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

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. 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. 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 25cm 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. 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 <0.0001 versus vehicle). Both imiquimod 2.5% and 3.75% creams showed a positive effect on photodamage when compared with the vehicle cream.