In yet another appellate case with spirited dissents, the Court of Appeals for the Federal Circuit (CAFC) continues to reveal differences of opinion among members of the court in how precedent and the use of extrinsic evidence should guide current decisions. In the recent case of Biogen International GmbH v. Mylan Pharmaceuticals, which dealt with the adequacy of a patent’s written description under 35 USC §112, there were strong dissents in the panel decision and in the court’s denial of requests for a panel rehearing and rehearing en banc.
