Old and New Biological Therapies for Psoriasis

Biological therapy became available for psoriasis with the introduction of alefacept at the beginning of this century. Up to then, systemic treatment options comprised small molecule drugs, targeting the immune system in a non-specific manner. The first biologics targeted T-cell activation and migration and served as an alternative to small molecules. However, significant improvement in outcome was first accomplished with the introduction of tumor necrosis factor-α inhibitors that were already approved for other inflammatory disorders, including rheumatic diseases. Along with the progress in understanding psoriasis pathogenesis, highly targeted and effective therapies have since developed with the perspective not only to improve but to clear psoriasis. These accomplishments enable future achievement of advanced goals to individualize treatment best suited for each patient. Mechanistic studies with patients treated with the new highly targeted biologics may guide us towards these goals. This review offers an overview of biologics developed for psoriasis and illustrate a historical progress in the treatment of this common chronic inflammatory skin condition.