The ability of antibodies to bind to their targets specifically and with high affinity make them attractive therapeutic reagents for use in the treatment of many human diseases. In fact, a number of antibodies have recently reached the market place, and approximately 25% of the current biopharmaceuticals in phase III trials are antibodies. Abgenix has developed a proprietary technology to produce fully human antibodies. In order to enhance the utility of fully human monoclonal antibodies as therapeutic agents, this proposal specifically aims to develop a method to increase the serum half-life of antibodies. Antibodies will be engineered to have an increased affinity for the receptor that rescues IgG antibodies from serum catabolism (Fc protection receptor, FcRp). Higher affinities to FcRp will allow the modified antibodies to out compete normal IgG for binding to the receptor. As a result, these modified antibodies will be preferentially rescued from catabolism and will have an extended serum half-life. The ability to prolong the serum half-life of antibodies will potentially reduce the costs of therapy by directly reducing the number of doses that may be required for treatment. PROPOSED COMMERCIAL APPLICATIONS: A monoclonal antibody with an increased serum half-life will reduce the number of doses required for therapy. This will directly result in lower amounts of antibody being required per treatment and as a result a reduction in the cost of goods per therapy. Fewer doses would also increase the quality of life of patients and improve patient compliance making the product more marketable. Abgenix, will initially market this technology to its corporate partners and intends to incorporate the technology in the development of its own products