Patent Docs: Supreme Court revises patent claim construction review standards

Decision comes out of Teva v. Sandoz case and changes standards used for more than a decade

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The U.S. Supreme Court handed down an important patent decision recently in Teva v. Sandoz, changing the standards used by the Court of Appeals for the Federal Circuit that have been applied for over a decade.
By way of background, a patent is comprised of two interrelated parts: the specification, which describes the invention in sufficient detail that the skilled worker will be able to practice it after the patent expires, and the claims, which define the patentee’s legal right to exclude others from making, using, selling, offering to sell or importing the invention during the patent term. The scope and meaning of patent claims in litigation are determined by the trial court as a matter of law, according to an earlier Supreme Court decision (Markman v. Westview Instruments). The Federal Circuit, in deciding the standard of its review of those trial court decisions in Cybor v. FAS Technologies, adopted a completely de-novo standard, wherein neither the legal nor the factual determinations by the trial court were given any deference.
The Teva case involved the meaning of the term “molecular weight” as used in the claims. The trial court had considered expert testimony regarding three meanings for the term used in the art; these are the “peak average molecular weight” (Mp, defined as the weight of the molecule that is most prevalent in a mixture); the “number average molecular weight” (Mn, defined as the average weight of all the different-sized molecules in the mixture); or the “weight average molecular weight” (Mw, determined by calculating the average weight of all the different-sized molecules in the mixture while giving heavier molecules a weight-related bonus when doing so). The trial court decided that the term meant the peak average molecular weight, and thus that the claim was sufficiently definite that it was not invalid. The Federal Circuit construed the claim without regard to the trial court’s determination and found the claim invalid for indefiniteness.
The Supreme Court reversed, holding that the Federal Circuit must give deference to trial court decisions related to “subsidiary” facts upon which the court bases its legal construction of patent claims. No such deference is required when the trial court restricts it consideration to the “intrinsic” evidence (the claim language, the specification and the written record before the Patent Office), but any factual determinations by the trial court based on evidence outside that record (e.g., treatises, dictionaries, expert testimony) must be given deference by the appellate court and reversed only if the reviewing court finds clear error (i.e., actual mistake) in the factual findings.
The Court’s asserted rationale was that standards for review of patent claim construction practice should be consistent with how other appellate courts review mixed questions of law and fact like claim construction (specifically, construing deeds and contracts). This standard of review was based on a trial court’s “greater opportunity to engage its capabilities of assessing the credibility of the witnesses and its capacity to immerse itself in the technical minutiae attendant upon construing claims in the first place.”
The decision settled a question in the law that has bedeviled the Federal Circuit since the Cybor decision, being criticized by the patent bar, academics and even members of that court; much of this dissent related to the practice’s encouragement of every patent decision (because they all involve claim construction by the trial court) and the relatively high frequency of reversal because the Federal Circuit came to a different conclusion on the facts. However, applying the Supreme Court’s mandated standard raises the risk that U.S. patent practice will lose some of the harmonizing effect that was the principal motivation for and the primary benefit of having a specialized appellate court for patents. This is because matters of claim construction are often very dependent on the types of “factual” evidence for which the Federal Circuit must now give deference. Parties in patent litigation can be expected to try to make as much of the claim construction process before the trial court as possible dependent on expert testimony and other “subsidiary” fact-finding, to reduce the likelihood of having the trial court decision overturned on appeal. It is also possible that patentees (at least for patent applications filed after Teva) will try to limit the opportunity for such fact-finding by providing explicit definitions in their specifications.
For highly complex technologies including biotechnology and pharmaceutical patents, it is likely that trial court judges will need expert or other testimony to understand the language of the claims even in the face of such express definitions. Thus, the Teva decision is likely to shift the center of patent claim construction towards the trial courts and away from the Federal Circuit. This can be expected to influence both how patents for pharmaceuticals are drafted, prosecuted and litigated in ways that are in some ways predictable and in others are beyond prediction.

Kevin Noonan is a partner with the law firm McDonnell Boehnen Hulbert & Berghoff LLP and represents biotechnology and pharmaceutical companies on a myriad of issues. A former molecular biologist, he is also the founding author of the Patent Docs weblog,

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