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

J Am Acad Dermatol. 2010 Apr;62(4):582-90. doi: 10.1016/j.jaad.2009.07.004. Epub 2010 Feb 4.

Abstract

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 (> or =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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage*
  • Administration, Topical
  • Adult
  • Aged
  • Aged, 80 and over
  • Aminoquinolines / administration & dosage*
  • Dosage Forms
  • Double-Blind Method
  • Drug Administration Schedule
  • Face
  • Female
  • Humans
  • Imiquimod
  • Keratosis, Actinic / drug therapy*
  • Male
  • Middle Aged
  • Scalp
  • Time Factors

Substances

  • Adjuvants, Immunologic
  • Aminoquinolines
  • Dosage Forms
  • Imiquimod