Leqebi every two weeks, after which they may be transitioned to the now-approved maintenance schedule of 10 mg/kg every four weeks.
As per the companies’ press announcement of the approval, maintenance treatment with Leqembi is important because “Alzheimer’s disease progression does not stop after plaque clearance.”
Ongoing treatment can also prolong the benefits of treatment and keep disease progression at bay, the partners continued, pointing to Phase II evidence showing that patients who discontinued Leqembi experienced a “reaccumulation” not only of amyloid plaques but also of other disease biomarkers in the cerebrospinal fluid. In these patients, clinical rate of decline also reverted to placebo levels after stopping Leqembi.
The approval of the monthly maintenance regimen was based on modeling findings using data from a Phase II study and its long-term extension, as well as from the Phase III Clarity AD trial. Taken together, the models suggested that transitioning to a once-monthly maintenance schedule effectively sustains the clinical and biomarker benefits of treatment.
Additionally, a monthly dosing schedule for Leqembi “may be easier for patients and care partners to continue treatment,” potentially helping with the drug’s uptake, according to Eisai’s press announcement.
Sales figures for Leqembi have so far been underwhelming. In November 2024, the Japanese pharma announced a downward adjustment to its Leqembi sales forecast, with fiscal year 2024 projection dropping to $280 million, as opposed to its previous guidance of approximately $370 million.
Earlier this month, at the 2025 J.P. Morgan Healthcare Conference, Biogen took a hit to its share price after company executives reiterated their commitment to Leqembi—and to the Alzheimer’s space more broadly—amid growing investor concerns regarding the slow rollout of the drug. At the time, analysts at BMO Capital Markets pointed to certain “struggles” with Leqembi uptake, including reimbursement barriers and the need to make providers aware of proper treatment.
Aside from the tepid market reaction, Leqembi also faces concerns about its efficacy and safety. In July 2024, the European Union’s health regulatory agency issued a negative opinion for Leqembi, noting that its benefit of slowing cognitive decline “does not counterbalance the risk of serious side events,” particularly the “frequent occurrence” of amyloid-related imaging abnormalities. The agency a few months later issued a positive opinion of the drug after Eisai asked for a re-examination of the negative opinion.
