Reduction in lesions from Lmax: a new concept for assessing efficacy of field-directed therapy for actinic keratosis. Results with imiquimod 3.75%

Background Current parameters for assessing the efficacy of actinic keratosis (AK) treatments compare clinical lesions at the start and end of a study. However, the sun-exposed field also contains subclinical lesions which may become detectable during treatment. Lmax, the maximum lesion count during treatment, is a new concept to better assess the efficacy of field-directed AK therapies. Measuring efficacy using the reduction in lesions from Lmax includes for the first time the clearance of both subclinical and clinical lesions.