ABSTRACT
Proteins and peptides have increasingly gained popularity as therapeutic agents since 1982, when human insulin was rst approved by the U.S. Food and Drug Administration (FDA). Using proteins as therapeutics is an obvious treatment, as many diseases are caused by mutations in the proteins (e.g., β-glucocerebrosidase, lactase, pancreatic enzymes) or by an excess or lack of them (e.g., insulin, growth hormone, blood clotting factors). To date, more than 130 proteins or peptides have been approved by the FDA as therapeutics,1 and more than 350 monoclonal antibodies, a class of protein therapeutics, are in various stages of preclinical and clinical development.2
