Safety and Effectiveness Study of Imiquimod Creams for Treatment of Actinic Keratoses (AKs)

This was a randomized, double-blind, multicenter, placebo-controlled study that compared the efficacy and safety of 2.5% imiquimod cream and 3.75% imiquimod cream with that of placebo in the treatment of typical visible or palpable AKs of the face or balding scalp. Subjects were scheduled for a total of 9 visits (1 prestudy screening visit and 8 on-study visits). Subjects determined to be eligible during the screening phase were randomized in a 1:1:1 ratio to 2.5% imiquimod cream, 3.75% imiquimod cream, or placebo cream. The creams were applied daily for 2 treatment cycles. The first treatment cycle consisted of 2 weeks of daily treatment followed by 2 weeks of no treatment, and the second treatment cycle consisted of an additional 2 weeks of daily treatment followed by 8 weeks of no treatment. The investigator selected the treatment area for the study (either the entire face or the entire balding scalp, but not both). Subjects applied a thin layer of cream to the treatment area (up to 2 packets, or 500 mg of product, per application), avoiding the periocular areas, lips, and nares. Study medication was applied prior to normal sleeping hours and removed approximately 8 hours later with mild soap and water. Ears were excluded from both assessment and treatment. Rest periods from daily treatment were instituted by the investigator as needed to manage local skin reactions (LSRs) or application site reactions, with resumption of treatment upon adequate resolution as determined by the investigator. The duration of each subject's study participation was approximately 18 weeks, including a 4-week maximum screening period and a 14-week study period.