WASHINGTON - The drama surrounding the future of erythropoietin (EPO) has intensified with developments on several fronts, including a decision by the Pharmaceutical Research and Manufacturers of America (PhRMA) to lobby against generics legislation proposed by Amgen Inc. and the start of a Phase III trial of rival Transkaryotic Therapies Inc.'s GA-EPO.

Ironically, while AMGN continues to argue strenuously that the differences between EPO and GA-EPO are trivial, the company is taking the opposite position in a dispute with partner Johnson & Johnson over the significance of differences between EPO and Novel Erythropoiesis Stimulating Protein. NESP is a second generation version of EPO that AMGN hopes will free it of its obligations to split the EPO market with J&J.