Combination Therapy With 5-Fluorouracil and Photodynamic Therapy in Post-transplant Premalignant Skin Disease

This randomized, intra-patient comparative study is designed to investigate the combination regimen of 5-fluorouracil cream (5FU) and Photodynamic Therapy (PDT), versus PDT alone, for its ability to generate significantly elevated levels of the target photosensitizer, protoporphyrin IX (PpIX), in lesions of actinic keratoses (AKs) and to more effectively treat and prevent recurrence of AKs. The target population comprises patients with solid organ transplants (renal, hepatic), as well as normal (immunocompetent) subjects to control for possible influences of immunosuppression.