공지 • Mar 21
Eisai Co., Ltd. And Biogen Inc. Present Real-World Data On Leqembi (Lecanemab-Irmb) Treatment Persistence In The United States
Eisai Co., Ltd. and Biogen Inc. announced that new real-world findings from an analysis of long-term treatment persistence and baseline characteristics among people receiving intravenous (IV) lecanemab (generic name, brand name LEQEMBI®), an anti-amyloid-ß (Aß) protofibril antibody, showed that most patients continue with ongoing lecanemab therapy after the initial 18 months of treatment. The analysis was presented at the 20th International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders (AD/PD™ 2026) in Copenhagen, Denmark, and online. In real-world clinical practice, patients with chronic diseases who stay on their treatments longer tend to experience better clinical outcomes and higher satisfaction. Ninety-four percent of patients who completed 18 months of lecanemab treatment in the Phase III Clarity AD study chose to continue maintenance treatment by enrolling in the subsequent open-label, long-term extension (OLE) study. In the OLE of the Clarity AD study, patients continue to benefit from four years of lecanemab treatment compared with the natural course of Alzheimer's disease (Alzheimer's Disease Neuroimaging Initiative: ADNI). This analysis is the first time real-world lecanemab data on treatment persistence beyond 18 months has been reported. This study was a retrospective observational analysis using the PurpleLab® CLEAR Claims database, a comprehensive dataset based on medical insurance claims across the United States and was conducted to evaluate the long-term treatment persistence of lecanemab in real-world clinical practice. The analysis population consisted of 10,763 individuals who met the requirement for continuous healthcare encounters, out of the 13,388 individuals recorded in the database who received at least one IV treatment with lecanemab between January 6, 2023 and November 30, 2025. At baseline, the mean age was 73.8 years and 56.5% were female. The most common comorbidities were dyslipidemia (42.2%) and hypertension (36.9%). The mean follow-up duration was 350.9 days. The average number of administrations was 1.7 per month, and the mean dosing interval was 16.4 days (median 14 days), which was generally consistent with the recommended every two weeks dosing. The time-dependent proportion of patients who remained on lecanemab treatment was evaluated using the Kaplan–Meier method in a subgroup of 371 patients who initiated treatment in 2023 and had 20 months of continuous follow-up, thereby enabling assessment of long-term treatment persistence beyond 18 months. As a result, 78.4% of individuals continued lecanemab treatment at 18 months, 71.7% at 20 months, and 67.3% at 24 months. Of the 78.4% of patients who remained on lecanemab at 18 months, the majority of them continued treatment during the maintenance period beyond 18 months, confirming a high rate of treatment persistence with lecanemab in real-world clinical practice. The patient characteristics and dosing patterns observed in this claims-based analysis were generally similar to those reported in the Clarity AD study. Furthermore, the relatively high treatment adherence observed among individuals suggests that potential delays due to MRI monitoring requirements, adverse events, and other factors did not substantially affect lecanemab dosing. Eisai serves as the lead for lecanemab's development and regulatory submissions globally with Eisai and Biogen co-commercializing and co-promoting the product and Eisai having final decision-making authority. Lecanemab is the result of a strategic research alliance between Eisai and BioArctic. It is a humanized immunoglobulin gamma (IgG1) monoclonal antibody directed against aggregated soluble (protofibril) and insoluble forms of amyloid-beta (Aß). Lecanemab has been approved in 53 countries and regions including Japan, the United States, China, Europe, South Korea, Taiwan, and Saudi Arabia, and is under regulatory review in 6 countries. Following the initial phase with treatment every two weeks for 18 months, intravenous (IV) maintenance dosing with treatment every four weeks was approved in 7 countries including the U.S., China, the UK, and others, and applications have been filed in 10 countries and regions. The U.S. FDA approved Eisai's Biologics License Application (BLA) for subcutaneous maintenance dosing with LEQEMBI IQLIK in August 2025. A Supplemental Biologics License Application (sBLA) for initiation treatment was accepted in January 2026. The sBLA has been granted Priority Review, with a Prescription Drug User Fee Act (PDUFA) action date of May 24, 2026. In November 2025, an application for a subcutaneous injectable formulation in Japan was submitted. In January 2026, the Biologics License Application (BLA) for the subcutaneous formulation was accepted in China. In December 2025, Lecanemab (IV) has been included in the "Commercial Insurance Innovative Drug List", recently introduced by the National Healthcare Security Administration (NHSA) of China. In the global Phase 3 placebo-controlled, double-blind, parallel-group, randomized Clarity AD core study, the mean change from baseline between the lecanemab treated group and the placebo group after 18 months was -0.45 (P=0.00005) on the primary endpoint of CDR-SB global cognitive and functional scale. Over three years of treatment, including both the core study and the OLE, data showed lecanemab demonstrated a reduction in cognitive decline—measured by CDR-SB—of 1.01 points compared to the expected decline observed in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. This benefit grew more pronounced after four years, with a reduction of 1.75 points. Similarly, when benchmarked against the expected decline in the BioFINDER* cohort, lecanemab showed a reduction of 1.40 points at three years and an even greater reduction of 2.17 points at the four years mark. Since July 2020 the Phase 3 clinical study (AHEAD 3-45) for individuals with preclinical AD, meaning they are clinically normal and have intermediate or elevated levels of amyloid in their brains, is ongoing. Since January 2022, the Tau NexGen clinical study for Dominantly Inherited AD (DIAD), that is conducted by Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU), led by Washington University School of Medicine in St. Louis, is ongoing and includes lecanemab as the backbone anti-amyloid therapy.
