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Poring Over Enablement: Pacific Biosciences of California, Inc. v. Oxford Nanopore Technologies, Inc.


In a recent case analyzing enablement and the weight of remarks made at trial about a technology’s relevance to COVID-19, the Federal Circuit affirmed a United States District Court for the District of Delaware jury’s determination that claims asserted by Pacific Biosciences of California, Inc. (PacBio) against Oxford Nanopore Technologies, Ltd. (Oxford) were invalid for lack of enablement. PacBio had sued Oxford in district court, accusing Oxford of infringing several DNA sequencing methodology patents, including U.S. Patent Nos. 9,546,400 (‘400 patent) and 9,772,323 (‘323 patent). The jury found that all claims were infringed, but the claims were invalid for lack of enablement. PacBio moved for judgment as a matter of law and for a new trial, arguing that the jury erred in finding lack of enablement, and that the jury was prejudiced by remarks made regarding COVID-19 treatments during Oxford’s opening statement. The district court denied PacBio’s motion, and the Federal Circuit affirmed.


PacBio’s ‘400 and ‘323 patents (which share a specification) were alleged to encompass methods for sequencing DNA using nanopore technology. Nanopore technology draws nucleic acids “through nanometer-sized holes formed in a [membrane-bound] substrate, and while they transit the holes, their sequences of nucleotides are identified or characterized based on changes in electric current passing through the substrate.” The limitations at issue cover the step of “determining a sequence of the template nucleic acid” by measuring electric current while the nucleic acid is drawn through the hole in the substrate. Both patents claimed priority to April 2009.

On their face, the asserted claims of the ‘400 and ‘323 patents do not distinguish between the particular type, or “character,” of the “template nucleic acid” to be sequenced. Oxford argued that the asserted claims were thus broad enough to encompass both synthetic hairpin DNA molecules and naturally-occurring (or “biological”) DNA molecules. The jury heard testimony that the first successful nanopore sequencing of biological DNA molecules did not occur until 2011; and that at a 2012 conference of scientists in the field in which Oxford presented data showing successful sequencing of biological DNA using its own technology, the audience of 700 reacted with palpable excitement. The jury also heard testimony that PacBio acknowledged that it had not actually reduced the asserted claims to practice, nor performed any type of nanopore sequencing, as of the 2009 priority date.

Background & Procedural History

PacBio brought suit in Federal District Court for the District of Delaware in 2017, alleging in separately filed cases that Oxford had infringed its ‘400 and ‘323 patents (and other patents that were not at issue on appeal). Prior to trial, the district court granted PacBio’s motion in limine (MIL) preventing Oxford from “putting before the jury evidence...about the potential impact of a verdict in favor of PacBio - such as higher prices or slower medical research.” The night before trial, which began on March 9, 2020, Oxford’s counsel notified PacBio’s counsel that Oxford’s opening would mention COVID-19 and the relevance of the DNA sequencing technology at issue to dealing with this virus, and PacBio’s counsel did not object.

PacBio’s opening statement at trial mentioned “in passing” that the technology at issue may advance research related to COVID-19 vaccines. However, Oxford’s opening referred to COVID-19 “more extensively” than PacBio’s and described Oxford’s desire to “send [its accused] products to Wuhan, China at the outset of the coronavirus outbreak” for the purpose of “infectious disease monitoring.” Oxford made those remarks in the context of alluding to PacBio’s seeking to exclude Oxford’s products from the market. PacBio then objected to Oxford’s opening, and the district court agreed to give a curative instruction to the jury, which stated in relevant part: “ are only being asked to award monetary compensation to PacBio. You are not being asked to exclude any Oxford product from the market or stop any research work being performed.”

The district court jury found that all asserted claims of the ‘400 and ‘323 patents were infringed, but that all asserted claims were invalid for lack of enablement. PacBio renewed a motion for judgment as a matter of law, and moved for a new trial, arguing that a) the jury’s enablement verdict was not supported and b) that Oxford’s statements during its opening were prejudicial and inflammatory. The district court disagreed and denied PacBio’s motion, noting that the “record as a whole did contain substantial evidence to support the verdict of non-enablement.” It also explained that there was “no indication...that this jury was inflamed, [or] that it was not careful.” PacBio appealed.

Federal Circuit's Decision


After reviewing the district court’s decision de novo, the Federal Circuit affirmed the district court’s judgment. In explaining the relevant enablement law, the court stated that 35 U.S.C. §112 enforces the “essential quid pro quo of the patent bargain by requiring a patentee to teach the public how ‘to practice the full scope of the claimed invention,’” and noted that a claim is not enabled if an artisan would not be able to practice the claimed invention without undue experimentation. The court quoted Amgen v. Sanofi, 987 F.3d 1080, 1084 (Fed. Cir. 2021) in providing the factual test for whether undue experimentation is required: “(1) the quantity of experimentation necessary, (2) the amount of direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims.” The court relied on this test - known as the Wands factors, in assessing whether the jury had properly found non-enablement.

In applying the Wands factors, the court noted that:

It is not enough for enablement here that relevant artisans knew how to perform some ‘nanopore sequencing’ before the priority date of the ‘400 and ‘323 patents. What matters is the scope of the asserted claims, which (taken as a whole as PacBio does) claim methods of ‘determining the sequence of the template nucleic acid,’ without limiting the character of that ‘template nucleic acid,’ by measuring certain properties (in particular, electric current properties) as the nucleic acid passes through a nanopore, using a determination of the number of nucleotides that affect the current (N), and using enzymes to control the rate of passage through the nanopore. . . . Notably, PacBio acknowledges that the ‘400 and ‘323 patents do not differentiate between ‘particular types of DNA.’

In reviewing the expert testimony provided to the jury, the court stated that it was not the jury’s task to view one portion of that expert testimony in isolation, but rather the jury was to consider all evidence as a whole. In reviewing the testimony and evidence as a whole, the court noted that “there was substantial evidence that supported non-enablement.” In particular:

  • One of Oxford’s experts testified that the “asserted claims of the ‘400 and ‘323 patents lack enablement because of the required element of determining ‘N’ (how many nucleotides affect the current measurement during transit of nucleic acid through the nanopore);

  • There was no indication that the success of scientists in 2011 in performing sequencing of biological DNA was made possible by virtue of the public availability of the disclosures of the ‘400 and ‘323 patents;

  • “When Oxford announced its success in 2012 at a large meeting of scientific professionals in the field, three years after the priority date of the patents at issue, the audience of 700 reacted in a way that suggests that the advance regarding nanopore sequencing with biological DNA was a major one;”

  • PacBio did not show evidence of “actual reduction to practice of its own that would undermine Oxford’s evidence of non-enablement;” and

  • “The jury had evidence...that conveyed an intent by PacBio to ‘tangle up. . . and fool’ competitors with its patents, language that might be understood to point away from PacBio’s having achieved an enabled method.”

In viewing the facts in the light most favorable to the non-moving party (Oxford), the court found that there was ‘ample evidence to support a finding that, before the 2009 priority date of the ‘400 and ‘323 patents, relevant artisans did not know how to perform nanopore sequencing for more than a narrow range of the full scope of nucleic acids covered by the claims.” Therefore the court agreed the disclosures of the ‘400 and ‘323 patents required undue experimentation to enable the full scope of the asserted claims.

Opening Statement Remarks

In reviewing the district court’s refusal to grant a new trial based on alleged improper remarks to the jury, the Federal Circuit noted that a new trial may be granted when “it is ‘reasonably probable’ [that Oxford’s] prejudicial remarks influenced the jury’s verdict.” The court noted that the standard of review is abuse of discretion, and the law gives “considerable weight” to the views of the judge who supervised the trial.

In finding that the district court did not abuse its discretion, and that its denial of a new trial was proper, the Federal Circuit underscored that PacBio also mentioned COVID-19 in its opening, and that while Oxford’s references to the virus were more extensive, the court “gave exactly the curative instruction that PacBio requested” to the jury. Further, the court noted that Oxford did not mention COVID-19 again or otherwise violate the MIL order, and that the jury’s questions to the court before reaching its verdict showed careful deliberations and that the jury was not prejudiced by Oxford’s opening statement. “In sum, we see an inadequate basis here to substitute our judgment about prejudice for the judgment of the district court.”

Key Takeaways

  • The court emphasized the “peril” of drafting claims with broad language, as this can place at risk for invalidation “any claim that cannot be enabled across its full scope of coverage.” At the same time, any determination of the “full scope of coverage” of a claim by a tribunal often involves line-drawing. Thus, where possible, consider fall-back positions in drafting, i.e., adding dependent claims that cover specific embodiments that are actually reduced to practice.
  • Litigants who file a motion in limine to exclude certain remarks from being presented to a jury on prejudicial grounds should take care not to present similar remarks themselves. Draw a “fence around the fence” to steer clear of excluded topics during opening statement preparation.