Lecanemab is an Aβ protofibril antibody, which is approved in the US for the treatment of Alzheimer’s disease and sold under the brand name LEQEMBI


Eisai-Biogen’s AD drug Lecanemab gets priority review in Japan. (Credit: Milad Fakurian on Unsplash)

Eisai and Biogen have secured priority review status for their Alzheimer’s drug lecanemab from the Japanese Ministry of Health, Labour and Welfare (MHLW).

The drug is approved in the US for the treatment of Alzheimer’s disease and is sold under the brand name LEQEMBI.

Lecanemab is an anti-amyloid-β (Aβ) protofibril antibody. It is directed against aggregated soluble (protofibril) as well as insoluble forms of amyloid-beta (Aβ).

Japan-based Eisai filed an application for the manufacturing and marketing approval for the drug with the Japanese Pharmaceuticals and Medical Devices Agency (PMDA) on 16 January 2023.

The application was based on findings from a phase 2b clinical investigation and the phase 3 Clarity AD study, which revealed that lecanemab therapy showed a reduction in clinical decline in early AD.

According to Biogen, the toxic, protofibrils that are thought to be responsible for the neurotoxicity in AD are preferentially bound and eliminated by lecanemab.

In the Clarity AD study, lecanemab met the primary endpoint and all key secondary endpoints with highly statistically significant results.

The findings of the Clarity AD trial were presented at the Clinical Trials on Alzheimer’s Disease (CTAD) conference in November 2022 and published simultaneously in the peer-reviewed New England Journal of Medicine.

The US Food and Drug Administration (FDA) granted lecanemab accelerated approval as a therapy for AD earlier this month.

A marketing authorisation application (MAA) was submitted by Eisai to the European Medicines Agency (EMA) earlier this month, which was accepted by the regulator on 26 January.

Additionally, the Japanese pharmaceutical firm started submitting data for a BLA in December 2022 to the National Medical Products Administration (NMPA) in China.

Lecanemab’s development and regulatory submissions are overseen by Eisai, which also has the final decision-making power. The company alongside Biogen is jointly marketing and promoting the drug.