PTAB Claim Constructions Often Limited to Intrinsic Record
Yesterday, in Teva Pharmaceuticals USA, Inc., et al v. Sandoz, Inc. et al., (here) the U.S. Supreme Court reversed decades of CAFC precedent permitting de novo review of district court patent claim constructions. More specifically, the high court explained that when reviewing a district court’s resolution of subsidiary factual matters made in the course of its construction of a patent claim, the CAFC must apply a “clear error,” not a de novo, standard of review. This decision will also impact the CAFC’s previous practice of applying de novo review of Patent Trial & Appeal Board (PTAB) claim construction decisions….or will it?
Key to yesterday’s holding is the distinction between intrinsic versus extrinsic evidence. That is, when the district court/PTAB reviews only evidence intrinsic to the patent, the judge’s determination is solely a determination of law, and the CAFC will review that construction de novo. However, where the district court/PTAB needs to consult extrinsic evidence in order to understand, for example, the background science or the meaning of a term in the relevant art during the relevant time period, and where those subsidiary facts are in dispute, courts/PTAB will need to make subsidiary factual findings about the extrinsic evidence, such as expert reports/declarations.
Finally, note that means-plus-function claims will necessarily invoke questions of fact (e.g., structural equivalence). Where competently drafted, such claims provide a mechanism for avoiding the full breadth of a broadest reasonable interpreation, and now, second guessing of structural equivalents on appeal. A strategic smattering of such claims across a portfolio serves as a helpful hedge for patentees in a post-grant challenge setting.