The fight against Alzheimer's disease takes a significant step forward with a groundbreaking treatment option.
LEQEMBI®, a humanized anti-soluble aggregated amyloid-beta (Aβ) monoclonal antibody, has been approved for once-every-four-weeks intravenous (IV) maintenance dosing in the United Kingdom. This approval is a joint effort by Eisai Co., Ltd. and Biogen Inc., marking a crucial milestone in the journey to combat this relentless disease.
Alzheimer's disease (AD) is a progressive condition affecting the brain, characterized by the formation of protein deposits called plaques, made of amyloid-beta aggregates, and neurofibrillary tangles composed of tau protein. It's a disease that robs individuals of their memories and identities, impacting not just patients but also their loved ones. The underlying neurotoxic process starts before plaque accumulation and persists even after their removal, making it a complex and challenging condition to treat.
But here's where LEQEMBI® steps in: it's the only treatment that tackles AD in two ways. It targets both amyloid plaques and protofibrils, which are believed to be the most toxic Aβ species contributing to brain damage in AD. By reducing protofibrils, LEQEMBI® may potentially slow down the progression of the disease and help patients maintain their cognitive abilities for longer.
The approval for IV maintenance dosing comes after the initial 18-month treatment regimen, allowing patients to transition to a less frequent dosing schedule. This is crucial, as continuing maintenance treatment is essential to slow AD's progression and maintain therapeutic benefits. The reaccumulation of AD biomarkers and the return to the placebo rate of decline after therapy cessation emphasize the need for ongoing treatment.
In the UK, the number of people living with dementia is estimated at 982,000, with AD being the cause in 60-70% of cases. These numbers are expected to rise with an aging population, making the need for effective treatments even more urgent.
Eisai and Biogen's collaboration on the development and commercialization of AD treatments since 2014 has been pivotal. Eisai leads the global development and regulatory submissions, while both companies co-commercialize and co-promote the product, with Eisai having the final decision-making authority.
Controversy arises when discussing the role of apolipoprotein E (ApoE). People with one or no copies of the ApoE ε4 gene are less likely to experience ARIA (a type of adverse event) than those with two copies. This genetic factor adds a layer of complexity to the treatment landscape.
The development of LEQEMBI® is a result of a strategic research alliance between Eisai and BioArctic, with approvals in 51 countries and ongoing regulatory reviews in 9 others. The Phase 3 Clarity AD clinical trial demonstrated its efficacy, meeting primary and key secondary endpoints. The U.S. FDA approved subcutaneous maintenance dosing in August 2025, and a rolling application for subcutaneous initiation dosing was initiated in September 2025.
Ongoing clinical studies, such as AHEAD 3-45 for individuals with preclinical AD and the Tau NexGen study for Dominantly Inherited AD, further reinforce the commitment to finding effective treatments. These studies are conducted in collaboration with various institutions, showcasing a united front against AD.
As we celebrate this approval, it's essential to acknowledge the challenges and controversies in the field of Alzheimer's research. What are your thoughts on the role of ApoE in AD treatment? Do you think LEQEMBI®'s dual approach is a game-changer? Share your insights and let's continue the conversation on this critical topic.
