Print

Email story

Comment

Email editor

Health and medicine

Vaccine blocks cervical cancer

The experimental treatment worked every time in a large study, and drug companies are racing to get it on the market.

TRENTON, N.J. - The first major study of an experimental vaccine to prevent cervical cancer found it was 100 percent effective in the short term at blocking the disease and lesions likely to turn cancerous, drug maker Merck & Co. said.

Gardasil, a genetically engineered vaccine, blocks infection with two of the 100-plus types of human papilloma virus, HPV 16 and 18. The two sexually transmitted viruses together cause about 70 percent of cervical cancers.

Other types of HPV also can cause cervical cancer and painful genital warts. About 20-million Americans have some form of HPV.

The final-stage study of Gardasil included 10,559 sexually active women ages 16 to 26 in the United States and 12 other countries who were not infected with HPV 16 or 18. Half got three vaccine doses over six months; half got dummy shots.

Among those still virus-free after six months, none who received the vaccine developed cervical cancer or precancerous lesions over an average two years of follow-up, compared with 21 who got dummy shots.

"To have 100 percent efficacy is something that you have very rarely," said Dr. Eliav Barr, Merck's head of clinical development for Gardasil. "We're breaking out the champagne."

The study, which was funded by Merck, was to be presented today at a meeting of the Infectious Diseases Society of America.

A second analysis, including hundreds more women participating in the ongoing study, showed that after just one dose the vaccine was 97 percent effective. That analysis found only one of the 5,736 women who got the vaccine developed cervical cancer or precancerous lesions, compared with 36 among the 5,766 who got dummy shots.

Barr said the 97 percent rate was more "real world," given that patients sometimes miss or delay follow-up shots or tests.

"I see this as a phenomenal breakthrough," said Dr. Gloria Bachmann, director of the Women's Health Institute at Robert Wood Johnson Medical School in New Brunswick, N.J.

Bachmann said diagnosis of infection leaves women anxious over the heightened risk of cervical cancer and raises questions among couples about infidelity and prior sexual activity.

"You have to get students in grammar school, middle school, high school (vaccinated) before they become sexually active," she said.

Cervical cancer is the second-most common cancer in women and their No. 2 cause of cancer deaths, resulting in about 3,000 deaths in the United States and nearly 300,000 around the world each year. At least half of sexually active men and women become infected with genital HPV at some point.

The immune system clears most such infections in a year or two, but several types of HPV can persist, cause cervical cancer or trigger other cancers in the genital area.

There is no cure for HPV, but the cancers can be treated and an improved Pap test is catching more cervical cancer before it has spread.

Merck, hammered by slumping revenues and profits and facing roughly 5,000 lawsuits over its withdrawn painkiller Vioxx, is seeking to beat rival drugmaker GlaxoSmithKline to market with the first cervical cancer vaccine.

GlaxoSmithKline did not return a call seeking comment, but has published research showing its vaccine against HPV 16 and 18 prevents persistent HPV infection. The Merck vaccine also reduces infection with HPV 6 and 11, which cause 90 percent of genital warts cases.

A Tampa researcher played a role in developing the vaccine. While she was at the University of Arizona, Anna Giuliano was principal investigator for the university's study of the vaccine. About 80 women participated in the study at Arizona, one of several sites around the world involved in seeing whether the vaccine would work.

Giuliano left Arizona in July 2004 to become program leader for the Risk Assessment, Detection and Intervention Program at H. Lee Moffitt Cancer Center & Research Institute.

She now is working on a $10-million federal grant to study how men spread the HPV virus.

"It's phenomenal. The potential is to prevent 70 percent of cervical cancers worldwide," Giuliano said Thursday. "As a cancer prevention person, this is the best news we've seen in a very long time." Merck plans by year's end to seek Food and Drug Administration approval to sell its vaccine for use by girls and young women.

"If all goes well, sometime in 2006 it should be on the market," Barr said.

Merck is continuing research on Gardasil and will soon report on four years of follow-up on women in the current study. The company also will explore whether the vaccine's effectiveness wanes over time. Barr said some women in the study developed dangerous precancerous lesions caused by HPV types other than 16 and 18.

Times staff writer Lisa Greene contributed to this report.

The second-most common cancer in women, after breast cancer.

Begins in the lining of the cervix, which is the lower part of the uterus.

The No. 2 cause of cancer deaths, after lung cancer; about 3,710 women will die from cervical cancer in the United States during 2005.

One of the few types of cancer where there are clear early stages that can be diagnosed and treated.

The most common symptoms are persistent vaginal discharge and abnormal vaginal bleeding.

Tends to occur in midlife; half of women diagnosed with cervical cancer are between the ages of 35 and 55.

Health care professionals recommend that women over age 20 have a cervical screen, or Pap test, at least every five years.

Sources: American Cancer Society; Association for International Cancer Research

[Last modified October 7, 2005, 01:51:07]