XmAb^® Antibody Therapeutics

Antibodies direct the immune system to a specific molecular target in the body, and because they are so specific, offer an improved safety margin over existing small molecule treatments for cancer and other diseases. XmAb® technology engineers antibody drugs to manipulate their recruitment of the immune system, for example, to heighten the immune attack on a target, or to down-regulate immune cells in the case of autoimmune disease. Several blockbuster antibody therapies are enabling physicians to make important strides in the treatment of rheumatoid arthritis, lymphoma and leukemia, colon and breast cancer, and more than 200 new antibodies are currently under development for an even broader range of diseases.

Unfortunately, a large fraction of cancer patients have tumors that fail to respond to antibody drugs, and many inflammatory diseases are resistant to current therapies. Xencor has applied our XmAb® high ADCC (Antibody Dependent Cell Cytotoxicity), XmAb® Xtend™ and XmAb® γRIIb (CD32b) technologies to develop a portfolio of unique next-generation antibody candidates with significantly improved potency, novel mechanisms of action, and/or longer duration of action to improve dosing convenience and patient outcomes. Our first antibody candidate, XmAb®2513, completed a Phase 1 clinical trial for Hodgkin’s lymphoma and T cell lymphomas, and targets CD30 for high ADCC, an antigen expressed in various hematologic malignancies. XmAb®5574 (MOR208), our antibody that targets CD19 for high ADCC, has been partnered with MorphoSys and will enter Phase 1 clinical development in patients with chronic lymphocytic leukemia (CLL). We plan on starting clinical testing of our first autoimmune disease therapy, XmAb®5871, in 2011. We also have several antibody candidates in preclinical development including XmAb®5592, and XmAb®7195 for myeloma and asthma, respectively.

In addition to developing a rich internal pipeline of antibody drug candidates, Xencor partners with multinational pharmaceutical and biotechnology companies like Boehringer Ingelheim, Centocor, Human Genome Sciences and Pfizer to leverage its antibody engineering technologies to design next-generation antibody drugs, and companies like MorphoSys for co-development of its proprietary products. We work with our partners to improve the pharmacological properties of monoclonal antibodies by applying our Xtend™ technology for half-life extension, high ADCC technology for enhanced potency or γRIIb (CD32b) technology for immuno-modulation. In our XmAb partnership agreements, Xencor has received upfront payments and is eligible to receive milestones and royalties based on successful commercialization of antibody products.