Merck Cervical Cancer Vaccine Prevents Lesions

Whitehouse Station, N.J.-based Merck & Co. announced today that its experimental Gardasil vaccine completely prevented early-stage cervical cancer and precancerous cervical lesions caused by the two most common forms of human papillomavirus (HPV).

Gardasil targets HPV types 16 and 18, which are responsible for about 70 percent of cervical cancer cases. Merck said such cancers take the lives of about 300,000 women worldwide annually, including nearly 4,000 in the United States. The favorable findings were seen in Merck-sponsored Phase III trials of the vaccine.

The study, led by Laura Koutsky, a professor of epidemiology at the University of Washington, involved more than 12,000 women ages 16-26 from 13 countries who were not infected with either type 16 or 18 when the trial began. Over a six-month period, half the women received three doses of Gardasil, while the control group received placebos. Study follow-up was an average 17 months.

Gardasil was 100 percent effective in preventing precancerous lesions and early-stage cancers associated with HPV types 16 and 18 among participants who remained free of infection until they received their final vaccine dose, Merck reported. In contrast, the placebo group had 21 cases of lesions and early-stage cancers associated with the two HPV types.

While Gardasil gave the women "a high level of protection" against types 16 and 18, Koutsky said she hoped the vaccine would eventually be improved to protect against up to six more types of HPV that cause cervical cancer. "In that case, you could be blocking viruses that cause 87 percent of cervical cancer cases, instead of 70 percent," she said.

Merck plans to seek Food and Drug Administration approval for Gardasil, which also protects against two other types of HPV responsible for genital warts, later this year. In Europe, Merck is partnering its vaccine with Sanofi-Aventis.

Back to other news for October 6, 2005