May 17, 2006

Merck HPV vaccine seems effective, safe: FDA staff

WASHINGTON -- Merck & Co. Inc.'s experimental vaccine to prevent infection from a virus that causes cervical cancer appears to be effective, and studies did not raise major safety concerns, U.S. regulatory staff said in documents released on Wednesday.

The vaccine, Gardasil, was designed to prevent infection with certain types of the human papilloma virus, or HPV, which causes warts and most cases of cervical cancer -- the second biggest cancer killer in women. Some analysts project annual sales topping $2 billion if it wins approval.

Food and Drug Administration staff said they would ask an advisory panel that meets on Thursday to discuss the safety and effectiveness of Gardasil as well as findings that some women and girls who were infected with HPV before they got the vaccine had a higher rate of cervical lesions.

The FDA staff analysis said reviewers agreed with Merck's findings that Gardasil prevented early stage cervical cancer and pre-cancerous lesions in the overall group of women and girls studied. The evaluation of potential side effects in Merck studies "did not demonstrate a safety signal of concern," the FDA staff also said.

The two forms of sexually transmitted human papilloma virus, types 16 and 18, are responsible for an estimated 70 percent of cervical cancer cases and are the targets of Gardasil. Such cancers kill about 300,000 women worldwide each year, including almost 4,000 in the United States, Merck said.

Shares of Whitehouse Station, New Jersey-based Merck gained 32 cents, or 0.9 percent, to $35.44 in morning trading on the New York Stock Exchange.