European regulators have once again expressed their support for the Alzheimer’s treatment Leqembi, developed jointly by Eisai and Biogen, paving the way for potential approval by the European Commission. This renewed endorsement follows a supplementary safety evaluation requested by the EC, which was conducted after an initial positive recommendation from the European Medicines Agency (EMA) panel in November.
The additional safety review did not alter the committee’s original favorable stance on the medication. This development marks a significant milestone for Leqembi in Europe, where approximately 22 million individuals suffer from Alzheimer’s-related disabilities or dementia across the European Economic Area’s 30 member countries.
The drug’s journey to potential European approval has been marked by several challenges. Initially, the EMA rejected Leqembi, but this decision was subsequently overturned following an appeal by the pharmaceutical companies. Such reversals are uncommon in the regulatory process, making this outcome particularly noteworthy.
Leqembi, along with its competitor Kisunla from Eli Lilly, functions by eliminating amyloid beta, a toxic protein that accumulates in the brains of Alzheimer’s patients. While both medications demonstrate modest success in slowing disease progression, they carry the risk of ARIA (amyloid-related imaging abnormalities), which can manifest as brain swelling or microbleeding.
The presence of these ARIA-related complications has led to cautious approaches from medical professionals when prescribing these medications. This concern was initially reflected in the EMA panel’s first rejection of Leqembi in July, when they determined that the drug’s cognitive decline benefits did not sufficiently outweigh its potential side effects.
However, subsequent analysis revealed that the risk of ARIA varies significantly based on genetic factors. Specifically, individuals with either no copies or a single copy of the ApoE4 gene variant showed lower risk levels, making them more suitable candidates for treatment. Conversely, patients carrying two copies of this gene variant, who typically experience earlier disease onset, face higher risks that were deemed unacceptable by regulators.
The successful appeal by Eisai and Biogen centered on this genetic risk stratification, convincing the panel that the medication’s benefits could outweigh its risks in appropriately selected patients. This nuanced understanding of genetic factors in treatment safety helped transform the drug’s regulatory prospects in Europe.
This positive recommendation represents a remarkable turnaround for Leqembi in the European market. The drug’s potential approval would provide a new treatment option for Alzheimer’s patients across the continent, though its use would likely be limited to those with favorable genetic profiles regarding ARIA risk.
The development also highlights the evolving understanding of personalized medicine in Alzheimer’s treatment, where genetic factors play a crucial role in determining treatment suitability. This approach to patient selection based on genetic markers represents a more sophisticated strategy for balancing therapeutic benefits against potential risks.
As the European Commission prepares to make its final decision, the reaffirmed positive opinion from the EMA panel suggests that Leqembi may soon become available to eligible patients throughout the European Economic Area, marking a significant advance in the treatment options available for Alzheimer’s disease in Europe.