Adverse Reactions to Biologics in Psoriasis

Psoriasis is a chronic autoimmune disease which affects millions of people worldwide. Not only can psoriasis itself be debilitating and significantly reduce an individual's quality of life, but it is also a risk factor for other systemic disorders, such as metabolic syndrome, cardiovascular disease, and malignancy. Tremendous strides were made in the treatment of psoriasis during the mid-to-late-20th century, including the emergence of topical corticosteroids and vitamin D analogs, methotrexate, systemic retinoids, and phototherapy. However, it was not until 2004 with the advent of systemic biologic agents, which precisely target components of the immune system involved in the pathophysiological process of psoriasis, that the primary treatment benchmark increased from 50% improvement in the Psoriasis Area and Severity Index (PASI 50) to PASI 75, PASI 90, and even PASI 100, or complete resolution of cutaneous disease. Today, many patients receiving biologic therapy routinely experience greater than 75% or 90% reduction in cutaneous disease burden and a significant improvement in overall quality of life. These biologic agents are generally well-tolerated and safe but, like any medication, have associated adverse effects, some of which are predictable based on the effects of immune modulation, animal model studies, and human populations with known cytokine deficiencies. Going forward, it will be important to carefully monitor the safety profiles of these agents in both clinical trials and post-marketing surveillance registries to ensure long-term safety. It is reassuring that large safety registries are consistent in demonstrating an improved safety profile with newer and emerging biologic therapies.