The Federal Circuit held that statements made by a patent owner in an IPR, whether before or after institution, can be considered during claim construction in district court litigation and relied upon to support a finding of prosecution disclaimer in Aylus Networks, Inc. v. Apple Inc., No. 2016-1599 (Fed. Cir. May 11, 2017).

Aylus sued Apple for patent infringement in the Northern District of California. Apple subsequently filed two IPR petitions at the USPTO challenging Aylus’s patent. Aylus filed preliminary responses in both proceedings. In the preliminary responses, Aylus made certain statements about its claims attempting to distinguish the claims from the prior art. The district court determined that Aylus’s statements to the USPTO were clear and unmistakable disclaimers of claim scope and narrowly construed the claims. Based on this narrow construction, the district court granted a motion for summary judgment of non-infringement.

On appeal, the Federal Circuit held that Aylus’s statements from the IPRs could be relied upon to support a finding of prosecution disclaimer. The court reasoned that prosecution disclaimer ensures that claims are not “construed one way in order to obtain their allowance and in a different way against accused infringers.” The court determined that a patent owner’s preliminary response is publicly available, an official paper filed with the USPTO, and a document in which the patent owner can define claim terms and otherwise make representations about claim scope. Thus, the extension of prosecution disclaimer to statements made in an IPR, whether before or after an institution decision, ensures that claims are not argued one way in order to maintain patentability and a different way against accused infringers.

Prosecution disclaimer requires clear and unmistakable disavowing actions or statements. The Federal Circuit agreed with the district court that Aylus’s statements from the IPRs were clear and unmistakable disavowals of claim scope. Therefore, the district court’s claim construction and summary judgment of non-infringement were affirmed.