The U.S. Food and Drug Administration today approved the vaccine Gardasil for the prevention of
anal cancer and associated precancerous lesions due to human papillomavirus (HPV) types 6, 11, 16,
and 18 in people ages 9 through 26 years.
Gardasil is already approved for the same
age population for the prevention of cervical, vulvar, and vaginal cancer and the associated
precancerous lesions caused by HPV types 6, 11, 16, and 18 in females. It is also approved for the
prevention of genital warts caused by types 6 and 11 in both males and females.
“Treatment for anal cancer is challenging; the use of Gardasil as a method of prevention is
important as it may result in fewer diagnoses and the subsequent surgery, radiation or chemotherapy
that individuals need to endure,” said Karen Midthun, M.D., director of the FDA’s Center
for Biologics Evaluation and Research.
Although anal cancer is uncommon in the general
population, the incidence is increasing. HPV is associated with approximately 90 percent of anal
cancer. The American Cancer Society estimates that about 5,300 people are diagnosed with anal
cancer each year in the United States, with more women diagnosed than men.
Gardasil’s ability to prevent anal cancer and the associated precancerous lesions [anal
intraepithelial neoplasia (AIN) grades 1, 2, and 3] caused by anal HPV-16/18 infection was studied
in a randomized, controlled trial of men who self-identified as having sex with men (MSM). This
population was studied because it has the highest incidence of anal cancer. At the end of the study
period, Gardasil was shown to be 78 percent effective in the prevention of HPV 16- and 18-related
AIN. Because anal cancer is the same disease in both males and females, the effectiveness data was
used to support the indication in females as well.
Gardasil will not prevent the
development of anal precancerous lesions associated with HPV infections already present at the time
of vaccination. For all of the indications for use approved by the FDA, Gardasil's full potential
for benefit is obtained by those who are vaccinated prior to becoming infected with the HPV strains
contained in the vaccine.
Individuals recommended for anal cancer screening by their
health care provider should not discontinue screening after receiving Gardasil.
of May 31, 2010, more than 65 million doses of Gardasil had been distributed worldwide, since its
approval in 2006 according to the manufacturer, Merck and Co. Inc, of Whitehouse Station, N.J. The
most commonly reported adverse events include fainting, pain at the injection site, headache,
nausea, and fever. Fainting is common after injections and vaccinations, especially in adolescents.
Falls after fainting may sometimes cause serious injuries, such as head injuries. This can be
prevented by keeping the vaccinated person seated for up to 15 minutes after vaccination. This
observation period is also recommended to watch for severe allergic reactions, which can occur
after any immunization.