Federal Circuit Decision: Assignor Estoppel Has No Place in IPR Proceedings

On November 9, 2018, in Arista Networks, Inc. v. Cisco Systems, Inc., the Federal Circuit held that assignor estoppel does not apply in inter partes review (IPR) proceedings. In this case, a former employee of Cisco Systems, Inc. (“Cisco”), who had assigned his invention as patented (U.S. Patent No. 7,340,597 – “the ‘597 patent”) to Cisco, …