ACIP reviews HPV vaccination in boys and men

The quadrivalent human papillomavirus vaccine is providing high rates of protection against persistent infection caused by vaccine types in male trial participants, translating into efficacy against anal disease and risk factors for anal epithelial neoplasia 2/3, according to a Merck representative who presented data on the vaccine at the Advisory Committee on Immunization Practices meeting earlier today.

Richard Haupt, MD,of Merck, said the annual incidence of anal cancer in men and women has been increasing.

“These cancers are predominantly HPV-related,” he said.

In the Merck study, about 4,000 men were randomly assigned to receive three doses of the vaccine or placebo and followed for 36 months. About 600 of those were men who have sex with men.

“We saw participants every six months,” Haupt said. “External penile, scrotal, perineal and perianal swabs were taken. MSM also received an intra-anal swab and anal pap smears.”

The primary objective was to determine the safety of the vaccine in men. Efficacy endpoints included a reduction in external genital lesions due to vaccine-type infections and intra-anal genital lesions in MSM. Secondary endpoints were focused on duration of persistent infection.

“Compared with placebo, the efficacy of the vaccine against external genital lesions was over 90%,” Haupt said. “The per-protocol efficacy in MSM was more than 77%. The safety data were comparable to women. There were no serious adverse events reported and fewer injection site complaints. The safety profile was very clean.

“We also were able to demonstrate efficacy at epithelial and mucosal sites,” Haupt said. “This shows a strong benefit of the vaccine against HPV types and related diseases.”

The key issues to be considered as the vaccine is used more routinely in men include, “efficacy, epidemiology and burden of disease in males, programmatic issues and cost-effectiveness,” said Laura Markowitz, MD of the CDC, who also spoke at the meeting. “However, with regard to that last point, cost-effectiveness depends on a variety of assumptions, including that the vaccine is most effective when coverage in females is low and when all complications are covered in models.”

Markowitz said many analyses of the vaccine in men are based on 75% coverage of the vaccine, but that coverage across the United States often falls short of that mark, even in 11- and 12-year-old girls.

“Cost-effectiveness analyses need to be clearer and more standardized,” Markowitz said. “In particular, there needs to be further consideration of MSM and the feasibility of reaching MSM.” – by Rob Volansky