Merck vaccine wins OK for vaginal cancer

WASHINGTON (Reuters) - U.S. health regulators have approved Merck and Co's Gardasil vaccine to protect women against rare vaginal and vulvar cancers, the Food and Drug Administration said on Friday.

The vaccine is already available in the United States to prevent cervical cancer and genital warts in girls and women ages nine to 26 years old.

Gardasil was already approved for abnormal and precancerous vaginal and vulvar lesions, but the FDA said new evidence showed it benefited related cancers as well.

"There is now strong evidence showing that this vaccine can help prevent vulvar and vaginal cancers due to the same viruses for which it also helps protect against cervical cancer," said Jesse Goodman, director of the FDA's Center for Biologics Evaluation and Research.

The genetically engineered, or recombinant, vaccine is effective against four strains of the human papilloma virus, which is passed through sexual contact and causes genital warts and most cases of cervical cancer.

It also causes most, but not all, cases of vaginal and vulvar cancers, said Rick Haupt, head of Merck's clinical research program for Gardasil.

"With additional one-year follow-up, we now have more rigorous data," he said, adding clinical trials found the vaccine was 100 percent effective for the two rare cancers.

But the FDA, in a statement, cautioned that "no vaccine is 100 percent effective" and urged women to continue to receive routine screenings to detect possible cancer.

Common side effects from the vaccine include those seen with other injections such as fainting and injection pain as well as headache, nausea and fever, the FDA said.

Merck's Haupt also said the product's label was being updated to include additional reports of blood clots, autoimmune diseases and death in some patients who were given the vaccine.

Between 5,000 and 5,500 cases of vaginal and vulvar cancers are diagnosed in the United States each year, he said.

So far more than 18 million Gardasil doses have been distributed in the United States, Haupt said. Merck has said it expects the vaccine to reach between $1.4 billion and $1.6 billion in 2008 sales.