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 indicated for the treatment of patients with anaemia associated with chronic kidney disease. It is the first approved, chemically modified erythropoiesis-stimulating agent. 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 ε-amino group of any lysine present in the protein with methoxy polyethylene glycol butanoic acid. The average molecular weight is approximately 60 kDa. The drug stimulates erythropoiesis by interacting with the erythropoietin receptor on progenitor cells in the bone marrow. It has a reduced receptor binding activity compared to other ESAs and but retains in vivo activity due to an extended serum half-life. It has an in vivo half-life of around 135 hours as compared to darbepoetin alfa which has a half life of around 21 to 70 hours, the half life of which is three times that of the naturally occurring erthropoietin in the body.

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. However, the injunction has since expired and Mircera is available on the US market since 2015.

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 disqualified from 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.