Judge Richard G. Andrews recently granted a motion to dismiss upon consideration of an an affirmative defense under 35 U.S.C. § 252 relating to claims re-issued following inter partes reexamination. Waters Techs. Corp. v. Aurora SFC Sys. Inc., Civ. No. 11-708-RGA (D. Del. Aug. 21, 2017). Judge Andrews explained that, as currently plead, “it is not plausible that a substantive limitation was not added to the Amended Claims,” because “[n]one of the Asserted Claims that came out of reexamination had a differential pressure transducer limitation[,]” meaning that the claims had substantively changed for purposes of section 252. Id. at 6. In fact, the plaintiff did not disagree, but instead “only argues that this decision is premature absent claim construction and discovery.” Id. Judge Andrews disagreed, and explained that it was implausible to infer that no substantial changes resulted from the IPR. Therefore, the Court dismissed the plaintiff’s claims based on section 252 with respect to infringement prior to the re-issuance.