HPV Vaccine against Anal HPV Infection and Anal Intraepithelial Neoplasia

The rate of anal cancer is increasing among both women and men, particularly men who have sex with men. Caused by infection with human papillomavirus (HPV), primarily HPV type 16 or 18, anal cancer is preceded by high-grade anal intraepithelial neoplasia (grade 2 or 3). We studied the safety and efficacy of quadrivalent HPV vaccine (qHPV) against anal intraepithelial neoplasia associated with HPV-6, 11, 16, or 18 infection in men who have sex with men.

In a substudy of a larger double-blind study, we randomly assigned 602 healthy men who have sex with men, 16 to 26 years of age, to receive either qHPV or placebo. The primary efficacy objective was prevention of anal intraepithelial neoplasia or anal cancer related to infection with HPV-6, 11, 16, or 18. Efficacy analyses were performed in intention-to-treat and per-protocol efficacy populations. The rates of adverse events were documented.