Future perspectives in the treatment of psoriasis

All available antipsoriatic therapies are of symptomatic character. Treatments established so far are limited in their use due to side effects or lack of efficacy resulting in poor quality of life for affected people. Development of new therapeutic approaches would not only broaden our armamentarium against psoriasis, but could also increase our understanding of the pathogenesis of this disease. In brief, 2 main targets represent attractive candidates, either the keratinocyte itself or the immune system. Promising therapeutic strategies include: (1) the search for new psoriasis susceptibility genes and their resulting phenotypes; (2) the interference with certain parts of cell signaling pathways that are involved in inflammatory processes; (3) the inhibition or elimination of activated T lymphocytes, e.g. by blocking of costimulatory signals or by deviation of a pathogenic immune response into a nonpathogenic one; (4) the blockade of proinflammatory cytokines; (5) the inhibition of leukocyte extravasation or trafficking; (6) the inhibition of angiogenesis. Some of these strategies are in phase 2 trials, others have already reached phase 3 status and are close to being approved by medicine agencies, and some are still visions of the future. This book chapter will give an overview of these new treatment strategies.