Merck's HPV vaccine shines in Phase III efficacy trials

A vaccine to protect women from infection with human papillomavirus (HPV)—a virus that causes cervical cancer and genital warts—was found to be 100% effective at preventing pre-cancerous lesions associated with the strains of the virus that are contained in the vaccine. This is the first report from a large-scale efficacy trial with Merck's HPV vaccine, known as Gardasil.

In this Phase III trial (FUTURE II) 12,167 women aged 16-26 were inoculated at 90 sites in Brazil, Colombia, Denmark, Finland, Iceland, Mexico, Norway, Peru, Poland, Singapore, Sweden, the UK, and the US. Women in the trial received up to three injections. Gardasil is a virus-like particle (VLP) vaccine consisting of a single HPV protein that self-assembles into an empty shell and closely resembles a virus particle. Proteins from 4 strains of HPV are included; strains16 and 18 are responsible for over 70% of cervical cancer cases worldwide, while 6 and 11 cause more than 90% of genital warts. The vaccine can not cause HPV infection because the whole virus is not included in the vaccine.

Merck is now in the process of preparing its application to the US Food and Drug Administration for approval and licensure to market and sell the first cervical cancer vaccine. Cervical cancer is one of the leading cancers among women and there are more than 290,000 mortalities associated with it annually. Many of these deaths occur in developing countries where there are few screening programs to provide women with regular Pap tests that can detect cervical lesions caused by the virus.

"Where the vaccine is really needed is in developing countries," says Jessica Kahn, of the Cincinnati Children's Hospital. "It could have a tremendous impact there on mortality rates." Another HPV vaccine, developed by GlaxoSmithKline Biologicals in Rixsensart, Belgium is also in Phase III clinical trials.

All articles written by Kristen Jill Kresge