Jennifer R. Turchyn*

Congress enacted the Leahy-Smith America Invents Act to encourage innovation, strengthen U.S. patents, and achieve greater uniformity with foreign patent systems. The America Invents Act introduced two new post-grant patent validity proceedings: inter partes review and post-grant review. The new U.S. proceedings are similar to European opposition proceedings, but there are significant differences in the extent of the patent owner’s ability to amend claims, the patent’s claim construction, the patent owner’s evidentiary burden, and the procedural requirements. The U.S. proceedings result in a very limited opportunity for amendment and a high percentage of invalidated patents. In contrast, European opposition proceedings are generally more conducive to upholding patents, whether in original or amended form. The current U.S. practice f