FDA panel backs Cervarix for women, Gardasil for men
A Food and Drug Administration advisory panel today recommended that the agency approve the Cervarix vaccine against human papilloma virus (HPV) for use in women and that it expand the approval of the Gardasil HPV vaccine to use in men. The FDA is not obligated to follow the recommendations from its committees of outside experts, but it generally does so.
About 20 million Americans are infected by HPV each year. Most infections are cleared by the body, but the virus is thought to be responsible for an estimated 11,000 cases of cervical cancer each year, with 4,000 deaths. In men, HPV is linked with anal cancer, which strikes perhaps 2,000 men yearly, and with penile cancer, which is even rarer.
Gardasil was introduced in 2006 by Merck & Co. and protects against two strains of HPV that are associated with 70% of cervical cancers. It is also protective against two other strains that are associated with 90% of genital warts, which are sometimes precursors of anal and penile cancer. It is now recommended for use in girls and women ages 10 to 25.
SmithKlineGlaxo applied for approval of Cervarix, which protects against the same two cervical cancer strains as Gardasil, in 2007, but the agency asked for more information because of reports suggesting that use in pregnant women might lead to miscarriages. The advisory panel concluded that the evidence linking the vaccine to the miscarriages is not very good, although it suggested that the vaccine carry a warning about the possibility. The vaccine should "be marketed with the usual caveat that it shouldn't be used during pregnancy," said panel member Dr. Kenneth Noller of the Tufts University School of Medicine.
The panel also said that marketing for Gardasil could be extended to men ages 9 to 26, but conceded that probably not many would be likely to be immunized -- both because of the rarity of penile and anal cancers and the high cost of the vaccine, $400 for a three-dose regimen. Critics also argue that it is not yet clear how long the protection provided by the vaccine persists. The companies have studied it for only five years in women and three in men, and there are some hints that the protection may fade.
Critics of the vaccine claim that Gardasil was associated with 6,723 adverse events in 2008, including more than 1,000 considered serious and 142 that were considered life-threatening. The panel concluded, however, that it was "unlikely" that most of the events were related to the vaccine.
-- Thomas H. Maugh II