Background
CD20-directed therapy is well established in oncology, and was recently demonstrated to be highly effective in the treatment of rheumatoid arthritis (RA) [1]. Small modular immunopharmaceutical drugs are smaller than antibodies yet are capable of utilizing effector functions of antibody-dependent cellular cytotoxicity, complement-mediated cytotoxicity and apoptotic signaling. TRU-015 is a small modular immunopharmaceutical drug candidate that is specific for CD20. TRU-015 has been demonstrated to effectively deplete B lymphocytes in cynomolgus monkeys in a dose-dependent manner, and to improve survival in mouse xenograft tumor models [2, 3].