The European Medicines Agency (EMA) has reversed its stance on Biogen and Eisai’s Alzheimer’s therapy, Leqembi (lecanemab), now recommending its approval for a specific subset of patients after initially rejecting it in July 2024.
In July, the EMA’s Committee for Medicinal Products for Human Use (CHMP) issued a negative opinion on Leqembi, citing concerns over its safety and efficacy when used broadly in patients with early Alzheimer’s disease. At the time, the committee highlighted the therapy’s risk of causing amyloid-related imaging abnormalities (ARIA), which may indicate brain swelling, fluid buildup, or bleeding visible on MRI scans. They also argued that Leqembi’s effect in delaying cognitive decline was “not large enough” to offset these risks in a wider patient population.
However, following a re-examination requested by the company, the CHMP now recommends Leqembi for patients with mild cognitive impairment or mild dementia due to Alzheimer’s disease, provided they carry only one or no copies of a gene variant called ApoE4. These patients are believed to face a lower risk of developing ARIA than those with two copies of ApoE4.
The CHMP’s revised recommendation is based on new subgroup analyses that excluded data from patients with two copies of ApoE4, who are at the highest risk of ARIA. Among patients treated with Leqembi, 8.9% of those with one or no copies of ApoE4 experienced ARIA-E (brain swelling), compared to 12.6% in the broader patient group. Similarly, ARIA-H (brain bleeding) was observed in 12.9% of the restricted group, versus 16.9% of all patients. For comparison, placebo-treated patients in the restricted group experienced ARIA-E and ARIA-H at rates of 1.3% and 6.8%, respectively.
The EMA is expected to make a final decision on the marketing authorisation application of Leqembi based on the CHMP recommendation in January 2025. To mitigate risk, the EMA has said that Leqembi will be accessible through a controlled programme, allowing use only in the recommended patient group. Patients will undergo magnetic resonance imaging (MRI) scans to monitor for ARIA before starting treatment and again before the 5th, 7th, and 14th doses, with additional scans as needed if symptoms arise.
Leqembi, which targets amyloid plaques in the brain—a hallmark of Alzheimer’s thought to impair memory and cognition—received accelerated approval from the US Food and Drug Administration (FDA) in January 2023, which was converted to full approval in July 2023. Earlier this month, however, Eisai had to adjust its sales forecast for Leqembi, lowering it by $90m to $280m (¥42.5 billion) for the second half of the 2024 fiscal year. The company cited delays in US revenue as the main reason for lowering the revenue forecast.
This year has seen both praise and scrutiny of Alzheimer’s therapies. In October, the UK’s National Institute for Health and Care Excellence (NICE) recommended against the broad use of Eli Lilly’s Kisunla (donanemab), while the EMA continues to review it. Kisunla works in a similar manner to Leqembi, designed to remove amyloid plaques from the brain.
The number of people with Alzheimer’s in the eight major markets (US, France, Germany, Italy, Spain, UK, Japan, and China) is expected to grow from 21,921,200 in 2020 to 29,898,812 in 2030, as per GlobalData.
GlobalData is the parent company of Pharmaceutical Technology.
