Anal Dysplasia

February 22, 2010

Merck issued positive results from a phase III study of Gardasil for the prevention of anal intraepithelial neoplasia (AIN) and anal cancer associated with HPV types 6, 11, 16 and 18. This randomized, double-blind, placebo-controlled trial enrolled 598 males, 16-to-26 years old, who were sexually active with other men. The subjects received at least one dose of the Gardasil or placebo at the time of enrollment, and then again at two and six months. The cases of AIN and anal cancer were counted starting after month seven with an average follow up of 2.5 years. Gardasil prevented 77.5% of HPV 6, 11, 16, and 18-related AIN and anal cancer. A total of 29 subjects were diagnosed with HPV 6, 11, 16 or 18-related AIN during the study, with 24 cases in the placebo group and five in the vaccine group. No cases of HPV 11 or 18-related AIN were observed in the vaccine group. No cases of anal cancer were seen in either the placebo or vaccine group.