Congress Intended For Assignors to Challenge Patents in IPRs
In Arista Networks v. Cisco Systems, the Fed. Cir. affirmed the PTABs decision to reject assignor estoppel in IPRs. Assignor estoppel bars a patent's seller from attacking the patent's validity in subsequent patent infringement litigation. In Diamond Scientific Co. v. Ambico, Inc., the Fed. Cir. distinguished the policies applicable to assignor estoppel from those applicable to licensee estoppel. It therefore held that the doctrine of Lear v. Adkins, which applies to licenses and holds that public policy requires that licensees not be muzzled from challenging the validity of possibly spurious patents, does not apply to assignments.
The inventor had assigned his rights to Cisco, then left Cisco and co-founded, petitioner, Arista Networks. The assignor agreed “generally to do everything possible to aid said assignee, their successors, assigns and nominees, at their request and expense, in obtaining and enforcing patents for said inventions in all countries. The Board reasoned that 1) Congress provided a broad grant to challenge patentability in IPRs and 2) Congress had not expressly provided for assignor estoppel. In rejecting Cisco’s argument that assignor estoppel is a well-established common-law doctrine, the Fed. Cir. cited evidence of a statutory purpose to the contrary. Citing the statutory language of 311(a) that A person who is not the owner of a patent may filed … an IPR, the Fed. Cir. found the plain language unambiguous. Any inconsistencies in forums was interpreted as Congressional intent. Perhaps assignments should contract for assignor estoppel in IPRs.