Leqembi filed in Japan for mild cognitive impairment due to Alzheimer’s disease and mild AD dementia

This application is based on the results of the Phase III Clarity AD study and Phase IIb clinical study (Study 201), which demonstrated the lecanemab treatment showed a reduction of clinical decline in early AD. Prior to submitting this application, Eisai utilized the prior assessment consultation system of PMDA, with the aim of shortening the review period for lecanemab.

In the Clarity AD study, lecanemab treatment resulted in highly statistically significant results, reducing clinical decline on the global cognitive and functional scale as the primary endpoint (CDR-SB2: Clinical Dementia Rating-Sum of Boxes) as early as six months, and over time across all time points. All key secondary endpoints also showed highly statistically significant results. Especially, treatment with lecanemab showed a statistically significant reduction in amyloid plaque burden at all timepoints starting at 3 months in the amyloid PET study and statistically significantly slowed decline of activities of daily living on ADCS MCI-ADL3. The most common adverse events (>10%) in the lecanemab group were infusion reactions, ARIA-H (combined cerebral microhemorrhages, cerebral macrohemorrhages, and superficial siderosis), ARIA-E (edema/effusion), headache, and fall.

In November 2022, the results of Clarity AD study were presented at the 15th Clinical Trials on Alzheimer’s Disease (CTAD) conference and simultaneously published in the peer-reviewed medical journal the New England Journal of Medicine.