[Treatment of psoriasis using biologics]

Psoriasis is a chronic inflammatory skin disease, which is characterized by red, scaly, raised plaques. Its symptoms may range in severity and there are severe clinical subtypes of psoriasis including pustular psoriasis. Pre-biological systemic therapies were targeting mainly keratinocyte proliferation and T cell activation. However, there were cases, in which these classic therapies were not fully effective or could not be used because of the accompanied severe organ failure of the psoriasis patient. Recent progress in psoriasis research has clarified which of the cells, cell surface molecules and cytokines play a pivotal role in the pathogenesis of psoriasis. Biological systemic therapies targeting these molecules have turned out to be extremely effective in treating psoriasis and are now used to treat moderate to severe psoriasis worldwide. These biological therapies are not only more effective than pre-biological systemic therapies, but also show more rapid response, and long-term efficacy is expected. The TNF-alpha inhibitors are now approved as the first biological therapy for psoriasis in Japan. These TNF-alpha inhibitors are expected to be a new standard therapy for severe psoriasis, however, since the long-term safety is an unsolved issue, careful clinical monitoring is required. (193 words).