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FDA Panel Recommends Approval for Gardasil in Boys and Men
“Today's discussion with the Advisory Committee brings the public health community closer to being able to provide GARDASIL to both men and women," said Anna R. Giuliano, Ph.D., Moffitt Cancer Center.
GARDASIL has been approved for use in the U.S. since June 2006 and is currently indicated for use in girls and young women 9 through 26 years of age for the prevention of cervical, vulvar and vaginal cancers caused by HPV types 16 and 18; genital warts caused by HPV types 6 and 11; and precancerous or dysplastic lesions caused by HPV types 6, 11, 16 and 18. More than 50 million doses have been distributed worldwide through June 2009, although the number of doses administered is not known.
Data for use of GARDASIL in boys and men presented
Clinical trials presented to the Advisory Committee evaluated the efficacy, immunogenicity and safety of GARDASIL in boys and men 9 to 26 years of age. Vaccine efficacy in males was evaluated in a randomized, double-blind, placebo-controlled trial. A total of 4,055 men were enrolled and received at least one dose of GARDASIL or placebo. Of these, 3,457 were heterosexual men aged 16 to 23 years and 598 were men who have sex with men aged 16 to 26 years.
The per-protocol efficacy (PPE) population was the predefined primary population for the demonstration of efficacy in 16- to 26-year-old men. As defined, this population included subjects who were not infected with HPV vaccine types at the start of the study, nor did they become infected with HPV vaccine types during the course of the vaccination series. These subjects were seronegative and HPV DNA negative to HPV vaccine types at day one, and HPV DNA negative through the vaccination series to month seven. This population also received the three shot series within a one-year time period and generally did not deviate from the protocol. The cases of the primary endpoint of external genital lesions (EGL) were counted starting after month seven.
Analyses were also conducted in the Full Analysis Set (FAS) population. The FAS population included all participants who received at least one dose of vaccine or placebo and endpoint cases were counted after day one, the day after the first dose of vaccine was given. The key difference from the PPE population was that the FAS also included participants who had been previously exposed, were already infected with HPV types, or became infected before the completion of the three-dose vaccine series (not specific to 6, 11, 16 and 18).
Per protocol efficacy
In the PPE analysis, GARDASIL was 90.4 percent efficacious (95 percent CI: 69.2, 98.1) against HPV 6, 11, 16 and 18-related EGL. Of 34 cases of EGL, 31 were genital warts. All cases of genital warts were positive for HPV 6 and/or 11 (three cases in the vaccine group and 28 in the placebo group). GARDASIL was 89.3 percent efficacious (95 percent CI: 65.5, 97.9) against HPV 6/11-related external genital warts.
There were three cases of HPV 6/11/16/18-related penile/perianal/perineal intraepithelial neoplasia (PIN) in the PPE analysis and all were in the placebo group. No cases of penile/perianal/perineal cancers were observed in the vaccine or placebo groups during the study. Although vaccine efficacy against HPV 6/11/16/18-related PIN 1 or worse was 100 percent (95 percent CI:
Full analysis set
In the FAS analysis, GARDASIL was 65.5 percent efficacious (95 percent CI: 45.8, 78.6) against HPV 6, 11, 16 and 18 EGL. Of 104 cases of EGL, 95 were genital warts positive for HPV 6 and/or 11 (24 cases in the vaccine group and 71 in the placebo group). GARDASIL was 66.8 percent efficacious (95 percent CI: 46.5, 80.0) against HPV 6/11-related external genital warts in this analysis.
In immunogenicity studies, GARDASIL generated robust immune responses to HPV types 6, 11, 16 and 18 in 9- to 15-year old boys and 16- to 26-year old men.
Immunobridging studies in 9- to 15-year old boys demonstrated that boys had approximately two to three fold higher HPV type-specific antibody levels at month seven compared to 16- to 26-year old men. These data established the non-inferiority of the peak immune response as measured at month seven for all four HPV-types in boys as compared to men.
Safety data for GARDASIL
Compared with placebo recipients, a slightly higher proportion of vaccinees reported injection site (64.1 percent GARDASIL; 53.6 percent placebo) and systemic adverse experiences (37.2 percent GARDASIL; 32.6 percent placebo), the majority of which were reported as mild to moderate intensity. Subjects who reported a severe intensity systemic adverse experience and/or an injection-site adverse experience were comparable between the two groups (systemic adverse experiences reported: 4.3 percent in the GARDASIL group versus 3.0 percent in the placebo group; injection-site adverse experiences reported: 2.0 percent in the GARDASIL group versus 1.0 percent in the placebo group). Overall, the safety profile observed in boys and men 9 to 26 years of age in clinical studies was consistent with the safety profile observed in clinical studies in girls and women 9 to 26 years of age.
Source: Merck & Co.