by Alex V. Chachkes and Johannes Hsu | September.21.2018
Ericsson Inc. v. Intellectual Ventures I LLC, Fed. Cir. (Aug. 27, 2018)37 C.F.R. § 42.23(b) limits a petitioner’s inter partes review (“IPR”) reply papers to arguments raised by the patent owner in its opposition. Under this rule, a petitioner cannot assert new invalidity arguments, cite previously unidentified parts of a prior art reference, or introduce new evidence such as a new prior art reference. The line between this and what is merely responsive, however, can be blurry. The Federal Circuit’s recent decision in Ericsson sheds some light on this line.