Source: www.vaccinerx.com
Author: written by Vaccind Rx Daily Staff

The four-type (6,11,16,18) human papillomavirus (HPV) vaccine Gardasil® is also effective in men according to the primary analysis from a pivotal phase III clinical study. In previously uninfected men aged 16 to 26 years*, Gardasil® prevented 90% (95%CI: 69, 98) of external genital lesions caused by HPV types 6, 11, 16 or 18. The data were presented this week at the congress of the European Research Organisation on Genital Infection and Neoplasia (EUROGIN) in Nice, France.1

The study was designed to determine the efficacy of Gardasil® in preventing HPV 6,11,16 or 18- related ‘external genital lesions’ a composite endpoint that included genital warts, penile / perineal / perianal lesions† (PIN, PIN2/3; potential pre-cursors to cancer) and penile / perineal / perianal cancer.

In the study, Gardasil was 90.4% effective in reducing external genital lesions (3 cases in the vaccine group vs 31 cases in the placebo group; 95% CI:69.2, 98.1). All three cases observed in the HPV vaccinated group were of genital warts, resulting in a vaccine efficacy of 89.4% (95% CI [65.5, 97.9]) in preventing genital warts in men.

There were no cases of penile / perineal / perianal lesions in the vaccinated group vs. 3 cases in the placebo group. There were no cases of penile / perineal / perianal cancer in either group. At the time of this analysis, the study had a mean duration of about 29 months.

No HPV vaccine-related serious adverse events were reported. A slightly higher proportion of study participants reported injection-site adverse events in the vaccine group compared to the placebo group (60.1 % vs. 53.7 %).

The primary analysis was predetermined in the study protocol to be conducted after at least 32 cases of external genital lesions were observed. The study is still ongoing, and additional data will become available in the future.

“Although rarer than those in women, HPV-related genital cancers in men are serious diseases worth preventing; genital warts are as frequent in men as in women. In addition, men can transmit HPV to women who can develop cervical, vulvar and vaginal pre-cancer or cancer, and genital warts”, says Dr Nicholas Kitchin, Medical Director of Sanofi Pasteur MSD. “Based on these first encouraging results and future data we will have to define, together with the competent authorities and experts, how to approach a possible HPV vaccination of men in the future. Until this is done, vaccinating girls and young women remains the priority.”

Gardasil® is currently indicated for use in 9- to 15-year old girls and boys and 16 to 26-year old women for the prevention of cervical cancer, cervical, vulvar and vaginal pre-cancers and external genital warts caused by HPV types 6, 11, 16 and 18.

Current experience with the four-type HPV vaccine
Thirty years after the discovery that human papillomavirus (HPV) can cause cervical cancer, 15 years after the start of vaccine development and two years after the approval of the four-type (6,11,16,18) HPV vaccine Gardasil®, vaccination to prevent cervical cancer and other HPV-related diseases has been widely implemented.

Details about the new study results
In this randomized, double-blind, placebo-controlled trial, 4,065 young men aged 16-26 were administered quadrivalent HPV vaccine or placebo at enrolment, month 2, and month 6. Participants were not infected with one or more of the four vaccine HPV types 6, 11, 16 or 18 through one month post dose three and were randomised in a 1:1 ratio to receive three doses of either quadrivalent HPV vaccine or placebo at day one, two months and six months, with 36 months of planned follow-up from day one. At the time of vaccination, participants had no evidence of genital lesions, no history of genital warts and five or fewer lifetime sexual partners. 1,397 men in the vaccine group and 1,408 men in the placebo who had received all three doses of either quadrivalent HPV vaccine or placebo were included in the analysis.

Indication of Gardasil®
Gardasil® (Human Papillomavirus Vaccine [Types 6, 11, 16, 18] (Recombinant, adsorbed)) is a vaccine for the prevention of premalignant genital lesions (cervical, vulvar and vaginal), cervical cancer and external genital warts (condyloma acuminata) causally related to Human Papillomavirus (HPV) types 6, 11, 16 and 18. The indication is based on the demonstration of efficacy of Gardasil® in adult females 16 to 26 years of age and on the demonstration of immunogenicity of Gardasil® in 9- to 15-year old children and adolescents. Protective efficacy has not been evaluated in males. The use of Gardasil® should be in accordance with official recommendations.

* who were not infected with one or more of the four vaccine HPV types at enrolment and one month after complete vaccination † PIN = penile/perineal/perianal intraepithelial neoplasia. Penile/perineal/perianal is defined as related to or affecting the penis (penile), the area between the anus and the scrotum (perineal), or the opening of the rectum to the outside of the body (perianal).