pegsunercept pegsunercept pegsunercept is a drug for the treatment of rheumatoid arthritis. as of january 2010, phase ii clinical trials have been completed. it is being developed by amgen. pegsunerceptclinical dataroutes ofadministrationsubcutaneous injectionatc codenonelegal statuslegal status investigational pharmacokinetic databioavailabilityn/aidentifierscas number330988-75-5 nchemspidernoneuniiq5i7sfz853keggd05393 ychemical and physical dataformulac502h758n154o165s16molar mass12,103 g/mol (protein part) g·mol−1 ny (what is this?) (verify) similarly to etanercept, pegsunercept is a soluble tumor necrosis factor receptor. pegsunercept is a pegylated protein.