Antiviral Medicine Could Help Halt Cognitive Decline in Early Alzheimer’s, Preliminary Data Show

Preliminary data from a Phase 2 study suggests that treating early Alzheimer’s disease patients who are positive for herpes simplex virus with an antiviral medicine may help halt their cognitive decline.

Hugo Lövheim, MD, PhD, at Umeå University, Sweden, presented the results in a presentation titled “Valz Pilot Study – Valaciclovir treatment to individuals with early Alzheimer’s disease” at the 14^th International Conference on Alzheimer’s and Parkinson’s Diseases and related neurological disorders, held March 26–31, in Lisbon, Portugal.

Accumulating evidence, including a previous study from Lövheim’s team, shows that infection by the herpes simplex virus type 1 (HSV1) is linked with Alzheimer’s disease. These results suggest that antiviral medicines, such as valacyclovir (marketed as Valtrex, among other brand names) may benefit Alzheimer’s disease patients.

To test the effects of valacyclovir, researchers are conducting a Phase 2 trial (NCT02997982) — called VALZ-Pilot — on 36 individuals with early Alzheimer’s disease, who have antibodies against HSV and carry the type 4 allele of the apolipoprotein E gene (APOE-ε4) — a genetic factor associated with a higher risk for developing early Alzheimer’s.

Participants receive treatment with valacyclovir for four weeks — first dose of 500 miligrams (mg) three times daily for the first week, followed by 1000 mg three times daily for the remaining three weeks.

Before and after the treatment, the patients’ cognitive function is assessed using the Mini-mental State Examination (MMSE), as are their levels of Alzheimer’s disease markers (such as tau protein) in the cerebrospinal fluid (CSF, the liquid bathing the brain and spinal cord). The MMSE is widely used to assess orientation, attention, memory, language, and visual-spatial skills. Higher scores in MMSE reflect lower cognitive impairment.

To date, 26 patients have been evaluated, and 10 have successfully completed the trial — six women and four men with an average age of 75.4 years and carrying different variants in the APOE gene.

Results from these 10 patients so far showed that MMSE scores improved from a mean of 20.8 to 21.9 after treatment with valacyclovir for four weeks. None reported side effects associated with the treatment.

“While several observational studies have indicated a role of HSV1 in AD (Alzheimer’s disease) development, clinical trials are needed to investigate whether antiviral drug treatment might affect disease processes and have beneficial effects to individuals with AD,” the researchers wrote.

“The ongoing VALZ clinical pilot drug trial might provide a first indication of such effects, but must be followed by larger placebo-controlled trials,” the team added.