Vaccine prevents genital warts as well as CIN.(News)

WASHINGTON -- A human papillomavirus vaccine developed by Merck & Co. is 100% effective in preventing genital warts in women in addition to preventing cervical cancer, Dr. John T. Schiller reported at the annual meeting of the Interscience Conference on Antimicrobial Agents and Chemotherapy.

The vaccine, known as Gardasil, includes HPV types 6, 11, 16, and 18. Types 16 and 18 account for about 70% of cervical cancer, and types 6 and 11 account for about 90% of genital warts, said Dr. Schiller, head of the neoplastic disease section of the National Cancer Institute, Bethesda, Md.

At 2 years of follow-up, Gardasil achieved 100% efficacy against genital warts, vulvar neoplasia, and vaginal neoplasia, in addition to the previously reported 100% efficacy against cervical intraepithelial neoplasia (CIN). The phase II Females United to Unilaterally Reduce Endo-Ectocervical Disease study (FUTURE I) included 2,717 women randomized to a vaccine group and 2,725 randomized to a placebo group. Overall, there were no cases of genital warts in the vaccine group vs. 40 cases in the placebo group.

Dr. Schiller also shared the latest findings from the FUTURE II study, a randomized, double-blind, phase III clinical trial that included about 12,000 women aged 18-25 years. The intent-to-treat numbers in the FUTURE II study showed extremely strong protection at 2 years of follow-up--only 2 cases of CIN grade 2 or 3--and the vaccine was well tolerated. One case of CIN was associated with HPV type 16, and the other with a combination of types 16 and 18. The phase III studies are ongoing, and the data remain under review, but findings similar to those from the phase II study are expected with regard to genital warts and vulvar and vaginal neoplasia.

Merck filed its Gardasil data with the Food and Drug Administration on Dec. 1, 2005, and a vaccine could be available in the United States by late summer in 2006, Dr. Schiller said. GlaxoSmithKline Inc. has stated that it will seek regulatory approval in 2006 for its vaccine, Cervarix, which immunizes against HPV 16 and 18, but that it might seek initial approval in Europe.

Once the vaccine becomes available, the top candidates for immunization will be 10- to 13-year-old girls. "They are the ideal first targets because presumably, they have not yet been exposed to ...