Earlier this year, the Supreme Court finally resolved an issue that divided the U.S. Court of Appeals for the Federal Circuit (CAFC) for nearly 20 years. In Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831, the Supreme Court unanimously held that a trial court’s underlying factual determinations with respect to extrinsic evidence used in patent claim constructions must be reviewed on appeal under the clearly erroneous standard rather than de novo.1
Before the Supreme Court’s decision in Teva, the CAFC reviewed patent claim constructions de novo, including any allegedly fact-based questions relating to the trial court’s claim construction. As a result, it was quite common for the CAFC to reverse a trial court’s claim construction well after the completion of a lengthy jury trial. The case would be remanded to the trial court (unless the CAFC determined that the error would not have affected the judgment), in some instances leading to an entirely new trial on the merits (and, perhaps, another appeal to the CAFC). After Teva, many hope that CAFC claim construction reversals will be less frequent, particularly when litigants are able to introduce extrinsic evidence such as expert witness testimony into the claim construction process.
The CAFC has now had an opportunity to reconsider on remand not only its decision in Teva, but also Lighting Ballast Control LLC v. Philips Electronics N.A. Corp. which the Supreme Court also remanded to the CAFC for reconsideration in light of Teva.…