FDA Panel Backs Use of Gardasil as HPV Vaccine for Males
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Thursday, September 10, 2009
Federal health advisers say Merck's vaccine Gardasil, used to prevent cervical cancer in women, should also be approved to stop genital warts in men.
A Food and Drug Administration panel on Wednesday voted unanimously, with one abstention, that the vaccine is effective for blocking the human papilloma virus, or HPV, in males ages 9 to 26. The panel voted 7-1 that the vaccine is safe for those patients.
The FDA is not required to follow the panel's guidance, though it usually does.
HPV causes warts and certain rare cancers of the genitals in both men and women
While an approval decision could potentially double the market for Gardasil, analysts don't expect much use in males because genital warts usually clear up by themselves.
The health officials also said Wednesday that a long-delayed vaccine from GlaxoSmithKline successfully blocks the leading virus that causes cervical cancer in women.
The Food and Drug Administration's vaccine panel voted overwhelmingly that the vaccine Cervarix appears safe and effective for females ages 10 to 25.
If the FDA follows the panel's advice, Glaxo would begin competing against Merck's vaccine Gardasil, which has controlled the U.S. market since 2006.
London-based drugmaker Glaxo already has won approval for its vaccine in Europe, but its U.S. launch was delayed in 2007 when the FDA said it needed more data about the vaccine.
Panelists say newer studies suggest that the vaccine is safe, but they recommend follow-up studies to monitor miscarriages and inflammatory-muscular problems reported by a small number of patients.
The vaccine panel said it was unlikely that those problems were related to the vaccine, but said the issues should still be noted on the product labeling.
"This wasn't a pregnancy trial, and it wasn't meant to be used in pregnancy. It just happened accidentally," said Kenneth Noller, a doctor of obstetrics and gynecology at Tufts University. "I think this could be marketed with the usual caveat that it's not to be used in pregnancy."
HPV infects about 6 million people in the United States each year, and is mainly spread through sexual contact. It usually doesn't carry any symptoms and goes away within two years, but in rare cases it can develop into warts and cancers in both men and women.
Last year, nearly 4,000 women died of cervical cancer in the United States, less than 1 percent of all cancer-related deaths.
Even if the FDA grants approval, Glaxo will face an uphill battle against Merck's Gardasil, which has had the U.S. market to itself for the past three years. In addition to being an established brand, Gardasil also boasts an extra degree of protection against sexually transmitted diseases.
Gardasil and Cervarix both defend against HPV strains 16 and 18, which cause about 70 percent of cervical cancer cases. But Merck's vaccine also defends against two other HPV types that cause 90 percent of genital warts, something Cervarix does not target.
Leerink Swan analyst Seamus Fernandez estimates that Glaxo's Cervarix could eventually make up 25 to 30 percent of the total market for HPV-blocking vaccines. Cervarix global sales were $231 million last year.