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 2-week cycles
Accepted 1 July 2009. published online 04 February 2010.
Background
The approved imiquimod 5% cream regimen for treating actinic keratoses requires a long treatment time and is limited to a small area of skin.
Objective
We sought to evaluate imiquimod 2.5% and 3.75% for short-course treatment of the full face or balding scalp.
Methods
In two identical studies, adults with 5 to 20 lesions were randomized to placebo, imiquimod 2.5%, or imiquimod 3.75% (1:1:1). Up to two packets (250 mg each) were applied per dose once daily for two 2-week treatment cycles, with a 2-week, no-treatment interval between cycles. Efficacy was assessed at 8 weeks posttreatment.
Results
A total of 479 patients were randomized to placebo, or imiquimod 2.5% or 3.75%. Complete and partial clearance (≥75% lesion reduction) rates were 6.3% and 22.6% for placebo, 30.6% and 48.1% for imiquimod 2.5%, and 35.6% and 59.4% for imiquimod 3.75%, respectively (P < .001 vs placebo, each; P = .047, 3.75% vs 2.5% for partial clearance). Median reductions from baseline in lesion counts were 25.0% for placebo, 71.8% for imiquimod 2.5%, and 81.8% for imiquimod 3.75% (P < .001, each active vs placebo; P = .048 3.75% vs 2.5%). There were few treatment-related discontinuations. Patient rest period rates were 0% for placebo, 6.9% for imiquimod 2.5%, and 10.6% for imiquimod 3.75%.
Limitations
Local pharmacologic effects of imiquimod, including erythema, may have limited concealment of treatment assignment in some patients.
Conclusions
Both imiquimod 2.5% and 3.75% creams were more effective than placebo and were well tolerated when administered daily as a 2-week on/off/on regimen to treat actinic keratoses.
eDepartment of Dermatology, New York University Medical School, New York, New York
Reprint requests: Neil Swanson, MD, Department of Dermatology, Oregon Health and Science University, Center for Health and Healing, 3303 SW Bond Ave, Portland, OR 97239.
Funding sources: Graceway Pharmaceuticals LLC.
Disclosure: Dr Swanson was an investigator and consultant for Graceway, and has received compensation for services. Dr Abramovits was an investigator and speaker for Graceway and has received compensation for services. Dr Berman was an advisory board member and speaker for Graceway and has received compensation for services. Mr Kulp and Dr Levy are employees of Graceway. Dr Rigel was a consultant, advisory board member, and investigator for Graceway and has received compensation for services.
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