Age: 60 - 70+
Healthy Volunteers: Not accepted
Inclusion Criteria:
1. The Sponsor will rely on NIA-AA Alzheimer's Disease Diagnostic Guidelines for Early Symptomatic Alzheimer's Disease (AD) with a 20-30 MMSE score, Clinical Dementia Rating (CDR) global score of 0.5 or 1, and impaired memory performance below an education adjusted cut-off score on the Logical Memory II subscale delayed paragraph recall (LM-IIa) of the Wechsler Memory Scale- Revised (WMS-R) (127) (≥16 years: ≤8; 8-15 years: ≤4; 0-7 years: ≤2).
2. Age between 60 and 85 years (inclusive).
3. Good general health with no disease likely to interfere with the study assessments.
4. On a stable medication regimen for eight weeks prior to the study and is anticipated to remain stable during the study.
5. Subject is not pregnant, lactating, or of childbearing potential (i.e., women must be two years post-menopausal or surgically sterile). If a woman is of childbearing potential, her partner must use barrier contraception throughout the study.
6. Amyloid-positive PET scan (performed only if the subject meets all other inclusion criteria). An amyloid-positive PET scan is classified by an SUVR composite score cutoff of 1.18 units. Prior evidence of amyloid positivity by PET or CSF will also be accepted for eligibility.
7. Ability to understand and provide informed consent.
8. Has availability of a study partner who has regular contact with the participant and knows him/her well.
Exclusion Criteria:
1. Any significant neurologic disease including Parkinson's disease, stroke, multiinfarct dementia, frontotemporal dementia, Lewy body dementia, normal pressure hydrocephalus, brain tumor, brain hemorrhage with persistent neurologic deficits, progressive supra-nuclear palsy, seizure disorder, multiple sclerosis, or history of significant head trauma followed by persistent neurologic deficits or known structural brain abnormalities.
2. Clinically significant or unstable medical conditions, including uncontrolled hypertension, uncontrolled diabetes, or significant cardiac, pulmonary, renal, hepatic, endocrine, or other systemic diseases.
3. History of autoimmune disease.
4. Current treatment with immunomodulatory or immunosuppressive drugs or corticosteroid administration by any route of administration (including nasal corticosteroids) within the past month.
5. Major depressive disorder (within the past 1 year), or a history of bipolar disorder, or a history of schizophrenia.
6. History of alcohol or substance abuse or dependence within the past two years.
7. History of malignancy within the past 3 years.
8. Clinically significant abnormalities in screening laboratories (defined as greater than mild on the FDA's vaccine toxicity grading scale).
9. Participation in another clinical trial of an investigational drug concurrently or within the past 30 days.
10. Low affinity TSPO binders (for PET ligand \[18F\]PBR06) determined by having a Thr/Thr polymorphism in the TSPO gene at screening.
11. Sensitivity to florbetapir F18.
12. Active COVID-19 disease.
13. Amyloid-negative PET scan.
14. COVID-19 vaccine within the past ten days or any other vaccine within the past seven days (at dosing)