Leqembi, an Alzheimer's drug developed by Biogen (BIIB.US) and Eisai (ESALF.US), has been approved for sale in the UK.

Biogen (BIIB.US) and its Japanese partner Eisai (ESALF.US) announced on Thursday that its breakthrough Alzheimer’s drug Leqembi (lecanemab) has been granted a marketing authorization in the UK, making the UK the first European country to approve the drug. The approval was primarily based on the 3-year Clarity AD trial data from Eisai, which showed statistical significance for both primary and all key secondary endpoints.

The drug targets the underlying cause of Alzheimer’s disease. Lecanemab is a humanized monoclonal antibody to IgG1, which is claimed to be the only approved Alzheimer’s drug that can slow the progression of the disease and reduce cognitive and functional decline.

In the UK, lecanemab is indicated for the treatment of mild cognitive impairment and mild dementia due to Alzheimer’s disease in adults who are ApoEε4 heterozygotes or non-carriers.

In January 2024, China approved Leqembi as a treatment for mild cognitive impairment and mild dementia due to Alzheimer’s disease, making it the third country after the US and Japan to approve the drug.

Eisai is the main developer of the drug, and Biogen is assisting with commercialization. The two companies will co-promote the drug in the UK, with Eisai acting as the marketing authorization holder.

Biogen reported its second-quarter earnings in early this month and raised its full-year earnings forecast. The second-quarter report showed that the sales of Leqembi, an Alzheimer’s drug developed in collaboration with Eisai, were around $40mn in the second quarter, much higher than the $19mn in the first quarter. The company is seeking to boost the sales of Leqembi as its multiple sclerosis drug sales are declining.

The European Medicines Agency previously rejected the drug, which was a setback for the two companies. In July, the US regulator approved a competing Alzheimer’s drug from Lilly.