Health Canada approves GARDASIL for prevention of genital warts in males

Feb 23 2010

Today, Merck announced that Health Canada has approved GARDASIL(R) (Human Papillomavirus Quadrivalent (Types 6, 11, 16, and 18) Recombinant Vaccine) for boys and men nine through 26 years of age for the prevention of infection caused by HPV types 6, 11, 16, and 18 and genital warts caused by HPV types 6 and 11.

"I see a large number of men with genital warts which are both difficult and painful to treat," said Dr. Charles Lynde, a practising Dermatologist and Assistant Clinical Professor, University of Toronto. "We have many treatments for genital warts which are often not all that effective. With Health Canada's approval of the use of Merck's vaccine in males, now rather than treating them after the fact, the prevention of warts for both sexes is possible in this country."

"Often genital warts are imperceptible for many months, making it difficult for partners to see them," said Dr. Marni Wiseman, a Dermatologist and Assistant Professor at the University of Manitoba. "Once out in the open, genital warts can have a major impact on a couple's sexual relationship."

"Sophisticated research has shown viral DNA in the skin cells of young women at the location of genital warts after the warts have been destroyed and no longer visible," said Dr. Kirk Barber, a practising Dermatologist and Associate Clinical Professor of Dermatology at the University of Calgary. "I suspect that this is the reason that recurrence rates are so high in both young women and men."

"Social stigma is associated with all sexually transmitted diseases and genital warts is no exception," said Dr. Marc Steben, a Canadian expert in sexually transmitted infections.

"You feel invincible when you're young and getting genital warts has affected me. I kept to myself and I didn't date a lot after that. I am not at all comfortable talking about genital warts with friends, family, partners," admitted a young man who has been living with genital warts for 10 years.

HPV is the most common sexually transmitted infection in Canada and genital warts are common among males. Most (90 per cent) genital warts are caused by HPV types 6 and 11; more than 40,000 new cases of ano-genital warts are estimated yearly for Canadian men and women.

High level of shared HPV infections

In a Canadian study recently published in Sexually Transmitted Diseases more than half (56 per cent) of young people in a new sexual relationship were infected by HPV. Those infected were, on average, infected with 2.8 types of HPV.

Men play an important role in the transmission of HPV to their sexual partners. Research has shown a high level of sharing of HPV infections between couples who recently became infected.

The data consistently support the sexually transmitted nature of HPV and the role of men in infecting women, who subsequently can develop HPV-related ano-genital cancers and genital warts. Based on these various lines of evidence it is expected that decreasing the risk of HPV infection in men through vaccination should decrease the risk of infection in their sexual partners, thereby providing additional public health benefit.

Significant decline in genital warts

In the Phase III clinical study conducted over three years with more than 4,000 males ages 16 to 26, the quadrivalent HPV vaccine was 89.4 per cent efficacious in reducing the incidence of genital warts related to HPV types 6 and 11 among males who were naïve to HPV types 6, 11, 16, and 18.

A separate Australian retrospective study to assess the impact of the national vaccination program with the quadrivalent HPV vaccine on females showed early benefits from vaccination. The study found a significant decline in genital warts cases in the targeted female population as well as a drop in genital warts among heterosexual but not homosexual men.

GARDASIL(R) is also indicated in girls and women nine through 26 years of age for the prevention of infection caused by the human papillomavirus (HPV) types 6, 11, 16, and 18 and the following diseases associated with these HPV types:

- Cervical cancer (cancer of the lower end of the uterus or womb) - Vulvar (the outside of the female genital area) and vaginal cancers - Genital warts (condyloma acuminata) - Cervical adenocarcinoma in situ (AIS) - non invasive cancer - Cervical intraepithelial neoplasia (CIN) grade 2 and grade 3 (changes in cells of the cervix that have a risk of turning into cancer) - commonly called pre-cancers - Vulvar intraepithelial neoplasia (VIN) grade 2 and grade 3 (abnormal lesions on the outside of the female genitalia that have a risk of turning into cancer) - commonly called pre-cancers - Vaginal intraepithelial neoplasia (VaIN) grade 2 and grade 3 (abnormal lesions on the vagina that have a risk of turning into cancer) - commonly called pre-cancers - Cervical intraepithelial neoplasia (CIN) grade 1 (changes in cells of the cervix that often clear up on their own) - commonly called low- grade lesions