Biologic therapies for psoriasis

It is possible to suggest that the past two decades have led to greater advances in the treatment of extensive psoriasis than almost any other disease. The number of treatments available has grown tremendously and our treatment goals have changed radically. While at the turn of the century it was thought that complete clearance of psoriasis in patients who had extensive disease was not feasible in almost any patient, we now have medications that can attain complete clearance in up to 40 % of patients. With achievement of higher levels of response, a new understanding of the benefit of these responses to patients has identified a need for greater responses. The development of targeted biologic immunotherapy for psoriasis has historically relied on the understanding of the pathophysiology of disease. However, the targeted nature0 of these medications, in concert with fortuitous clinical observation, has furthered the understanding of the pathological mechanisms in psoriasis. In turn, new insight has led to even more effective treatments. Thus, the use and study of biologics improves disease treatment in two ways. Their targeted nature can promote individual health by helping to treat the patient's disease while their study leads to global benefit by directing the creation of newer treatments. In this chapter, we will examine how biologics have changed our understanding of psoriasis and has led to the development of a multitude of new and exciting treatments.