An international, randomized, double-blind, placebo-controlled, study of valacyclovir for the suppression of herpes simplex virus type 2 genital herpes in newly diagnosed patients.

Background: Antiviral suppressive therapy of genital herpes is often initiated based on the established pattern of recurrences in an individual. Because most persons with first episode herpes simplex virus type 2 (HSV-2) infection experience recurrences and because viral shedding occurs frequently in the first year after infection, we examined the strategy of initiating suppressive therapy shortly after diagnosis of genital HSV-2 infection.

Subjects And Methods: From June 16, 2004 to July 26, 2006, 384 subjects from 74 sites in the United States, Canada, Argentina, Brazil, and Chile who were newly diagnosed with a first recognized episode of genital herpes at the time of the screening visit or within 3 months before the screening visit were randomized (2:1) to receive valacyclovir 1 g once daily or placebo for 24 weeks. Subjects were instructed to return to clinic during suspected genital herpes outbreaks for clinician confirmation of recurrences.

Results: Valacyclovir significantly prolonged the time to first recurrence of HSV-2 genital herpes in newly diagnosed subjects compared with placebo, with approximately 43% of subjects on placebo and 71% of subjects on valacyclovir recurrence-free at 24 weeks (P <0.001). Valacyclovir significantly reduced the mean number of genital HSV-2 recurrences per month occurring during the 24-week study period (0.11 for valacyclovir, 0.48 for placebo, P <0.001). Adverse events were comparable in the valacyclovir and placebo arms.

Conclusion: Valacyclovir 1 g once daily administered for 24 weeks was well-tolerated and effective in suppressing genital herpes recurrences in immunocompetent newly diagnosed persons without an established recurrence pattern.