A promising new vaccine against a pre-cancerous cervical virus

Nov 1 2005

Updated data from a study on a promising new vaccine against a pre-cancerous cervical virus shows superior efficacy in preventing cervical pre-cancers and non-invasive cervical cancer, according to a study presented during the American Association for Cancer Research's 4th Annual Frontiers in Cancer Prevention Research meeting in Baltimore.

Final results of the phase III study, originally published in early October, confirmed the vaccine's efficacy from available combined phase II and phase III data sets, incorporating an additional 7,000 patient records as compared to the interim results. The researchers concluded from these analyses that the administration of this vaccine, known as GARDASIL, is highly effective in preventing high-grade pre-cancerous illnesses and non-invasive cervical cancers.

Of the 8,487 women who received the vaccine, none were diagnosed with high-grade cervical pre-cancers (CIN 2/3+, cervical intraepithelial neoplasia) or non-invasive cervical cancers associated with human papillomavirus (HPV) types 16 and 18. Of the 8,460 women who did not receive the vaccine, 53 such cases were diagnosed.

In the larger population analysis, which included women who may have become infected with HPV during the vaccination period or who may have violated the protocol (e.g. by missing visits, etc.), the vaccine prevented 99 percent of HPV 16 or 18-related high-grade cervical pre-cancers (1 of 9,342 pts versus 81 of 9,400 in the placebo group) with an average follow up of 25 months.

The vaccine was generally well tolerated, and the most common adverse event reported in the trial was local discomfort at the injection site.

The study is part of an ongoing phase III program involving more than 25,000 people in 33 countries. For the FUTURE II study, a prospective, randomized, double-blind, placebo-controlled study, women aged 16 to 26 years were randomized to receive a three-dose regimen of either the vaccine or placebo at Day 1, Month 2, and Month 6. The analyses evaluated the incidence of cervical pre-cancers through follow up for an average of 20 months after completion of the regimen.

HPV, particularly types 16 and 18, is the primary cause of cervical cancers and other related illnesses, infecting more than 20 million Americans. Globally, cervical cancer is among the leading cancers in women, with an estimated 470,000 new cases every year, disproportionately within the developing world, and the availability of a vaccine to prevent the disease.