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.