Objective: To assess the safety of imiquimod, an immune response modifier, in the topical treatment of external anogenital warts in HIV-infected patients.
Setting: Clinical sites in the United Kingdom (eight) and the United States (five).
Design: A prospective, randomized, double-blind, vehicle-controlled study of imiquimod 5% cream or vehicle applied for 8+/-2 h three times per week for a maximum of 16 weeks in HIV-seropositive males (n = 97) and females (n = 3) aged 18 years or more with clinically diagnosed external anogenital warts, CD4 T lymphocyte count of > or = 100 x 10(6) cells/l and Karnofsky score > or = 70.
Main outcome measures: Safety was assessed through the incidence and severity of local skin reactions and other adverse events, and through clinical laboratory tests. Wart clearance was documented by two-dimensional measurements of warts and by photography.
Results: Among the patients treated with imiquimod (n = 65) and vehicle (n = 35), the most common local skin reaction was erythema, (41.9 and 26.7%, respectively) and the incidence of patients reporting at least one adverse event was 69.2 and 65.7%, respectively. No clinically meaningful differences or changes in laboratory values were observed between treatment groups, nor were drug-related adverse effects observed in regard to HIV disease. While there was no significant difference between treatment groups in the number of patients who totally cleared their baseline warts (imiquimod 11% versus vehicle 6%, P = 0.488), more imiquimod-treated patients experienced a > or = 50% reduction in baseline wart area (38% versus 14%, P = 0.013).
Conclusion: Most local skin reactions were mild and no adverse effects on HIV disease were observed. Topically applied imiquimod 5% cream reduced wart area and may have clinical utility in treating external anogenital warts in some HIV-infected patients.