Federal Circuit OK's Use Of Post-Priority-Date Evidence

The ruling found that the use of such evidence was proper for written description and enablement.

The US Court of Appeals for the Federal Circuit issued its opinion on October 5 in Amgen Inc. v. Sanofi, Case No. 2017-1480, in which it was asked to address several evidentiary issues on appeal, including whether the district court improperly excluded post-priority-date evidence Sanofi had offered to show that the asserted patents lacked written description and enablement. The Federal Circuit concluded that such evidence was proper, provided that it was not used to shed light on the state of the art on the priority date, but rather to show proof of lack of written description or enablement. As a result, the court reversed the district court's rulings on written description and enablement and remanded the case for a new trial.