Gardasil's FDA Approval Now Includes Some Vaginal And Vulvar Cancers

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Main Category: Cervical Cancer / HPV Vaccine
Also Included In: Women's Health / Gynecology;  Immune System / Vaccines
Article Date: 15 Sep 2008 - 8:00 PDT

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The US Food and Drug Administration (FDA) has approved Merck's cervical vaccine Gardasil for protecting against vaginal and vulvar cancers caused by Human Papillomavirus (HPV) types 16 and 18 in girls and women aged from 9 to 26. The agency announced its decision to the press on Friday 12th September, in a FDA News page on its website.

Director of the FDA's Center for Biologics Evaluation and Research, Dr Jesse L Goodman said:

"There is now strong evidence showing that this vaccine can help prevent vulvar and vaginal cancers due to the same viruses for which it also helps protect against cervical cancer."

"While vulvar and vaginal cancers are rare, the opportunity to help prevent them is potentially an important additional benefit from immunization against HPV," added Goodman.

Gardasil won FDA approval for use as a vaccine against cervical cancer caused by HPV 16 and 18 in girls and women from 9 to 26 years old in 2006. At that time the approval also included use against precancerous lesions caused by HPV 6, 11, 16 and 18, as well as genital warts caused by types 6 and 11.

There are more than 100 types of HPV, 30 of which spread through sexual contact, helping to make HPV the most common sexually transmitted infection in the US with over 6 million new cases a year. Types 16 and 18 cause 70 per cent of cervical cancers, and also cause some types of vulvar and vaginal cancers, although the exact percentages are not known.

For most women, their immune system kills HPV and they don't experience serious health problems, but in some cases, HPV can lead to abnormal cell growth in the cervix, vagina, vulva, and other areas and these pre-cancerous growths can turn into cancer many years later.

To win approval for Gardasil as a vaccine against vulvar and vaginal cancer, Merck followed more than 15,000 participants from the original trial for another two years. About half the participants had been given Gardasil and the other half, the controls, did not receive any.

Gardasil was shown to be highly effective in preventing pre-cancerous vulvar and vaginal lesions in the girls and women who tested negative for HPV 16 and 18 at the start of the trial. Of the girls and women who tested negative for HPV 16 and 18 at baseline, 19 in the control group developed pre-cancerous lesions compared with none in the Gardasil group).

Gardasil showed no benefit in participants who were already infected with HPV 16 and 18 when they started the trial, emphasizing the importance of becoming vaccinated before exposure.

The label information now shows that there is no evidence that Gardasil protects women after the age of 26, and neither does it protect against HPV types and related diseases not included in the vaccine.

No vaccine is 100 per cent effective, said the FDA, and Gardasil does not work if you are already infected when you become vaccinated. Thus all women should undergo regular Pap screening to detect precancerous lesions and increase the chances of successful treatment before the growths become cancerous.

Most adverse events reported to the FDA since Gardasil was approved in 2006 have not been serious, said the FDA. The most common events reported inclulde fainting, pain at the site of injection, headache, nausea and fever.

Source: FDA.

Written by: Catharine Paddock, PhD




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