45. Is there potential for use of the quadrivalent HPV vaccine as a post-treatment adjuvant?

Abstract

Background: The quadrivalent HPV (qHPV) vaccine (Gardasil^®; Merck and Co., Whitehouse Station, NJ) is licensed to prevent anorectal HPV related disease in men and women through age 26 years. We demonstrated previously that qHPV was associated with decreased risk of recurrent HSIL among men who have sex with men (MSM; HR 0.50, 95% CI 0.26–0.98; P = 0.04). We endeavoured to determine if qHPV was effective in preventing condyloma development and recurrence in older MSM patients. Methods: A non-concurrent cohort study of patients vaccinated with qHPV compared with non-vaccinated patients. Those with a history of condyloma were disease free for 1 year. Results: 313 patients with a mean age of 42 years were followed for a median of 981 days. During 773.6 person-years follow-up, condyloma developed in 10 (8.6%) vaccinated patients (incidence 3.7 per 100 person-years) and 37 (18.8%) unvaccinated patients (incidence 7.3 per 100 person-years; P = 0.05). Multivariable hazards ratio showed that qHPV was associated with decreased risk of anal condyloma development (HR 0.45; 95% CI 0.22–0.92; P = 0.03). Kaplan–Meier (KM) survival analysis showed significantly reduced recurrence out to 4 years (cumulative incidence vaccinated 0.1 vs unvaccinated 0.25; P = 0.04). In the smaller subset of 103 patients with a history of condyloma, KM survival analysis showed striking separation of curves in the vaccinated vs unvaccinated with the cumulative incidence of recurrence (0.15, 0.35, respectively) but it did not reach significance (P = 0.12). Conclusions: The qHPV vaccine appears to prevent incident and recurrent condyloma in patients older than 26 years and might be a useful post treatment adjuvant.