Xencor, Inc. is a biopharmaceutical company, which engages in the development of engineered monoclonal antibody therapeutics to treat severe and life-threatening diseases. Its proprietary technology platform, XmAb, is used to create next-generation antibody product candidates designed to treat autoimmune and allergic diseases, cancer, and other conditions. The company was founded by Bassil I. Dahiyat and Stephen L. Mayo in August 1997 and is headquartered in Monrovia, CA.