Cancellation of Independent Claims in IPR Does Not Estop Doctrine of Equivalents Arguments for Surviving Dependent Claims
by Jason Weil, Rubén H. Muñoz, Megan Mahoney (Law Clerk)
Patent Trial and Appeal Board, Inter Partes Review, Doctrine of Equivalents, Eastern District of Virginia
Jan. 31, 2022
A judge in the Eastern District of Virginia recently held that cancellation of independent claims in an inter partes review (IPR) did not preclude the plaintiff from asserting infringement based on the doctrine of equivalents for surviving dependent claims. The district court found that, as a matter of law, amendment-based prosecution history estoppel does not apply based on the Patent Trial and Appeal Board’s cancellation of all independent claims of the patent.
Plaintiff Columbia University asserted patent infringement against Defendant Norton’s antivirus software, including under the doctrine of equivalents. Defendant challenged the patents in an IPR, and the PTAB found unpatentable all independent claims of one of those patents. There was no motion to amend filed in the IPR. Later, in the district court, Defendant moved for partial summary judgment, arguing that amendment-based prosecution history estoppel forecloses a doctrine of equivalents argument related to the surviving dependent claims of that patent. Specifically, Defendant argued that cancellation of an independent claim to pursue dependent claims gives rise to a presumption of prosecution history estoppel. In response, Plaintiff noted that no court has ever applied amendment-based estoppel to the cancellation of independent claims in IPR proceedings.
The court explained that, under amendment-based estoppel, there is a presumption that a narrowing amendment made to achieve patentability during prosecution surrenders the entire subject matter—including any equivalents—between the original claim limitation and the amended claim limitation. Here, the court found that the mere fact of claim cancellation during IPR, without accompanying argument, could not give rise to amendment-based prosecution history estoppel. Accordingly, Plaintiff was not estopped by amendment-based estoppel from pursuing its infringement claim under a doctrine of equivalents theory.
Practice Tip: Patent owners seeking to assert infringement under the doctrine of equivalents should be mindful of possible estoppel resulting from patentability arguments and claim amendments. At least one court has found however, that mere cancellation of independent claims in an IPR will not preclude a doctrine of equivalents theory for remaining dependent claims.
Trustees of Columbia University in the City of New York v. NortonLifeLock Inc., 3-13-cv-00808 (E.D.V.A. Dec. 23, 2021)
PGR Challenge to Genus Claims Fails Because of Enabling Disclosure of Species in Pre-AIA Priority Applications
by Jonathan James Underwood & Rubén H. Muñoz
Patent Trial and Appeal Board, Post-Grant Review , Patent Litigation
Mar. 15, 2022
The Patent Trial and Appeal Board has denied institution of a post-grant review proceeding because the petitioner failed to show the challenged patent was eligible for PGR. The PTAB ruled that the petitioner’s evidence, including expert testimony, did not show that the claims in the challenged patent lacked enablement by the disclosures of two PCT applications from which the challenged patent claimed priority. Because the challenged patent claimed the benefit of the two PCT applications, and those applications were filed before March 16, 2013, it was not eligible for PGR.
The challenged claims were methods of improving human endurance during exercise. The claims included the step of administering an amount of an inorganic nitrate from a specified range that was based on body weight. The petitioner did not dispute that the PCT applications disclosed the claimed range, rather, even with the disclosures, a skilled artisan would have to perform undue experimentation to practice the full scope of the claims. The petitioner argued that the upper end of the range encompassed lethal doses of the inorganic nitrate, as shown on a webpage archived by the Wayback Machine. The petitioner also argued that the only working example in the PCT applications was a much lower dose of nitrate, which could only show hope, but not support, for the higher range. The petitioner supported its arguments with expert testimony. The petitioner also challenged the dependent claims for lack of written description of various elements.
The PTAB first found that the archived webpage was inadmissible because it had not been authenticated. The PTAB explained that the petitioner could have verified the webpage as a business record under FRE 901(b)(1), further noting that other evidence had been authenticated by a declarant. But even though the webpage itself was inadmissible, the PTAB explained that the petitioner’s expert could rely on the webpage to form an opinion.
Turning to whether the priority applications were enabling under the Wands factors, the PTAB found the petitioner’s expert’s evidence unpersuasive. First, the working example of the challenged patent disclosed a dose that was tested and that, contrary to petitioner expert’s opinion, was not lethal. Second, the PTAB distinguished the challenged patent from the patent at issue in Amgen, Inc. v. Sanofi, 987 F.3d 1080 (Fed. Cir. 2021). In Amgen, the court found that undue experimentation was required because there were too few examples of antibodies compared with the scope of the large genus claims and amount of effort required to find all of the antibodies. By contrast, the challenged patent’s disclosure allowed the skilled artisan to practice the claims by “simply administer[ing] a different dosage to the human.” Moreover, the challenged patent explained that the particular condition that is the source of the lethality associated with nitrates does not result from the claimed method. Because the petitioner’s expert failed to address this discrepancy, the expert’s testimony was of little probative value.
Finally, the PTAB considered the petitioner’s written description arguments. The PTAB found that a skilled artisan would not have understood the inventors to lack possession of the inventions of the dependent claims. The limitation requiring that the dose be given “at least three days prior to exercise” was supported by the example in which a dose was given more than three days prior to exercise. Similarly, a limitation requiring administration “once a day” was supported by the disclosures of dosing ranges using units in the form “mmol/kg/24h” and administering “single bolus doses.” And the limitation requiring
a combination of the nitrate and “at least one additive” had support from disclosures in the priority applications of using the nitrates with antimicrobials, pH stabilizers, flavors, sweeteners, colors, and emulsifiers.
The PTAB concluded that, on the record before it, the petitioner had not met its burden of showing that any of the claims failed to trace priority to an application filed before March 16, 2013. Thus, the challenged patent was ineligible for PGR, and the petition was denied.
Practice tip: PGR is not available if the challenged claims trace priority to an application filed before March 16, 2013. It is petitioner’s burden to provide sufficient evidence to meet this threshold issue. Because this critical requirement for PGR eligibility often relies on expert testimony, a petitioner should scrutinize its written description and enablement arguments, as well as the supporting expert testimony. Conversely, a patent owner seeking denial of institution should review carefully petitioner’s arguments and supporting evidence, and challenge any identified weaknesses pre-institution.
Human Power of N Company v. Heartbeet Ltd., PGR2021-00110, Paper 7 (PTAB Feb. 25, 2022)