By Ilan Zipkin
Science Editor

The final Markman hearing in Amgen Inc.'s erythropoietin patent infringement suit against Transkaryotic Therapies Inc. and Aventis Pharmaceuticals shed perhaps even less light on the issues that will decide the case than did the previous two hearings into AMGN's patent claims. In any case, the judge in the case last week made clear that the outcome ultimately will turn on upcoming arguments about whether AMGN in fact enabled the claims in its patents for EPO.