Proteins by Design Antibody and protein biotherapeutics are changing the way physicians treat autoimmune diseases, asthma, and cancer. At Xencor, we apply proprietary protein engineering technologies to develop better biotherapeutics – antibodies that target new biological mechanisms and are more potent, safer and longer lasting – to improve patient outcomes and quality of life. Our XmAb antibody engineering technology dramatically augments natural antibody immune functions while maintaining over 99.5% identity to natural antibodies. This combination of new, highly potent activities while maintaining the beneficial drug features and simplicity of natural antibodies allows us to create differentiated drug candidates with potential for breakthrough performance. The XmAb® platform has resulted in a robust pipeline of antibody product candidates, including eight in human clinical trials being developed by Xencor and by pharmaceutical partners. Xencor is also discovering biologics products that improve the performance of old antibody drugs, known as biosuperiors, to benefit patients, ease compliance and help reduce costs.