In Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc., (574 U.S. ___(2105) (Slip Opinion Jan. 20, 2015), the Supreme Court of the United States held that the review of Markman claim construction decisions is now considered a mixed question of fact and law. Any factual determinations based on extrinsic evidence will be reviewed for clear error. The application of those findings to an ultimate construction will still be reviewed de novo as questions of law. Patent litigators will need to support their factual assertions re claim terms at the district court level. There will also likely be disputes over the line between what are fact questions and what are legal constructions. The district courts will also need to make detailed factual findings when they consider and rely on extrinsic evidence in making claim constructions. It is unclear if this will complicate or simplify issues on review or whether it will lead to more certainty in claim construction review on appeal. It does seem likely to lead to more litigation issues at the claim construction stage.
Traditionally, a court first looks to the words of the claim themselves. If they are clear on their face and not ambiguous then there is no need to resort to extrinsic evidence (an approach used in construing contract terms that SCOTUS relied on by analogy in Teva) and hence the resulting claim construction would be reviewed de novo. Parties may try to submit extrinsic evidence on whether a term is ambiguous. They may try to argue that the construction within the entire claim and in view of the entire specification of a factual determination of a claim term meaning is a legal determination and thus review of that legal determination is de novo. The Teva ruling encourages litigation over whether and when a claim construction is a factual or legal issue because that drives the standard of review.
美最高法院1月20日在Teva案子的决定中，对专利诉求范围的确定复审将分为对“事实发现”，和“法律解释”两部分。“事实发现”部分的复审标准将是查看”有无明显错误”，而“法律解释”部分复审标准将是“从头”复审。之前对专利诉求范围的确定都属于“法律解释”范围，从而复审时是依从“从头”复审的原则。
