Dosing with 5% imiquimod cream 3 times per week for the treatment of actinic keratosis: results of two phase 3, randomized, double-blind, parallel-group, vehicle-controlled trials.

OBJECTIVE To evaluate the efficacy and safety of 5% imiquimod cream compared with vehicle in the treatment of actinic keratosis (AK). DESIGN Two phase 3 randomized, double-blind, parallel-group, vehicle-controlled studies. SETTING Twenty-six ambulatory care offices, including dermatologists in private practice or research centers. PATIENTS Four hundred ninety-two patients, 18 years and older, with 4 to 8 AK lesions in a 25-cm(2) treatment area on the face or the balding scalp were randomized; an additional 162 patients underwent screening but were ineligible. INTERVENTIONS Patients applied 5% imiquimod (Aldara) or vehicle cream to the treatment area once daily, 3 times per week, for 16 weeks, followed by an 8-week posttreatment period. MAIN OUTCOME MEASUREMENTS Complete clearance rate (proportion of patients at the 8-week posttreatment visit with no clinically visible AK lesions in the treatment area), partial clearance rate (proportion of patients at the 8-week posttreatment visit with a >/=75% reduction in the number of baseline AK lesions in the treatment area), and frequency and severity of adverse events and local skin reactions were measured. RESULTS Complete and partial clearance rates for imiquimod-treated patients (48.3% and 64.0%, respectively) were clinically and statistically significantly higher than for vehicle-treated patients (7.2% and 13.6%, respectively). The median percentage reduction of baseline lesions was 86.6% for the imiquimod-treated group and 14.3% for the vehicle-treated group. CONCLUSION The 5% imiquimod cream dosed 3 times weekly for 16 weeks is safe and effective for the treatment of AK.