Safety and Effectiveness Study of Actinic Keratosis Treatment Following Cryosurgery

In this multicenter, randomized, double-blind, placebo-controlled study, the efficacy and safety of imiquimod 3.75% cream following cryosurgery to treat clinically typical visible or palpable AK lesions on the face was compared with that of placebo cream. Based on a 1:1 randomization, approximately 120 subjects applied imiquimod 3.75% cream daily (up to 500 mg cream daily [18.75 mg imiquimod]) and approximately 120 subjects applied placebo cream daily during two 2-week periods (Cycle 1 and Cycle 2) separated by 2 weeks of no treatment. Subjects visited the clinic 9 times-1 screening/cryosurgery visit (additional visits might be needed during the screening period to assess healing from the cryosurgery), 4 treatment visits(treatment initiation at Weeks 0 and 4 and treatment follow-up at the end of Weeks 2 and 6), and 4 posttreatment visits (4, 8, 14, and 20 weeks after the last administration of study treatment at the end of Week 6). The total study duration for a subject, including a 2-week screening period, was up to 28 weeks.

Prior to cryosurgery, subjects had to have ≥10 clinically typical visible or palpable AK lesions in an area that exceeded 25 cm^2 on the face to be eligible for participation in the study. At screening, a minimum of 5 visible lesions were not treated with cryosurgery, and 5 to 14 visible lesions were treated with cryosurgery. Subjects had to have at least 5 AK lesions after the skin healed sufficiently from the cryosurgery to be eligible for randomization to either imiquimod 3.75% or placebo cream. Subjects applied up to 2 packets of study cream (500 mg total) as a thin layer to the entire face, avoiding the periocular areas, lips, and nares; ears were excluded from both assessment and treatment. Study cream was applied prior to normal sleeping hours and removed approximately 8 hours later with mild soap and water. Rest periods from daily treatment could be approved by the investigator as needed, with treatment resumption at the investigator's discretion.

Inclusion criteria

• In good general health
• Negative urine pregnancy test (for women of child-bearing potential) and agree to use an approved method of birth control while enrolled in the study.
• Prior to cryosurgery, have ≥ 10 clinically typical (visible or palpable) AKs in an area that exceeds 25 cm2 on the face.
• Must have had cryosurgery on 5 to 14 AKs on the face after giving informed consent and prior to receiving study medication. Lesions previously treated with cryosurgery must be healed sufficiently prior to randomization to study cream.
• Following cryosurgery, have ≥ 5 clinically typical (visible or palpable) AKs in an area that exceeds 25 cm2 on the face that are suitable for treatment with the study cream.

Exclusion criteria

• Women who are pregnant, lactating, or planning to become pregnant during the study
• Had a medical event within 90 days of the visit (e.g., stroke, heart attack, etc.).
• Have any skin condition in the treatment area that may be made worse by treatment with imiquimod (e.g., rosacea, psoriasis, atopic dermatitis, eczema).
• Have received specific treatments/medications in the treatment area within the designated time period prior to study treatment initiation