Therapeutic response of basal cell carcinoma to the immune response modifier imiquimod 5% cream

Background: Basal cell carcinoma (BCC) responds to interferon therapy. Imiquimod is a cytokine and interferon inducer. Objective: This randomized, double-blind pilot trial evaluated the safety and efficacy of imiquimod 5% cream versus vehicle in the treatment of BCC. Methods: In this population of 35 patients with BCC, 24 received imiquimod 5% cream and 11 received vehicle cream in 1 of 5 dosing regimens for up to 16 weeks. Six weeks after treatment, an excisional biopsy of the target site was performed. Results: BCC cleared (on the basis of histologic examination) in all 15 patients (100%) dosed twice daily, once daily, and 3 times weekly; in 3 of 5 (60%) patients dosed twice weekly; 2 of 4 (50%) dosed once weekly; and in 1 of 11 (9%) treated with vehicle. Adverse events were predominantly local reactions at the target tumor site, with the incidence and severity of local skin reactions declining in groups dosed less frequently. Conclusion: Imiquimod 5% cream shows clinical efficacy in the treatment of BCC. (J Am Acad Dermatol 1999;41:1002-7.)