Pritelivir for herpes simplex virus

Researchers in the USA have been trialling a new drug pritelivir in a phase II trial reported in this paper1 by Wald et al. Pritelivir is a new herpes simplex virus (HSV) helicase-primase inhibitor which reduces genital shedding and HSV lesions. In this study, pritelivir and valaciclovir were compared in a randomised double-blinded crossover trial at four centres in the USA and the study recruited 92 participants (male and female) who had a history of four to nine outbreaks of HSV-2 per year. Participants were asked to undertake genital swabs four times a day and were randomised to receive pritelivir for 28 days followed by a washout period of 28 days and then 28 days of valaciclovir, or vice versa with a primary end point of genital shedding. Fifty six out of the 91 randomised participants (63% of which were female) completed the trial, and genital shedding was seen in 2.4% vs 5.3% patients in the pritelivir versus valaciclovir arms with a relative risk (RR) …