A federal health panel says evidence supports expanding use of Merck's Gardasil vaccine to prevent anal cancer in young men and women.
The panel of Food and Drug Administration advisers said a 4,000-patient study conducted by Merck & Co. Inc. shows the vaccine lowers the risk of anal cancer in men. They said these results can also be applied to women.
Anal cancer is relatively rare, affecting about 5,000 people in the U.S. each year.
Gardasil, Merck's top-selling vaccine, already is approved for prevention of cervical cancer and genital warts in girls and women aged 9 to 26. It's also approved for preventing genital warts in boys and men aged 9 to 26.
The vaccine works by blocking four of the most common strains of human papilloma virus, or HPV.