Eisai Co. and its partners have received backing from the European Union regulator for their Alzheimer's drug, Leqembi, marking a significant reversal of a previously negative opinion. The European Medicines Agency’s (EMA) drug advisory panel announced on Thursday that a re-examination of their initial decision indicated that the benefits of Leqembi outweigh the risks, but only in a restricted pool of patients.
Restriction Based on ApoE4 Gene Variant
The EMA panel specified that Leqembi should be limited to patients with one or no copy of the ApoE4 gene variant. This genetic variant is associated with a higher risk of Alzheimer’s disease, and individuals with two copies of ApoE4 are more prone to experiencing brain swelling and bleeding when taking the drug. Researchers estimate that approximately one in 50 people in the US have two copies of this variant. In the final-stage patient trial of the drug, about 15% of patients had two copies of the ApoE4 gene, while more than half had one copy.
Impact on Companies and Market
This decision represents a notable victory for Eisai and its partners, Biogen Inc. and Stockholm-based BioArctic AB, which holds the commercialization rights for Leqembi in the Nordic region. Following the announcement, Biogen’s shares initially rose by 6.1%, while Eisai’s American depositary receipts increased by as much as 14% before retracting slightly.
Statements from Biogen
Priya Singhal, Biogen’s head of development, stated that the decision is “a significant step forward in the fight against Alzheimer’s disease,” emphasizing that approval in Europe will benefit millions of patients.
Previous Concerns and Controlled Access
Previously, in July, Europe’s advisory panel had recommended against granting market authorization for Leqembi, citing that the risks, such as brain bleeding, outweighed the benefits. The EMA has indicated that the use of Leqembi in Europe will involve controlled access programs to ensure that only recommended patients receive the drug.
Global Approvals and Market Potential
Leqembi has already secured approval in several countries, including Japan, China, and the US. However, its launch has been slowed by uncertainties related to insurance coverage and complex safety-monitoring requirements. Eisai recently adjusted its forecast for Leqembi sales. According to Jefferies analyst Michael Yee, Europe could account for up to 30% of Leqembi’s worldwide peak sales.
Mechanism of Action and Disease Burden
Leqembi has demonstrated the ability to slow the progression of Alzheimer’s disease, a debilitating condition affecting approximately 6 million Americans. The drug functions by reducing amyloid levels in the brains of patients in the early stages of the disease. Eli Lilly & Co. is also developing a similar drug, Kisunla.
