Abstract: Objective To evaluate the efficacy and safety of imiquimod 5% cream(Aldara)in the treatment of external anogenital warts.Methods A seven-centre,randomized,double-blinded,paral-lel-controlled study was conducted.Patients were randomly assigned either to imiquimod group,beginning with imiquimod treatment for 16 weeks followed by 4 weeks of vehicle control,or to vehicle control group, treated initially with vehicle for 4 weeks followed by 16 weeks of imiquimod.Imiquimod was applied at night 3 times a week,with a minimum retention period of 8 hours for every time.All patients were clinically evaluated every 4 weeks.Patients could stop treatment at any time if there was complete resolution of base-line warts during the 20-week treatment period.The primary outcome measure was partial clearance(defined as a reduction of≥50% of baseline wart count)rate.Secondary outcome measure included complete clear-ance(defined as a complete elimination of baseline warts)rate and reduction rate of baseline wart count or size.Results A total of 144 patients were enrolled in this study.At the end of the study,the partial clear-ance rate was 75.0%(108/144)in intension to treat(ITT)population,and 83.5%(106/127)in per protocol(PP)population.The complete clearance rate was 79.9%(115/144)and 89.8%(114/127)in ITT and PP population,respectively.At 4 weeks,significant difference was found between the imiquimod and vehicle groups in the partial clearance rates[48.6%(35/72)vs 19.4%(14/72),P=0.0004]and complete clearance rates[22.2%(16/72)vs 6.9%(5/72),P=0.009].The most common adverse event was application site reactions,which were generally mild to moderate.No severe side effects were observed. Conclusions The efficacy of imiquimod 5% cream is superior to that of vehicle in the treatment of exter-nal anogenital warts,and the 16-week treatment strategy,at a frequency of 3 times a week,is effective,safe, and convenient.

Key words: Warts, Genitalia, Imiquimod, Randomized controlled trials