Xencor Renegotiates XmAb®5871 Agreement with Amgen; Regains All Rights and Plans Clinical Development in Rare Autoimmune Disease Focusing development on rare autoimmune disorder IgG4-related disease (IgG4-RD)Ongoing Phase 1b/2a clinical trial on track to report topline results by end of 2014Conference call today at 5:00 p.m. EDT

MONROVIA, Calif., Oct. 28, 2014 /PRNewswire/ -- Xencor, Inc. (NASDAQ: XNCR), a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of autoimmune diseases, asthma and allergic diseases, and cancer, today announced that it has regained all development and commercial rights to XmAb®5871 by seeking and obtaining a termination of the prior option and collaboration agreement and executing a new right-of-first-negotiation agreement with Amgen. XmAb5871 is a first-in-class monoclonal antibody containing Xencor's proprietary immune inhibitor XmAb Fc domain that targets FcγRIIb to inhibit B-cell function.  XmAb5871 is currently in...