Feasibility and Effects of Valaciclovir Treatment in Persons With Early Alzheimer's Disease

This study investigates the effects of valaciclovir treatment to individuals with Alzheimer's disease (AD) or Mild Cognitive Impairment of Alzheimer's Disease Type. It is an open pilot trial where 36 participants will receive 4 weeks of oral valaciclovir treatment. To find 36 persons fulfilling inclusion criteria, up to 120 persons will be screened. Important inclusion criteria are Herpes Simplex Virus (HSV) Immunoglobulin G (IgG)-positivity (HSV carriage), Apolipoprotein E allele 4 carriage and sufficient kidney function (estimated glomerular filtration rate above 30 ml/min). All participants must give their informed consent to participation. The valaciclovir dose will be 500 mg three times daily the first week and 1000 mg three times daily week 2-4. Participants will be investigated using different measures before and after the treatment period: Mini Mental State Examination to assess cognitive function, Cerebrospinal fluid biomarkers of Alzheimer's disease and \[18F\]-FHBG-PET/CT (9-\[4-\[18F\]fluoro-3-(hydroxymethyl)butyl\]guanine positron emission tomography/computed tomography)) to possibly indicate active HSV infection within the central nervous system.