The latest casualty in the ongoing patent and marketing dispute between Biogen Inc. and Schering AG came last week in the revocation by the European Patent Office (EPO) of BGEN's so-called "Fiers patent" covering production of recombinant beta-interferon.

The patent issued in 1990, and soon thereafter was contested by Schering. In 1994 Schering's opposition was denied, but that decision has now been overturned upon appeal, which cannot be challenged.