Imiquimod 2.5% and 3.75% for the treatment of actinic keratoses: Results of two placebo-controlled studies of daily application to the face and balding scalp for two 3-week cycles
Accepted 3 June 2009. published online 04 February 2010.
Background
Imiquimod 5% cream is approved as a 16-week regimen for the treatment of actinic keratoses involving a 25-cm2 area of skin.
Objective
We sought to evaluate imiquimod 2.5% and 3.75% creams for short-course treatment of the entire face and scalp.
Methods
In two identical studies, adults with 5 to 20 lesions were randomized to placebo, or imiquimod 2.5% or 3.75% cream (1:1:1). Up to two packets (250 mg each) were applied per dose once daily for two 3-week treatment cycles, with a 3-week, no-treatment interval. Efficacy was assessed at 8 weeks posttreatment.
Results
In all, 490 subjects were randomized to placebo, or imiquimod 2.5% or 3.75% cream. Median baseline lesion counts for the treatment groups were 9 to 10. Complete and partial clearance rates were 5.5% and 12.8% for placebo, 25.0% and 42.7% for imiquimod 2.5%, and 34.0% and 53.7% for imiquimod 3.75% (P < .001, each imiquimod vs placebo; P = .034, 3.75% vs 2.5% for partial clearance). Median reductions from baseline in lesion count were 23.6%, 66.7%, and 80.0% for the placebo, imiquimod 2.5%, and imiquimod 3.75% groups, respectively (P < .001 each imiquimod vs placebo). There were few treatment-related discontinuations. Temporary treatment interruption (rest) rates were 0%, 17.1%, and 27.2% for the placebo, imiquimod 2.5%, and imiquimod 3.75%, respectively.
Limitations
Local effects of imiquimod, including erythema, may have led to investigator and subject bias.
Conclusions
Both imiquimod 2.5% and 3.75% creams were more effective than placebo and had an acceptable safety profile when administered daily as a 3-week on/off/on regimen.
eDepartment of Dermatology, Baylor College of Medicine, Houston, Texas
Reprint requests: C. William Hanke, MD, Laser and Skin Surgery Center of Indiana, 13400 N Meridian St, Suite 290, Carmel IN 46032.
Supported by Graceway Pharmaceuticals LLC.
Disclosure: Drs Hanke and Beer were investigators and consultants for Graceway and received compensation for services. Drs Stockfleth and Rosen were consultants for Graceway and received compensation for services. Drs Wu and Levy are employees of Graceway.
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