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If we’re soon able to vaccinate boys and men against HPV, can we afford to?

An FDA panel has recommended that use of the approved HPV vaccine be extended to males to prevent genital warts. The recommendation addresses safety and efficacy, but not cost-effectiveness.

October 2009 · Vol. 21, No. 10

The quadrivalent vaccine against human papillomavirus (HPV), approved for use in females several years ago to prevent cervical cancer, appears set to get the nod from the FDA for prevention of genital warts in boys and men. A key panel—the Vaccines and Related Biological Products Advisory Committee—voted in September to extend use of the vaccine (Gardasil; Merck) to males 9 to 26 years old.

The FDA usually follows the recommendations of its advisory committees.

The committee reviewed data on more than 5,000 males 9 to 26 years old in the United States and other countries. Subjects in trials were randomized to receive the three-shot series of Gardasil or placebo over 6 months.

Overall, the vaccine was 90% effective against genital warts in males who had no evidence of prior exposure to the four HPV types in the vaccine (HPV 6,11,16,18).

Hope is that the vaccine will prevent diseases and conditions beyond genital warts, including HPV-associated laryngeal papillomatosis, head and neck cancers, and penile and anal malignancies. Additionally, because it is likely that not all females will receive the vaccine, providing HPV vaccination for males will reduce risks for females as well—what’s called “herd immunity.”

Concerns raised about safety and efficacy

At a hearing that preceded the advisory committee’s vote, attendees raised a number of concerns about the vaccine’s safety and efficacy. Some argued that a recommendation and approval for the male population are premature.

J. Thomas Cox, MD, Director of the Women’s Clinic at the University of California, Santa Barbara, and past-President of the American Society for Colposcopy and Cervical Pathology, believes such worries are unfounded. He asserts that the recommendation to approve Gardasil for males was based on impressive safety and efficacy data in both males and females—although, he acknowledges, there are limitations to that data (as there always are for new vaccines), which reflect 2 to 3 years of study in males and 5 years in females.

Cox also serves on the data and safety monitoring board for Gardasil.

“Based on safety and efficacy data, I don’t think it was premature” to approve the vaccine for males, Cox told OBG Management. “I think the real debate in this country regarding immunization of males will not be about safety and efficacy,” he adds, noting that the most recent CDC review of VAERS reports following more than 23 million doses of Gardasil stated that “The postlicensure safety profile presented here is broadly consistent with safety data from prelicensure trials”1 which had demonstrated the vaccine to be very safe.”

The only concern raised in that study was disproportional reporting of syncope and venous thromboembolic events (VTE) among females, Cox says. While most of the women having VTE had other risk factors for these events, this is the one “signal” detected that will be closely watched.

The critical issue really is cost

The focus of the debate over the use of HPV vaccine in males, Cox says, should be “what we can afford to cover.”

Although the vaccine appears to be cost-effective in females to the age of about 18 years, it remains unclear whether it will prove to be so in males and older women, Cox says. He cites a recent article in Vaccine, which theorized that, if a “reasonable” level of HPV vaccination of girls can be achieved, vaccinating boys is unlikely to be cost-effective.2

However, Cox also says that vaccination of only one gender has not, in the past, proved successful at reducing disease levels without enough of the opposite gender also being vaccinated—measles being a good example. Vaccinating both males and females may therefore be necessary to obtain the desired level of protection for the population, and that necessity may change cost-effectiveness projections.

“With momentum building for comprehensive health-care reform,” says Cox, “cost-effectiveness is going to have to be looked at in everything we do.”

“Will society want to pay for what isn’t cost-effective?” he asks. “That’s the big debate for the future.”

References

1. Slade BA, Leidel L, Vellozzi V, et al. Postlicensure safety surveillance for quadrivalent human papillomavirus recombinant vaccine. JAMA. 2009;302:750-757.

2. Kim JJ, Brisson M, Edmunds WJ, Goldie SJ. Modeling cervical cancer prevention in developed countries. Vaccine. 2008;26 Suppl 10:K76-86.

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