Treatment of external genital warts in men using 5% imiquimod cream applied three times a week, once daily, twice daily, or three times a day

BACKGROUND: Medical therapy for genital warts remains suboptimal. The topical interferon and cytokine inducer, imiquimod, has been proved effective for the treatment of external genital and perianal warts, but there is a substantial difference in the response rates between men and women. When 5% imiquimod cream is applied three times a week up to 16 weeks, approximately two thirds of women treated with imiquimod achieve complete clearance of genital warts, whereas only about one third of men clear completely. GOAL: This study was undertaken to determine whether more frequent application of topical imiquimod cream would improve the rate of genital wart clearance in men. STUDY DESIGN: A randomized treatment trial involving adult men with biopsy-proven genital warts was conducted at nine centers in the United States and Canada using four different application frequencies. RESULTS: Complete clearance rates during the 16-week treatment period were as follows for the different imiquimod treatment frequencies: three times a week (35 %), once daily (28 %), twice daily (24%), and three times a day (27%)(P = 0.88). The four treatment groups all showed comparable reductions in the total lesion area, with a median of more than a 90% reduction in the lesion area by the end of treatment. There was a significant increase in the incidence and severity of local skin reactions including erythema, vesicle formation, ulceration, and excoriation as the dosing frequency increased from three times a week to three times a day. CONCLUSIONS: In this study, the optimal dosage regimen was the approved three times a week regimen. More frequent application (up to three times a day) did not improve clearance and was associated with an increase in local adverse events.