# CLARITY AD

Source: https://onco.cc/trials/da-trial-clarity-ad/  
OnCo record `da-trial-clarity-ad` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CLARITY AD tested lecanemab in early Alzheimer’s disease. It is the main efficacy trial behind the US traditional approval.

## Summary

A randomised, placebo-controlled phase 3 study in early symptomatic Alzheimer’s disease with confirmed amyloid. Primary clinical scale results favoured lecanemab. ARIA occurred, more often in ApoE ε4 carriers. This atlas does not treat a mean scale change as a promise for an individual.

## Fields

- Kind: Trial
- Status: completed
- Last checked: 2026-09-21
- Tags: dementia-atlas
- Registry id: NCT03887455
- Phase: 3
- Setting: Early Alzheimer’s disease
- Sponsor: Eisai
- Enrolled: 1795
- Result: The trial met its primary clinical endpoint versus placebo. ARIA was the principal safety theme. See the FDA approval communication for the regulator’s reading.
- Outcomes: Clinical scale change (primary): Lecanemab vs Placebo

## Sources

- ClinicalTrials.gov NCT03887455: https://clinicaltrials.gov/study/NCT03887455
- FDA traditional approval: https://www.fda.gov/news-events/press-announcements/fda-converts-novel-alzheimers-disease-treatment-traditional-approval

## Connected records

- diagnoses: [Alzheimer’s disease](https://onco.cc/diagnoses/alzheimers-disease/)
- drugs: [Lecanemab](https://onco.cc/drugs/da-lecanemab/)
- companies: [Biogen](https://onco.cc/companies/da-biogen/), [Eisai](https://onco.cc/companies/da-eisai/)
- key papers: [Lecanemab in Early Alzheimer’s Disease (CLARITY AD)](https://onco.cc/key-papers/da-paper-clarity-ad/)

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