A murine IgM monoclonal antibody (MoAb) developed for the potential treatment of graft versus host disease (GvHD). Gavilimomab recognizes human CD147 antigen, weakly expressed on human leukocytes and up-regulated on activated lymphocytes. This MoAb is capable of neutralizing inflammatory reactions via a complement-dependent cytotoxic mechanism. However, gavilimomab does not offer an improvement over antithymocyte globulin in the treatment of acute steroid resistant GVHD. Check for active clinical trialsusing this agent.