Merck HPV vaccine candidate effective against multiple strains of the virus

An experimental vaccine has been shown to be effective in preventing infection with four of the most common strains of human papillomavirus (HPV) in 90% of women who were part of a recent clinical trial. HPV is a sexually transmitted disease that causes genital warts and can lead to cervical cancer in women. Cervical cancer is responsible for 250,000 deaths among women each year and is especially deadly in the developing world where women are not regularly screened for this type of cancer.

This vaccine candidate, developed by US-based Merck & Co., is made from a virus-like particle that cannot cause an infection and offers protection against the four strains of the virus that are most likely to cause cancer. Previous candidates from Merck were only effective against a single strain of the virus. In the trial 277 women received three injections with the vaccine candidate, known as Gardasil. These women were compared with a control group of 275 volunteers who received a placebo, or an inactive vaccine. All women in the study were between the ages of 16 and 23. Over the course of the three-year trial, 36 women in the placebo group experienced an HPV infection compared to only 1 in the vaccine group.

The company plans to approach the US Food and Drug Administration later this year for approval of the vaccine candidate, after collecting results from a larger clinical trial. Gardasil is one of two HPV vaccines in late stage testing. GlaxoSmithKline in the UK and MedImmune in the US are developing the other candidate. This vaccine showed similar results in clinical trials against two strains of HPV.

All articles written by Kristen Jill Kresge