Post-IPR Estoppel Does Not Apply to New Invalidity Theories​

The court granted plaintiff's motion to clarify an earlier order concerning the meaning of "ground for invalidity" for purposes of post-IPR estoppel under 35 U.S.C. § 315(e), but deferred ruling on whether defendant was estopped from asserting a specific theory on invalidity. "[Plaintiff] essentially asks the court to explain what a 'ground for invalidity' is. . . . [T]he defendant is not locked into the precise argument made in its IPR petition. But if the new theory relies on different, uncited portions of the prior art, attacks different claim limitations, or relies on substantially different claim constructions, then the new theory is tantamount to a new invalidity ground, and the court will treat it like a non-petitioned ground subject to estoppel. . . . At this point in the case, I cannot tell who, if anyone, is playing fast and loose with the meaning of [a claim term]. But it hardly seems fair to restrict [defendant] to the claim construction used in the IPR, if [plaintiff] is free to re-tool its infringement case with new claim constructions, as [plaintiff] suggests that it is free to do. I will defer a decision on whether these principles would estop [defendant] from contending that claim 6 is anticipated by Keeler under the alternative interpretation of [the claim term]. The parties are free to argue the § 315(e) estoppel issue at summary judgment."

Douglas Dynamics, LLC v. Meyer Products LLC, 3-14-cv-00886 (WIWD May 15, 2017, Order) (Peterson, USDJ)