A randomized clinical trial of valacyclovir in multiple sclerosis

Area of Science:

• Neuroimmunology
• Viral Immunology
• Clinical Neurology

Background:

• Human Herpesvirus type-6 (HHV-6) is a suspected factor in multiple sclerosis (MS) pathogenesis.
• Valacyclovir, an antiviral medication, possesses a favorable safety profile.
• Understanding the potential of antiviral therapies in MS management is crucial.

Purpose of the Study:

• To evaluate the safety and tolerability of high-dose, long-term valacyclovir treatment in MS patients.
• To determine if valacyclovir can delay clinical or MRI-defined progression of MS.
• To investigate the potential role of HHV-6 in MS and the efficacy of its inhibition.

Main Methods:

• A two-year, double-blind, placebo-controlled study involving 58 MS patients stratified by severity.
• Randomized assignment to receive either valacyclovir (3000 mg/day) or a placebo.
• Clinical assessments included the Expanded Disability Status Scale (EDSS) and Ambulation Index (AI); brain MRI scans were used for imaging evaluation.

Main Results:

• Valacyclovir was well-tolerated, with no study discontinuations due to side effects or toxicity.
• Trends suggesting a clinical benefit of valacyclovir over placebo were observed in the severe MS subgroup, including time to first attack and attack rate.
• No statistically significant differences in clinical progression or MRI outcomes were detected between the valacyclovir and placebo groups.

Conclusions:

• High-dose valacyclovir over two years was safe and well-tolerated in MS patients.
• While not statistically significant, clinical measures indicated potential positive trends for valacyclovir in managing MS progression.
• MRI evaluations did not support a significant effect of valacyclovir on MS disease activity.