For Healthcare Professionals

A Study to Confirm Safety and Efficacy of Lecanemab in Participants With Early Alzheimer's Disease


About the study

This study will be conducted to evaluate the efficacy of lecanemab in participants with early Alzheimer's disease (EAD) by determining the superiority of lecanemab compared with placebo on the change from baseline in the Clinical Dementia Rating-Sum of Boxes (CDR-SB) at 18 months of treatment in the Core Study. This study will also evaluate the long-term safety and tolerability of lecanemab in participants with EAD in the Extension Phase and whether the long-term effects of lecanemab as measured by the CDR-SB at the end of the Core Study is maintained over time in the Extension Phase.

Who can take part

You may be eligible to participate in the study if you meet the following criteria:


  1. Participants who have completed the Core Study (except de novo participants)
  2. Must continue to have a study partner who is willing and able to provide follow-up information on the participant throughout the course of the Extension Phase
  3. Provide written informed consent for the Extension Phase. If a participant lacks capacity to consent in the investigator's opinion, the participant's assent should be obtained, if required and in accordance with local laws, regulations and customs, plus the written informed consent of a legal representative should be obtained (capacity to consent and definition of legal representative should be determined in accordance with applicable local laws and regulations). In countries where local laws, regulations, and customs do not permit participants who lack capacity to consent to participate in this study (example, Germany and Spain), they will not be enrolled
  4. Participants entering the subcutaneous (vial) substudy at Extension Phase Week 1, must be willing to participate, or continue participating in the amyloid positron emission tomography (PET) substudy. All participants must have an amyloid PET scan within 4 weeks before starting subcutaneous BAN2401.
  5. Participants enrolling into the subcutaneous autoinjector substudy must have had at least 6 months exposure to BAN2401 10 mg/kg intravenously (IV) biweekly or BAN2401 720 mg subcutaneously (SC) weekly.


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    Study Locations

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    How to Apply

    Contact the study center to learn if this study is a good match for you.
    Phone iconCall 1-888-274-2378Email iconEmail Study Center

    Study’s details


    Early Alzheimer's Disease




    Phase 3

    Participants needed


    Est. Completion Date

    Sep 2027

    Treatment type



    Eisai Inc. identifier


    Study number


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