Amendment Based Estoppel at PTAB?

Remember the Doctrine of Equivalents (DOE)?

DOE was that folksy doctrine that allowed some wiggle room in proving patent infringement where a claim term was not literally met. That is, DOE allows a patent owner to reach an equivalent claim element functioning in the same way, to achieve the same result that is utilized to side-step the literal claim language. DOE is the type of legal argument that litigators live for. Unfortunately, the doctrine was all but laid to rest decades ago in the Supreme Court’s Festo decision as most prosecution changes will foreclose DOE. Still, there is an occasional throwback case that attempts to litigate DOE.

Most recently, Columbia University faced a summary judgment motion arguing that its DOE-based assertion was precluded by amendment based estoppel — as a result of PTAB claim cancellation alone.

The case, Trustees of Columbia University in the City of New York v. NortonLifeLock Inc., considered the impact of earlier concluded IPRs of two of the asserted patents: U.S. Patent Nos. 8,074,115 (“the ’115 Patent”) and 8,601,322 (“the ’322 Patent”). The PTAB ultimately determined that thirty claims of the ’115 Patent and twenty-one claims of the ’322 Patent were unpatentable under 35 U.S.C. §§ 102 and 103. These decisions (after some claim cancellations of independent claims) left twelve dependent claims remaining in the ’115 Patent.

When back before the district court, the defendant argued that the remaining dependent claims were subject to amendment-based prosecution history estoppel, which would preclude infringement claims premised on DOE. the defendant argued that Columbia should be estopped from asserting infringement under DOE because the corresponding independent claims of the ’115 Patent were cancelled during IPR. Columbia countered that no court had applied amendment-based prosecution history estoppel under these circumstances.

The court while acknowledging that IPRs constitute prosecution history, sided with Columbia, explaining (here):

[T]here is no law to support that the mere ‘fact of claim cancellation during IPR’ without any accompanying arguments made by Columbia gives rise to the Festo presumption . . . In essence, Norton asks this Court to make new law that amendment-based estoppel applies in inter partes review because “there is no reason to draw a distinction between argument and amendment based estoppel in inter partes review.”

(emphasis added)

While the Court held that even if the amendment-based estoppel applied, that presumption was overcome anyway, it is especially odd that the Court would acknowledge that IPR briefing constitutes prosecution history, but then identify a distinction that doesn’t exist in assessing a prosecution history. The court distinguished Not Dead Yet Mfg., Inc. v. Pride Sols., LLC, a 2017 case from the Northern District of Illinois applying prosecution history estoppel based on an IPR proceeding. The court noted that Not Dead Yet involved argument-based estoppel, not amendment-based estoppel. But, there is nothing special about IPR prosecution history as compared to application prosecution history.

To the extent you are at all concerned with DOE issues at the PTAB as a result of claim cancellation, I would not expect this distinction (dicta aside) to be endorsed by the Federal Circuit.