Leqembi (lecanemab) is the first medicine that slows progression of early Alzheimer’s disease to be authorized in the European Union- Eisai + Biogen

Eisai Co., Ltd.  and Biogen Inc.  announced that the European Commission (EC) has granted the amyloid-beta (Aβ) monoclonal antibody Leqembi (lecanemab) Marketing Authorization (MA) in the European Union (EU). This makes the medicine the first therapy that targets an underlying cause of Alzheimer’s disease (AD) to be granted a MA in the EU. Lecanemab is indicated for the treatment of adult patients with a clinical diagnosis of mild cognitive impairment (MCI) and mild dementia due to AD (early AD) who are apolipoprotein E ε4 (ApoE ε4) non-carriers or heterozygotes with confirmed amyloid pathology. The lecanemab MA applies to all 27 EU Member States as well as Iceland, Liechtenstein and Norway.

The EC’s authorization was primarily based on Phase III data from Eisai’s global Clarity AD clinical trial, in which it met its primary endpoint and all key secondary endpoints with statistically significant results. Clarity AD was a Phase III global, placebo-controlled, double-blind, parallel-group, randomized study in 1,795 patients with early AD (MCI or mild dementia due to AD, with confirmed presence of amyloid pathology). Of the total number of patients randomized, 1,521 were in the EU indicated population (ApoE ε4 non-carriers or heterozygotes). The treatment group was administered lecanemab 10 mg/kg bi-weekly, with participants allocated in a 1:1 ratio to receive either placebo or lecanemab for 18 months. 

Lecanemab is the only approved Aβ monoclonal antibody that preferentially binds and clears toxic protofibrils (soluble Aβ aggregates), in addition to targeting and reducing Aβ plaques (insoluble Aβ aggregates).  Protofibrils are a key toxic form of Aβ that accumulate in the brain and cause neuronal injury. 

MCI due to AD and AD dementia currently affects an estimated 15.2 million and 6.9 million people in Europe, respectively. AD progresses in stages that increase in severity over time, and each stage of the disease presents different challenges for those living with AD and their care partners. There is a significant unmet need for new treatment options that slow down the progression of AD from its early stage and reduce the overall burden on people affected by AD and society.

See  citation- Van Dyck CH, Swanson CJ, Aisen P et al. Lecanemab in Early Alzheimer’s Disease. N Engl J Med 2023, 388: 9 DOI: 10. 1056/NEJMoa2212948