Trial results for lecanemab in subjects with early Alzheimer's Disease were posted on ClinicalTrials.gov on 2026-03-04. The Phase 2 study (NCT01767311) showed that the lecanemab 10 mg/kg biweekly arm resulted in a mean change from baseline in ADCOMS of 0.077 at Month 12, compared to 0.113 for placebo.
Background
The study investigated lecanemab for subjects with early Alzheimer's Disease, aiming to evaluate its safety, tolerability, and efficacy.
Trial design
The study (NCT01767311) was a Phase 2, multinational, multicenter, double-blind, placebo-controlled, parallel-group study. It enrolled 856 participants with early Alzheimer's Disease. The trial used a Bayesian design with response adaptive randomization across placebo or 5 active arms of lecanemab to determine clinical efficacy and explore dose response using a composite clinical score (ADCOMS). The core study was 18 months, with lecanemab administered at 2.5 mg/kg biweekly, 5 mg/kg biweekly, 10 mg/kg biweekly, 5 mg/kg monthly, and 10 mg/kg monthly, compared to a placebo arm.
Key results
The trial evaluated the change from baseline in Alzheimer's Disease Composite Score (ADCOMS) at Month 12 across various treatment arms:
- For the Placebo group, the mean change was 0.113 (Standard Deviation: 0.012).
- For Lecanemab 2.5 mg/kg Biweekly, the mean change was 0.134 (Standard Deviation: 0.024).
- For Lecanemab 5 mg/kg Monthly, the mean change was 0.119 (Standard Deviation: 0.021).
- For Lecanemab 5 mg/kg Biweekly, the mean change was 0.116 (Standard Deviation: 0.016).
- For Lecanemab 10 mg/kg Monthly, the mean change was 0.084 (Standard Deviation: 0.011).
- For Lecanemab 10 mg/kg Biweekly, the mean change was 0.077 (Standard Deviation: 0.014).
Regarding safety, the number of participants with all Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) were:
- Placebo: 216 Participants
- Lecanemab 2.5 mg/kg Biweekly: 46 Participants
- Lecanemab 5 mg/kg Monthly: 48 Participants
- Lecanemab 5 mg/kg Biweekly: 81 Participants
- Lecanemab 10 mg/kg Monthly: 238 Participants
- Lecanemab 10 mg/kg Biweekly: 139 Participants
A key analysis reported a Posterior Probability of 63.8.
What this means
The results from this Phase 2 study suggest a dose-response trend for lecanemab in early Alzheimer's Disease, with higher doses showing lower mean changes in the ADCOMS score at Month 12. Specifically, the 10 mg/kg biweekly and 10 mg/kg monthly regimens demonstrated numerically lower ADCOMS scores compared to placebo, indicating a potential reduction in disease progression as measured by this composite clinical score. These findings contribute to the understanding of lecanemab's efficacy profile in this patient population.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT01767311, titled "A Study to Evaluate Safety, Tolerability, and Efficacy of Lecanemab in Subjects With Early Alzheimer's Disease," were posted on 2026-03-04 on clinicaltrials.gov.