Imiquimod 2.5% and 3.75% Cream for the Treatment of Photodamage: A Meta-analysis of Efficacy and Tolerability in 969 Randomized Patients.

Background: Ad-hoc reports within clinical studies of imiquimod for the treatment of actinic keratosis (AK) have suggested the drug can improve both skin texture and overall signs of photodamage. Objective: We sought to assess the efficacy and tolerability of imiquimod 3.75% and 2.5% cream for the treatment of photodamage in patients with AK of the full face or balding scalp. Methods: A meta-analysis of four identical multicenter, randomized, double-blind, vehicle-controlled studies was conducted. The studies included a total of 969 adult subjects (aged 33-91 years) with 5 to 20 visible lesions or palpable AKs in an area exceeding 25cm2 on either the face or balding scalp. Patients were randomized to imiquimod 3.75%, imiquimod 2.5%, or vehicle cream (1:1:1). Up to two packets (250mg each) were applied per dose once daily for two two-week treatment cycles, separated by a two-week no-treatment interval. Photodamage improvement was assessed at study end based on subjects' baseline assessments using a seven-point scale. Local skin reactions were recorded throughout the study. Results: Combined Investigator's Global Integrated Photodamage (IGIP) score was "significantly" or "much" improved in 57.6 percent (n=175) of patients treated with imiquimod 2.5% cream and in 69.6 percent (n=208) of patients treated with imiquimod 3.75% cream versus in 25.7 percent (n=76) of patients treated with the vehicle. Mean IGIP scores at end of study were 1.67, 1.98, and 0.73, respectively (both actives P <0.0001 versus vehicle). Conclusion: Both imiquimod 2.5% and 3.75% creams showed a positive effect on photodamage when compared with the vehicle cream.