Merck & Co. received FDA approval to market Gardasil for the prevention of anal cancer caused by HPV types 16 and 18 in males and females who are 9 through 26 years of age. It was also sanctioned for both genders in the same age group for the prevention of anal intraepithelial neoplasia (AIN) grades 1, 2, and 3 caused by HPV types 6, 11, 16, and 18.
The decision was based on a randomized, controlled trial of men who self-identified themselves as having sex with men. This population was studied because it has the highest incidence of anal cancer.
Gardasil was shown to be 78% effective in the prevention of HPV 16- and 18-related intraepithelial neoplasia grades 1, 2, and 3. 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.
The vaccine was initially approved in the U.S. in 2006 for cervical, vulvar, and vaginal cancers as well as genital warts. Sales, however, have been declining since 2008 due to controversies over vaccination as well as competition from GlaxoSmithKline’s Cervarix. GSK’s vaccine was approved in October 2009 for the prevention of cervical cancer and related precancers caused by HPV 16 and 18 in females 10 through 25 years of age.
Although anal cancer is uncommon in the general population, the incidence is increasing, according to FDA. HPV is associated with approximately 90% of anal cancer, the agency adds. The American Cancer Society estimates that about 5,300 people are diagnosed with anal cancer each year in the U.S., with more women diagnosed than men.
“Treatment for anal cancer is challenging,” says Karen Midthun, M.D., director of the FDA’s Center for Biologics Evaluation and Research. “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.”
Gardasil is indicated for females between 9 and 26 for the prevention of cervical, vaginal, and vulvar cancers and the associated precancerous lesions caused by HPV types 6, 11, 16, and 18 in females. It is also sanctioned for genital warts caused by HPV types 6 and 11 in both men and women between 9
and 26 years of age.
“Gardasil is the only HPV vaccine available for use in both males and females, and the only one indicated to help prevent cervical, vaginal, vulvar, and anal cancers and precancers as well as genital warts caused by certain types of HPV,” comments Richard M. Haupt, M.D., executive director, Merck Research Laboratories.
It is estimated that HPV types 16 and 18 account for approximately 75% of cervical cancers, 70% of vaginal cancers, and 40% to 50% of vulvar cancers, according to the company. HPV types 6 and 11 cause approximately 90% of all genital warts cases, Merck adds.
As of May 31, more than 65 million doses of Gardasil had been distributed worldwide, according to Merck. Merck reported third-quarter 2010 sales for the vaccine as $316 million, a 2% increase from the same quarter in 2009. Total worldwide sales for 2009, however, dipped 20% from 2008 to $1.1 billion.