In 2003, the Federal Circuit in Amgen Inc. v. Hoechst Marion Roussel, Inc. placed the burden of proving a prior art patent’s § 112 nonenablement on the patentee instead of the accused infringer. The patentee even bears this burden when the unclaimed subject matter is asserted to anticipate the patent at issue. This comment focuses on three questions that were created by the decision in Amgen. First, is material in a printed publication equivalent to unclaimed material in a patent? Second, is the holding in Amgn based on a false premise because it may accord a presumption of § 112 enablement to material that has never been examined by the USPTO for enablement? Third, did the court violate 35 U.S.C. § 282 by moving the burden of proving § 112 enablement from the challenger to the patentee?
Kristina A. Walker, To Be Presumed Or Not To Be Presumed . . . That Is The Enablement Question, 5 J. Marshall Rev. Intell. Prop. L. 140 (2005)