Academic journal article Boston University Law Review

Prejudicial or Probative: Determining the Admissibility of Decisions in Inter Partes Review Proceedings

Academic journal article Boston University Law Review

Prejudicial or Probative: Determining the Admissibility of Decisions in Inter Partes Review Proceedings

Article excerpt


The Leahy-Smith America Invents Act ("ALA"), passed by Congress in 2011,1 is the most significant piece of patent reform legislation since 1952.2 Two important changes implemented by the AIA were the creation of post-grant opposition procedures that allow third parties to challenge the validity of issued patents before the U.S. Patent and Trademark Office ("PTO"),3 and the creation of the Patent Trial and Appeal Board ("PTAB"), an adjudicatory board within the PTO.4 Inter partes review ("IPR"), one of the post-grant opposition procedures created by the AIA, allows a third party to challenge the validity of one or more patent claims before the PTAB.5 IPR proceedings were intended to provide a more efficient, cost-effective alternative to challenging the validity of issued patent claims in federal court.6 IPR, which is by far the most popular of the new post-grant proceedings, has become a significant player in patent validity challenges and patent infringement litigation.7 In contrast to federal court suits, a challenger does not have to show standing to bring an IPR. Challengers do, however, need to show a reasonable likelihood of prevailing on one of the challenged claims for the PTAB to institute an IPR.8 Patent claims can also be challenged in federal court as an affirmative defense to patent infringement.9 Prior to the AIA, infringement suits in federal court were by far the most common context in which validity challenges arose.10

Because both federal courts and the PTAB are able to decide issues of patent claim validity, situations may arise where the PTAB has already made a decision on the validity of a patent being litigated in federal court, or vice versa.11 One common scenario is that party A will bring an infringement action against party B in federal court, claiming that B infringed A 's patent. In response, B will bring an IPR claiming that A's patent is invalid and, therefore, cannot be infringed.12 In this situation, the court will usually allow the parties to stay the federal court litigation until the IPR is adjudicated.13

It is often favorable for defendants in infringement suits to bring IPRs rather than challenge the validity of patents in court, in part because it cuts down on cost14 and partly because patents are easier to invalidate in IPRs due to different legal standards and a lower burden of proof at the PTO.15 If the patent is found invalid in the IPR, then the federal court action is dismissed. If the patent's validity is upheld in the IPR, then the litigation moves forward and the defendant is prohibited from raising any issue in court that she raised or reasonably could have raised in the IPR.16

One important rule of patent validity challenges is that once a patent is found invalid, either in court or before the PTAB, it is invalid against the world.17 However, a finding of validity by the PTAB does not generally prevent subsequent challenges to that patent's validity by other parties,18 and the PTAB is not bound by a court's refusal to find a patent invalid.19 For example, if the PTAB upheld the validity of A 's patent, there is no rule prohibiting a different party, C, from challenging the same patent's validity in a later infringement suit.20

The fact that a patent that has been challenged before the PTAB can later be involved in litigation creates a unique evidentiary issue. As illustrated above, a patent that has been found valid in an IPR could be subject to a later infringement suit with a defendant who was not a party to the IPR. The defendant in the subsequent infringement suit, party C, would be able to challenge the validity of A's patent, even though the patent's validity had been previously upheld in an IPR with party B.21 So far, there is no rule concerning whether a finding of validity in an IPR can be presented as evidence to a jury during a subsequent infringement suit. Further, there is no consistent rule as to whether a PTAB decision refusing to institute an IPR can be admitted as evidence to a jury in an infringement suit. …

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