In Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014), the Supreme Court rejected the Federal Circuit’s “insolubly ambiguous” standard for determining whether a patent claim meets the definiteness requirement under 35 U.S.C. §112, ¶ 2, and held that “a patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.” In the ensuing one and a half years, the Federal Circuit and several trial courts have applied the Nautilus standard in the biotechnology and pharmaceutical contexts. We discuss three notable decisions.

In Teva Pharms. USA, Inc. v. Sandoz, Inc., 789 F.3d 1335 (Fed. Cir. 2015), the Federal Circuit, on remand from the Supreme Court decision in Teva Pharms. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831 (2015), found a disputed patent claim indefinite in part based on conflicting representations made by the patentee during the prosecution of two related applications. The term was “molecular weight,” or average molecular weight in the context of a synthetic copolymer. The concept of average molecular weight is also relevant to technologies concerning other macromolecules, such as proteins and DNA. Specifically, the Federal Circuit found that while average molecular weight can be ascertained by any of three possible measures, the claims do not indicate which measure to use, and the specification does not define molecular weight or mention any of the three measures. Additionally, the patentee argued conflicting positions during prosecution of two related patents containing identical disclosure, stating that one measure applies in one application and another applies in the other application. In light of the specification and the prosecution history of the related applications, the Federal Circuit held that the patentee failed to meet the reasonable certainty standard under Nautilus.

In Regeneron Pharms., Inc v. Merus B.V., 2014 U.S. Dist. LEXIS 163350 (S.D.N.Y. Nov. 21, 2014), the district court held a term in a patent related to genetic technologies indefinite because its metes and bounds cannot be determined with reasonable certainty. The patent relates to a mouse genetically modified to include human DNA at specific locations of a mouse chromosome. The disputed term was “endogenous mouse immunoglobulin locus.” The court found it significant that the specification never used the disputed term, and never informed the reader how to find the immunoglobulin locus. While mentioning the use of structural or functional data to select a locus, the specification provided no specific data for locating the “endogenous mouse immunoglobulin locus.” The court also found it relevant that the boundaries of the locus were unknown in the research community at the time of the patent filing. Finally, the court noted that one skilled in the art could not ascertain the scope of the invention because there is significant variation in the location of the locus among mice of different strains, and yet the specification lacks information as to the specific strains.

In Purdue Pharma L.P. v. Amneal Pharms., LLC (In re OxyContin Antitrust Litig.), 2015 U.S. Dist. LEXIS 45967 (S.D.N.Y. Apr. 8, 2015), the district court evaluated the question of definiteness based on whether the disputed term impacts the determination of infringement.  The court held a term indefinite because the patent did not tell one skilled in the art how to select a related parameter that impacts the results of the infringement analysis. The disputed term was “viscosity of at least about 60 cP.” The court found that the patent permitted the use of a wide range of shear rates, and the choice of shear rate directly impacts the results of viscosity test and determines whether the accused product satisfies the viscosity limitation. Since the patent did not tell one skilled in the art how to select the shear rate, the court found the term indefinite for failing to meet the reasonable certainty standard.

However, the court declined to find the claims indefinite with respect to tampering temperature, testing temperature, or extent of dissolution. While acknowledging that the patent did not set forth precise guidance on these testing variables, the court held that the accused infringer had not shown that these variables impact whether an accused product infringes the patent; rather, the evidence shows that even when one skilled in the art fill the gaps in different ways, their choices do not produce conflicting results on infringement. The court noted Nautilus’s suggestion that a claim is not ambiguous merely because readers “could reasonably interpret the claim’s scope differently.” The court concluded that despite the patent’s lack of specific direction on these variables, one skilled in the art could still discern, with reasonable certainty, the scope of the invention.

The decisions discussed above demonstrate the flexibility in the approaches courts have taken in making a definiteness determination. The Teva decision heavily relied on the prosecution history of related applications. The Purduedecision took a very practical approach and focused on whether the perceived uncertainty in the meaning of the disputed term ultimately created impermissible fuzziness concerning the scope of the invention.

These decisions also highlight the need for providing one-on-one support in the patent specification for the meaning of each term in the claim that does not have a clear ordinary meaning.  Particularly, both the Teva and Regenerondecisions found it significant that the specification did not address the disputed terms. It is important to define the relevant terms in the specification and ensure that the same terminology is used consistently in the specification and during prosecution.