NCT03071224

Who might be able to join this trial:

For everyone in the trial:

• You must be willing and able to sign a consent form before anything begins
• Women must either be surgically unable to have children (through hysterectomy, removal of ovaries, or tubal ligation), be post-menopausal for at least 1 year, or agree to use two forms of contraception (one being a barrier method like a condom) during the study
• Men must agree to use two forms of contraception (one being a barrier method) during the study, and must not donate sperm for the duration of the study
• You must be willing and able to follow the study procedures

For healthy volunteers:

• You must be aged 50 or older and be generally healthy with no significant findings at a physical check-up
• You must have no signs of memory or thinking problems, as judged by the study doctor
• A brain scan must show no significant build-up of amyloid (a protein linked to Alzheimer's disease)
• You must have no family history of Alzheimer's disease or other brain diseases linked to dementia
• You must score 0 on a standard memory and thinking assessment called the CDR
• You must score 28 or above on a standard memory test called the MMSE

For people with a diagnosis of probable Alzheimer's disease:

• You must be aged between 50 and 80 years old
• You must have a diagnosis of probable Alzheimer's disease that is mild in severity, based on recognised medical criteria
• You must score 0.5 or higher on the CDR assessment
• You must score 26 or below on the MMSE memory test
• A brain scan must show significant amyloid build-up (either from a recent scan or one done within the last 12 months)
• A brain MRI must support the Alzheimer's diagnosis with no signs of other significant brain conditions
• Any medications you take for Alzheimer's symptoms must have been on a stable dose for at least 30 days before the study starts
• A caregiver or legally authorised representative must also sign the consent form if applicable
• You must have a caregiver who can accompany you to visits if needed

For everyone in Cohort 3 only (a specific group within the trial):

• You must be an active smoker at the time you first give your consent

Who may not be able to join:

For everyone in the trial:

• You have a current or past history of alcohol or drug abuse
• You have significant abnormal results on laboratory tests or a serious unstable medical condition
• You have taken part in a trial of an investigational drug or device within the last 30 days
• Your total radiation exposure from previous research or medical care in the past year, combined with this study, would exceed safe annual limits set by US federal guidelines
• You are pregnant, breastfeeding, or currently lactating
• You have significant problems with your digestive system, heart, liver, kidneys, blood, hormones, immune system, lungs, or other serious medical conditions
• Your veins are not suitable for repeated blood draws
• Your MRI results show signs of significant brain abnormalities such as strokes, infections, tumours, fluid build-up, or other brain conditions
• You have certain implants or devices in your body (such as a pacemaker, insulin pump, cochlear implant, or certain metal implants) that are not safe for MRI, or you have a history of severe claustrophobia in MRI machines

For people with Alzheimer's disease only:

• You have received any treatment targeting amyloid or tau proteins (substances linked to Alzheimer's disease) within the last 3 months

Important: Always verify eligibility with the trial site directly before applying.