Officials worried about 'untraceable' drug that could aid endurance

ATLANTA - Officials with the U.S. Anti-Doping Agency said Monday they are keeping a close eye on Repoxygen, an anti-anemia drug that, if used by athletes for performance enhancement, would be virtually undetectable by blood or urine tests. <br> <br> Repoxygen increases levels of erythropoietin (EPO), a hormone that supplies high amounts of oxygen to the muscles and increases endurance. <br> <br> Anti-doping officials, meeting in Atlanta, say they are worried about all forms of blood manipulation to enhance oxygen delivery transfusion of red blood cells, blood substitutes and any way of delivering EPO. <br> <br> But unlike other EPOs, which USADA officials say can be detected by urine tests, Repoxygen is hard to trace through the random blood or urine tests given to athletes at sporting events. <br> <br> Repoxygen encourages the body to produce its own EPO as athletes need it. <br> <br> Bowers says the USADA is already preparing for Repoxygen, even though it is still in the early stages of development. <br> <br> Because the drug -- being developed by British company Oxford BioMedica Plc -- is still in clinical trials, Bowers says the USADA has not yet talked to the company about possible abuse.