Methoxy polyethylene glycol-epoetin beta

Methoxy polyethylene glycol-epoetin beta is the active ingredient of a drug marketed by Hoffmann-La Roche under the brand name Mircera. Mircera is a long-acting erythropoietin receptor activator (CERA) indicated for the treatment of patients with anaemia associated with chronic kidney disease. It is the first approved, chemically-modified erythropoiesis-stimulating agent (ESA). Mircera is supplied as a solution in pre-filled syringes for intravenous or subcutaneous administration. Mircera was approved for use in Europe in July 2007 by the European Commission, in September 2007 by the Swissmedic, and in November 2007 by the U.S. Food and Drug Administration for use in the United States.

Methoxy polyethylene glycol-epoetin beta is made from erythropoietin by chemically linking the N-terminal amino group or the Є-amino group of any lysine present in the protein with methoxy polyethylene glycol butanoic acid. The average molecular weight is approximately 60kDa. The drug stimulates erythropoiesis by interacting with the erythropoietin receptor on progenitor cells in the bone marrow.

Patent infringement claims
A U.S. Federal Appeals Court ruled 15 September 2009 that Mircera infringes a patent held by Amgen Inc.. The court refused to lift an injunction entered in the fall of 2008 which barred Roche from selling Mircera in the United States.

Use in sports
Mircera can reportedly replace traditional EPO drugs as blood doping agent in endurance sports. The drug appears to fall under section S2 of the list of substances officially prohibited - in competition and out of competition - in France and by the World Anti-Doping Agency.

On July 17, 2008, Italian bicycle racer Riccardo Riccò was kicked out of the Tour de France after reports that a urine sample tested positive for Mircera. There had not previously been any public acknowledgment that a test for the new drug was being administered, or had even been developed yet. The Tour de France testing was done under the auspices of the French Cycling Federation and the French Anti-Doping Agency, not the Union Cycliste Internationale.