Should an IPR petitioner be able to submit its first expert declaration during reply briefing? In Belden Inc. v. Berk-Tek LLC, the Federal Circuit affirmed the PTAB’s decision to allow a petitioner to do just that. According to the court, the PTAB did not abuse its discretion by allowing the declaration because the testimony fairly responded to points made by the patent owner’s expert and was not necessary for the petitioner’s prima facie case of obviousness (consistent with the requirements of 37 C.F.R. § 42.23(b) and guidance of the Patent Office Trial Practice Guide).

While the holding in Belden is narrow, the Federal Circuit suggested that the PTAB has considerable discretion to allow petitioners to provide expert declarations for the first time in reply briefing. Even where such a declaration contains material that should have been included in the petition, the PTAB is not required to exclude the entire declaration, though it retains the discretion to do so. The Federal Circuit further observed that the PTAB can consider new matter in a reply declaration so long as the patent owner is provided notice and a fair opportunity to respond. Such an opportunity to respond may include the patent owner’s ability to (1) cross-examine the expert and move to file observations, (2) move to exclude the declaration, (3) dispute the substance of the declaration at the hearing, and/or (4) move for permission to file an additional reply.

As a result of this decision, a petitioner should not be afraid to submit an expert declaration for the first time during reply briefing, as long as the declaration is tailored to refuting the patent owner’s responsive briefing and is not necessary to proving unpatentability. However, a petitioner should always file a complete case with its petition and should not plan on using a reply declaration to establish anything necessary to winning its case.  

A patent owner can still object to any new matter presented in a reply declaration, but should consider whether to substantively address the contested statements.