BTI-322 for acute rejection after renal transplantation

BTI-322/LO-CD2a, a rat IgG2b, anti-CD2 monoclonal antibody which binds to all human T and natural killer (NK) cells, was first produced at our Institution1 and was first administered to patients on a compassionate-use basis in 1992. Four patients (three with renal allograft rejection and one with graft-versus-host-disease [GVHD]) resistant to standard therapies received treatment with LO-CD2a 10 mg/d intravenously (IV) for up to 12 days, plus steroids. In all cases, the drug was well tolerated, with no evidence of undesirable side effects; significant clinical benefit was demonstrated in each case. In 1993, LO-CD2a was successfully produced in vitro and became known as BTI-322. A study was initiated to evaluate the safety and determine the minimally effective dose of BTI-322 for treatment of either the first episode of acute renal allograft rejection (group AR) or uncontrolled rejection (rescue therapy; group RT).