Cervical Cancer Vaccine Close to FDA Approval

On Thursday, an advisory panel of the Food and Drug Administration recommended approval of Merck & Co.'s vaccine against the four types of the STD human papillomavirus (HPV) responsible for a majority of cervical cancer and genital wart cases. As FDA usually follows recommendations made by its advisory panels, approval of Gardasil is likely, said public health experts. The agency is expected to decide by June 8.

HPV is the world's most common STD, infecting up to 80 percent of women by the time they reach age 50, although only a small fraction of persistent infections ever develop into cervical cancer. In a large clinical trial focused on females ages 9-26, Gardasil was 100 percent effective in preventing infection from two HPV strains that cause 70 percent of cervical cancer cases. The vaccine was 99 percent effective against two more strains that cause 90 percent of genital wart cases.

Gardasil is given in three injections over six months and will cost $300-$500. Public health experts worry that cost will be prohibitive for millions worldwide, especially in developing countries where cervical cancer is deadliest. Merck said it is working with the Bill & Melinda Gates Foundation on ways to get the vaccine to poor countries.

And while doctors lauded the FDA panel's recommendation, several noted it remains unclear how long Gardasil protects women and whether boosters will be needed to maintain efficacy. Physicians were also concerned Gardasil would incorrectly be seen as a replacement for annual Pap smears. Checkups are still needed because the vaccine does not protect against all HPV strains and because there are other types of cancer that can only be detected via regular gynecological exams, they advised.

Gardasil is not the first vaccine to protect against cancer: The hepatitis B vaccine prevents the virus that causes liver cancer.

Back to other news for May 19, 2006