for people ages 50-85 (full criteria)
study started
estimated completion



The name of this trial is MissionAD2. This 24-month treatment, multicenter, double-blind, placebo-controlled, parallel group, Phase 3 study in participants with Early Alzheimer's Disease (EAD) including mild cognitive impairment (MCI) due to Alzheimer's Disease (AD)/Prodromal AD and the early stages of mild AD will be conducted to evaluate the efficacy and safety of elenbecestat (proposed international nonproprietary name [pINN]) (E2609).

Official Title

A Placebo-Controlled, Double-Blind, Parallel-Group, 24 Month Study to Evaluate the Efficacy and Safety of E2609 in Subjects With Early Alzheimer's Disease


Alzheimer's Disease E2609 Elenbecestat Early Alzheimer's Disease Prodromal Alzheimer's Disease Dementia Dementia, Alzheimer's type Mild Cognitive Impairment MissionAD2 Alzheimer Disease Elenbecestat (E2609) Elenbecestat (E2609) 50 mg


You can join if…

Open to people ages 50-85

  • Mild cognitive impairment due to AD or mild AD dementia including
  • Mini Mental State Examination score equal to or greater than 24
  • CDR global score of 0.5
  • CDR Memory Box score of 0.5 or greater
  • Impaired episodic memory confirmed by a list learning task
  • Positive biomarker for brain amyloid pathology as indicated by either amyloid PET or CSF assessment or both
  • Study partner able to support the participant for duration of the study.
  • Provide written informed consent. Participants must, in the investigator's judgment, have the capacity to consent.

You CAN'T join if...

  • Females who are breastfeeding or pregnant at Screening or Baseline. Females of child-bearing potential must use a highly effective method of contraception throughout the entire study period and for 28 days after study drug discontinuation
  • Any condition that may be contributing to cognitive impairment above and beyond that caused by the participant's AD
  • Participants with a history of seizures within 5 years of Screening
  • History of transient ischemic attacks or stroke within 12 months of Screening
  • Psychiatric diagnosis or symptoms (e.g., hallucinations, major depression, delusions, etc.)
  • Suicidal ideation or any suicidal behavior within 6 months before Screening or has been hospitalized or treated for suicidal behavior in the past 5 years
  • Have any contraindications to magnetic resonance imaging (MRI) scanning or
  • Have lesions that could indicate a dementia diagnosis other than AD on brain MRI
  • Exhibit other significant pathological findings on brain MRI.
  • Participants who have a history of moderate to severe hepatic impairment (eg, Child-Pugh Class B or C)
  • Results of laboratory tests conducted during Screening that are outside the following limits:
  • Absolute lymphocyte count below the lower limit of normal (LLN)
  • Thyroid stimulating hormone above normal range
  • Abnormally low Vitamin B12 levels
  • Participants at risk of increased risk of infection
  • Have received any live/live attenuated vaccine in the 3 months before randomization
  • Any chronic inflammatory disease that is not adequately controlled or that requires systemic immunosuppressive or immunomodulatory therapy
  • Any other clinically significant abnormalities
  • Severe visual or hearing impairment
  • A prolonged corrected QT (QTc) interval (QTcF greater than 450 milliseconds [ms])
  • Malignant neoplasms within 5 years of Screening
  • Known or suspected history of drug or alcohol abuse
  • Taking prohibited medications, which must be reviewed with the Investigator
  • Have participated in a recent clinical study

Note: Other protocol-defined Inclusion/Exclusion Criteria may apply.


  • Facility #1 accepting new patients
    Los Angeles California 90095 United States
  • Facility #1 accepting new patients
    Irvine California 92614 United States
  • Facility #1 completed
    Santa Monica California 90404 United States
  • Facility #2 accepting new patients
    Santa Ana California 92704 United States
  • Facility #1 accepting new patients
    Laguna Hills California 92653 United States
  • Facility #1 completed
    Santa Ana California 92705 United States


accepting new patients
Start Date
Completion Date
Eisai Co., Ltd.
Phase 3
Study Type
Last Updated