Source: money.cnn.com
Author: Peter Loftus

A new study suggests Merck & Co.’s (MRK) Gardasil vaccine, which is primarily given to prevent cervical cancer in girls and women, may also be effective in preventing genital warts and penile cancer when given to males.

Merck hopes the company-funded study will support roughly doubling the target population for the vaccine, which could help jump-start sagging sales. The Whitehouse Station, N.J., company said it remains on track to apply by year end for Food and Drug Administration approval to market Gardasil to boys and men ages 9 to 26 for prevention of external genital lesions caused by certain viral strains.

“This is groundbreaking data,” said Anna Giuliano, professor of medicine and epidemiology at University of South Florida, who co-authored the study. “To demonstrate that Gardasil prevents infection and disease at a very high level in males – that’s the other half of the world.” It was the first study to demonstrate Gardasil’s effectiveness in males – prior studies had shown it could produce a positive immune response in males.

The vaccine, which was launched in 2006, is currently approved in the U.S. for girls and women ages 9 through 26 to prevent cervical, vulvar and vaginal cancers, as well as genital warts and other lesions caused by certain viral strains.

These diseases, in both males and females, share the same cause: Human papillomavirus, or HPV, which is transmitted through sexual contact. The cancers in men caused by HPV, however, are rarer than cervical cancer. Gardasil targets four types of HPV that are believed to cause many of the cases of these cancers and lesions. Gardasil is injected in three doses over six months, and costs about $360 in total.

After strong sales growth following its 2006 launch, Gardasil sales have slowed this year, partly because women ages 19 to 26 haven’t been as eager to get vaccinated as Merck had hoped. The vaccine also has been dogged by concerns about its safety, though federal health authorities recently concluded it was relatively safe. Gardasil sales fell 2% to $1.1 billion for the first nine months of the year.

One recent effort by Merck to expand the vaccine’s target population failed. In June, the FDA declined to approve Merck’s application to market Gardasil to women ages 27 through 45.

The new study in males is to be presented Thursday at a medical conference in Nice, France.

The study evaluated about 3,400 men aged 16 to 26 years old who had no signs of lesions at the start of the study. About half were given Gardasil and half were given a fake vaccine, or placebo. The study tracked rates of both genital warts and lesions on or near the penis that are considered potentially precancerous. The study included both heterosexual and homosexual males.

After nearly 30 months of follow-up, there were three cases of such external lesions in the vaccine group, versus 31 cases in the placebo group, for an efficacy rate of about 90.4%, Merck said. Most of the cases were genital warts.

No vaccine-related serious adverse events were reported in the study. A slightly higher proportion of vaccine recipients had injection-site adverse events versus placebo, or 60.1% versus 53.7%. The study is ongoing.

According to the Centers for Disease Control and Prevention, about 1% of sexually active men in the U.S. have genital warts at any one time. Penile cancer is rare, especially in circumcised men, affecting about one in every 100, 000 men in total. HPV also is believed to cause certain oral cancers, but the new Merck study didn’t evaluate Gardasil’s effect on oral cancer.

GlaxoSmithKline PLC (GKS) sells a competing HPV vaccine called Cervarix, which isn’t yet approved in the U.S.