Timing of Estoppel Unimportant

Last week in Novartis Pharmaceutical Corp. v. Par Pharmaceutical Inc., Nos. 14-1289-RGA, 14-1494-RGA, 15-0078-RGA (D. Del. Apr. 11, 2019), (here) the court addressed a motion to estop defendants from asserting invalidity arguments based on prior art references already presented at trial. The motion argued that, in related IPR proceedings brought while litigation was pending, the same defendants challenged and failed to prove the unpatentability of overlapping claims. The Board’s Final Written Decision (FWD) issued during the appeal. (later remanded back to D.Del)

Novartis argued that, irrespective of the timing of the FWD, that the invalidity defenses and counterclaims presented at trial by defendants should be estopped.The court found no issue with the application of IPR estoppel after the district court had already held trial, noting that it did “not think the application of lPR estoppel is dependent on the order in which certain events occur.” By the plain language of the statute, the court did not see any indication that “Congress intended for there to be a time limitation upon the estoppel effect of a final written decision of an IPR.” A previous challenge on the same grounds focused on the use of the terms “request” and “maintain” in § 315(e)(1) and “assert” in § 315(e)(2), but the court found those differences in language to be “a result of the forum in which the estoppel occurs, rather than evidence that Congress intended IPR estoppel to be limited to time before trial is completed.” By the plain language of the statute, IPR estoppel should “still apply post-trial where the Court has not entered a final judgment on the relevant ground.”

Dealing with the specific references already raised in trial, the court found that the defendants were precluded from pursuing the related invalidity arguments on the claims asserted during the IPR proceedings. According to the court, those references would have been found by a diligent search (as they were already found for the purposed of trial), and therefore “could have been raised” at the IPR proceeding.

Of course, losing under a preponderance of the evidence standard at the PTAB would seem to doom the same art under the higher clear and convincing standard. But, more importantly, the “reasonably could have raised” aspect of PTAB estoppel prevents a refinement of the issues based upon PTAB feedback.