It is believed that imiquimod 5% cream has the potential to be an effective treatment for actinic keratoses. The purpose of this study is to evaluate the duration of the effect of topical imiquimod 5% topical cream for the treatment of actinic keratoses.

This study will assess the safety and efficacy of imiquimod 5% cream applied to actinic keratoses on the head to reduce the size of lesions. The objective is to analyze the effect of dose cycling with respect to the complete clearance rate when imiquimod 5% cream is applied 3 times per week for 4 weeks in 1 or 2 cycles. The complete clearance rate is defined as the proportion of subjects with no clinically visible AK lesions in the treatment area at the end of cycle 1 or the end of cycle 2.

Inclusion Criteria:

• At least 18 years of age.
• Have a total of 4 to 8 clinically typical, discrete, non-hyperkeratotic, non-hypertrophic AK lesions located within a contiguous 25 cm2 treatment area (balding scalp or face, but not both).
• Free of any significant findings (e.g. tattoos) in the potential application site area that may impair examination of treatment or surrounding area.
• Willing to eliminate tanning bed/sun parlor use for duration of study.

Exclusion Criteria:

• Evidence of clinically significant, unstable cardiovascular or immunosuppressive, hematologic, hepatic, neurologic, renal, endocrine, collagen-vascular, or gastrointestinal abnormalities or disease.
• Any dermatological disease and or condition in the treatment or surrounding area that may be exacerbated by treatment with imiquimod or cause difficulty with examination (e.g. rosacea, psoriasis, atopic dermatitis, eczema).
• Confirmed SCC, BCC anywhere on the head.
• Share a household where there is a person participating in a concurrent clinical study of imiquimod or being treated with imiquimod 5% topical cream.
• Active chemical dependency or alcoholism, as assessed by investigator.
• Females who are pregnant, breast-feeding or considering becoming pregnant while on the study.
• Females with childbearing unwilling to practice an effective method of contraception, as defined by the investigator for the duration of the study as well as one month after completion.
• Received any treatment, products or procedures within the designated time period prior to the prestudy visit as listed on page 4 of the protocol (Version 03 dd March 2003).