The European Medicines Agency (EMA) has granted approval for Leqembi, a drug designed to slow the progression of early-stage Alzheimer's disease. This decision follows an initial rejection due to concerns about the risk of serious side effects, including brain bleeding. The approval is a significant step forward in Alzheimer's treatment, offering a new option for patients in the early stages of the disease.
Leqembi, developed by Eisai and Biogen, is administered intravenously every two weeks. Clinical trials have demonstrated its ability to reduce amyloid plaques, which are thought to contribute to the cognitive decline associated with Alzheimer's disease. The EMA's decision is based on a re-evaluation of the drug's benefits and risks, specifically in a restricted patient population.
The EMA has recommended Leqembi for patients who have not reached an advanced stage of Alzheimer's disease. The agency emphasized that the benefits of the treatment outweigh the risks in this specific group. A key factor in the approval was the consideration of patients with varying copies of the ApoE4 gene, a known risk factor for Alzheimer's. The treatment is approved for patients with only one or no copy of the ApoE4 gene, as those with two copies are at higher risk of brain hemorrhage, a potential side effect of Leqembi.
Availability and Monitoring
Leqembi will be made available through a controlled program to ensure it is used only in appropriate patients. This approach aims to mitigate the risks associated with the drug, particularly the potential for ARIA (Amyloid-Related Imaging Abnormalities), which can manifest as brain edema (ARIA-E) or hemorrhage (ARIA-H). The EMA's review included subgroup analyses that excluded data from patients with two copies of the ApoE4 gene, who are at the highest risk of ARIA.
Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access, stated, "Licensing medicines which meet acceptable standards of safety, quality and efficacy is a key priority for us. We’re assured that, together with the conditions of the licence approval, the appropriate regulatory standards for this medicine have been met. As with all medical products, we will keep its safety under close review, and with a controlled post-authorisation safety study to be undertaken, we will ensure that the benefit risk of lecanemab in clinical use is closely followed up."
Expert Perspectives
Mercè Rovira, a neurologist and clinical director at Ace Alzheimer Center in Barcelona, views the approval as a positive development. "Europe needed this news. It needed to know that we had the possibility to treat patients, we needed to know that all the research in this field would continue," she told the Science Media Center (SMC).
Hilary Evans-Newton, chief executive of Alzheimer's Research UK, also sees the partial approval as positive: "Although not a cure, lecanemab is an important step forward," she also told SMC. "This progress, however modest, is a major advance in the way Alzheimer's disease is treated."
Global Context
Leqembi has already been approved for use in the United States (since January 2023), Japan, China, and the UK (where it is marketed as Lecanemab). The drug's availability in multiple regions underscores the global effort to address the growing burden of Alzheimer's disease, which affects millions worldwide.
