Xencor Completes $45 Million Financing with MedImmune Ventures, Novo Nordisk and HealthCare Ventures Monrovia, CA – October 19, 2006 – Xencor, a company developing protein and antibody therapeutics, today announced that it raised $45 million in a private financing led by MedImmune Ventures, Inc.,

Xencor’s XmAb™ Technology Wins Wall Street Journal 2006 Technology Innovation Award MONROVIA, CA – September 11, 2006 – Xencor, Inc., a biotherapeutics company developing protein and antibody therapeutics, announced today that it has been named by The Wall Street Journal as a 2006 Wall Street

Xencor Completes $6 Million Bridge Financing with Novo Nordisk and Existing Investors Monrovia, CA – July 11, 2006 – Xencor, a biotherapeutics company developing protein and antibody therapeutics, today announced that it raised $6 million in a bridge financing from new investor Novo Nordisk and

Data Published in PNAS Show Engineering the Fc Region of Antibodies Makes Them More Toxic to Cancer Cells Monrovia, CA – March 7, 2006 – Engineering the “Fc“ region of monoclonal antibodies (mAbs) increases their toxicity to cancer cells, potentially improving the utility of targeted cancer

Xencor Licenses Immunofilter™ Technology to Centocor Research and Development, Inc. Monrovia, CA – February 14, 2006 – Xencor, Inc., a biotherapeutics company developing protein and antibody therapeutics, today announced that it has granted Centocor Research and Development, Inc.

Proprietary tool to assess potential protein immunogenicity for 95% of U.S. population.

Xencor and Roche Extend XmAb™ Antibody Therapeutics Collaboration Monrovia, CA – January 4, 2005 – Xencor, Inc., a biotherapeutics company developing protein and antibody therapeutics, today announced an extension to its research collaboration with Roche to create monoclonal antibodies with

MedImmune Licenses Xencor’s XmAb™ Technology To Create Antibody Therapeutics Against Select Tumor Targets; Fifth XmAb™ Deal For Xencor In The Last Year Monrovia, CA – December 7, 2005 – Xencor, Inc., a biotherapeutics company developing protein and antibody therapeutics, today announced that it has

Xencor Gives Panel Presentation and Company Update at BIO InvestorForum; Announces Recent Close of $20 Million in Financing MONROVIA, CA – October 18, 2005 – Xencor, Inc., a biotherapeutics company developing protein therapeutics and antibody drugs, announced today that Bassil Dahiyat, Ph.D.,

Xencor, Inc. Signs Collaboration with Centocor, Inc. to Improve Antibodies Xencor, Inc. licenses engineered Fc domains to Centocor, Inc. to enhance therapeutic efficacy Monrovia, CA – July 18, 2005 – Xencor, Inc., a biotherapeutics company developing protein therapeutics and antibody drugs, today