Could a common cold sore drug slow Alzheimer's?
NCT ID NCT04710030
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This study tested whether the antiviral drug valacyclovir (Valtrex) could slow brain changes linked to Alzheimer's in 50 people with mild cognitive impairment who also had herpes simplex virus antibodies. Participants took either valacyclovir or a placebo for 52 weeks. The goal was to see if the drug reduced amyloid buildup in the brain and helped preserve memory and thinking skills.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- valacyclovir (Valtrex)
- What this could lead to
- If it works, this could point toward a new way to slow memory decline in people with early Alzheimer's risk.
- What could go wrong
- This is a small, early-phase trial with only 50 participants. The drug may not affect Alzheimer's-related brain changes, and side effects from high-dose valacyclovir are possible.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
-
50 people
The number who actually took part.
- Started
-
Feb 2021
- Finished
-
Dec 2024
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
50 to 95 years
- Sex
-
Anyone
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Males and females ages 50-95. Females must be postmenopausal, defined as 12 consecutive months without menstruation. (Patient Report) 2. Diagnosis of MCI (includes eMCI and lMCI by ADNI criteria)(Neuropsychological Evaluation) 3. Folstein Mini Mental State (MMSE) greater than or equal to 23/30. (Neuropsychological Evaluation) 4. Patient retains capacity to consent for him/herself. (Physician Evaluation) 5. At screening, patients must test positive for serum antibodies to HSV1 or HSV2. (Laboratory Tests) 6. Use of cholinesterase inhibitors or memantine is not required but will be permitted. If already prescribed, doses of these medications must be stable for 1 month prior to study entry. Patients are permitted to receive cholinesterase inhibitors and/or memantine throughout the duration of the study. Any changes to the medication will be documented in the participant research chart. Medications given for other medical reasons, e.g., antidiabetic or anti-hypertensive medications, will not be altered for the purposes of this trial and the patient's primary physician may adjust such medications as medically indicated throughout the trial. Details of concomitant medication use will be documented at all visits and will be available for statistical analysis.(Patient Report) 7. Either PET amyloid scan positivity at screening, or prior CSF biomarker positive for AD. (Medical Records or through completing a PET scan as part of screening) Exclusion Criteria: 1. Current clinical diagnosis of schizophrenia, schizoaffective disorder, other psychosis, bipolar disorder or current major depression by DSM-5 criteria. Prior history of major depression will not be exclusionary. (Physician Evaluation) 2. Active suicidal intent or plan based on clinical assessment. (SRMP Assessment by Study Physician) 3. Current or recent (past 6 months) alcohol or substance use disorder (DSM-5 criteria). (Physician Evaluation) 4. Current diagnosis of other major neurological disorders, including Parkinson's disease, multiple sclerosis,CNS infection, Huntington's disease, and amyotrophic lateral sclerosis. (Physician Evaluation) 5. Clinical stroke with residual clinical deficits. MRI findings of cerebrovascular disease (small infarcts, lacunes, periventricular disease) in the absence of clinical stroke with residual neurological deficits will not lead to exclusion. (Physician Evaluation) 6. Acute, severe, unstable medical illness. For cancer, patients with active illness or metastases in the last 12 months will be excluded, but past history of successfully treated cancer will not lead to exclusion. (Physician Evaluation) 7. Sitting blood pressure \> 160/100 mm Hg. (Physician Evaluation) 8. Renal failure as determined by an estimated Glomerular Filtration Rate (GFR) \< 44 ml/min/1.73m2. (Laboratory Report) 9. Serum vitamin B12 levels below the normal range. (Laboratory Report) 10. Patients with thyroid stimulating hormone (TSH) levels above 4.94 mlU/L. (Laboratory Report) 11. Use of benzodiazepines in lorazepam equivalent doses equal to or greater than 2 mg daily. (Patient Report) 12. For MRI, metal implants and pacemaker, and claustrophobia such that the patient refuses MRI. (Patient Report) 13. Radiation exposure in the prior 12 months that, together with 18F- Florbetapir will be above the FDA annual radiation exposure threshold. (Patient Report and Physician Evaluation) 14. Severe vision or hearing impairment that would prevent the participant from performing the psychometric tests accurately. This will be a clinical determination by the study physician without formal testing or audiometry.(Physician Evaluation)
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
New York State Psychiatric Institute
New York, New York, 10032, United States
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