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

Abstract

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. 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. 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. 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.