Cycle therapy of actinic keratoses of the face and scalp with 5% topical imiquimod cream: An open-label trial

Background: Preliminary studies indicate that topically applied immune response modifiers may be an effective and safe method of treating actinic keratoses (AKs). Objective. Our aim was to study the potential efficacy of topical 5% imiquimod cream in the treatment of facial or scalp AKs and improve the safety profile by using a novel "cycle" dosing regimen. Methods: This pilot study is an open-label trial that included 25 patients who had between 5 and 20 discrete AKs within a cosmetic unit of the forehead, scalp, or cheek. Treatment consisted of once-daily application of 5% imiquimod cream, 3 times a week for 4 weeks. to the entire cosmetic unit, followed by a rest period of 4 weeks. The cycle was repeated if any AKs remained after a complete 8-week cycle. A maximum of 3 cycles was permitted (24 weeks). Thirty-three sites in 25 patients were evaluated. Results: Compliance was excellent with a very tolerable safety profile. Complete clearing of all AKs was noted in 82% (27/33) of anatomic sites in 25 study subjects. Almost half the sites (15/33) were clear at the end of the first cycle. A "therapeutic interval" was noted during the rest period wherein clinical inflammation subsided but AKs continued to clear. An added effect was the uncovering and clinical appearance and subsequent eradication of incipient (subclinical) AKs in the treatment area. Conclusion: There was excellent compliance with the cycle therapy regimen. The observations and hypotheses made in this pilot study will be tested in controlled, randomized trials with larger study populations. The identification of a therapeutic interval may prove to be beneficial in formulating individualized dosing regimens.