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.