pexelizumab pexelizumab pexelizumab is a drug designed to reduce side effects of coronary artery bypass grafting and angioplasty, among other types of cardiac surgery. it is a single chain variable fragment of a monoclonal antibody targeted against component 5 of the complement system. pexelizumabmonoclonal antibodytypesingle-chain variable fragmentsourcehumanized (from mouse)targetcomplement component 5clinical dataatc codenonelegal statuslegal status investigational identifierscas number219685-93-5 ychemspidernoneuniichz6olq3uukeggd10023 n ny (what is this?) (verify) current status alexion, the developer of pexelizumab, stopped development when the phase 3 trial indicated the heart-attack drug is no better than placebo.