Federal Circuit says Assignor Estoppel Has “No Place” in IPR Proceedings
The Federal Circuit recently found that assignor estoppel has “no place in IPR proceedings,” affirming a holding of the Patent Trials and Appeal Board (“Board”) that assignor estoppel did not bar Arista Networks (“Arista”) from attempting to invalidate a patent belonging to Cisco Systems (“Cisco”). Arista’s founder, Dr. David Cheriton, was the inventor on the patent Arista wanted to invalidate and had previously assigned the patent to Cisco while employed by Cisco. See Arista Networks, Inc. v. Cisco Sys., Nos. 2017-1525, 2017-1577, 2018 (Fed. Cir. Nov. 9, 2018) (Before Prost, Schall, and Chen, J.) (Opinion for the court, Prost, J.).