Monoclonal antibodies (mAbs) have become increasingly important as innovative therapeutic
agents during the past two decades. Interest by biopharmaceutical fi rms in developing
these products has been driven by critical advances in the engineering, design and
manufacturing of mAbs, as well as improved understanding of target biology and antibody
mechanisms of action. As of 2012, the rate at which new mAb product candidates enter
clinical study has risen to ~60 per year, a total of ~350 mAbs are undergoing evaluation in
clinical studies, over 30 mAbs have been approved in either the United States or European
Union, and annual global sales of mAb therapeutics total nearly $60 billion.