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.