Long‐term safety and efficacy of lecanemab in early Alzheimer's disease: Results from the clarity AD open‐label extension study

This research evaluated the long-term efficacy, safety, and HRQoL results from an ongoing extension of the phase 3 Clarity AD, which included open-label lecanemab treatment for up to 36 months. Overall, the results show participants continue to accrue a lecanemab treatment benefit up to 36 months and highlight the importance of continued long-term lecanemab treatment. Results presented in our paper demonstrate that lecanemab continued suppression of amyloid plaque levels and significantly slowed clinical decline on multiple measures of cognition, function, and quality of life in early AD at 18 months and continued for 36 months to date. No new safety signals were observed with continued lecanemab treatment. After the first 6 months, ARIA rates were low and similar to ARIA rates on placebo, with no association between ARIA occurrence and accelerated long-term clinical progression. Taken together with existing data, these results provide a clear rationale and a demonstration of the disease modification effects of long-term lecanemab therapy.