En langsommere binding til og hurtigere adskillelse fra receptoren, en reduceret, specifik in vitro aktivitet med en forøget aktivitet in vivo, og desuden en forlænget halveringstid i modsætning til erythropoetin.
Methoxy polyethylene glycol-epoetin beta, the active substance of MIRCERA, is a continuous erythropoietin receptor activator that shows a different activity at the receptor level characterized by a slower association to and faster dissociation from the receptor, a reduced specific activity in vitro with an increased activity in vivo, as well as an increased half-life, in contrast to erythropoietin.