Estoppel under the AIA: Considerations for Strategic Use of 'Redundant' IPR Grounds

摘要

Inter partes reviews (IPRs) are a powerful tool to challenge the validity of issued patent claims before the U.S. Patent Trial and Appeal Board (PTAB). One of the risks to a petitioner in filing an IPR is that if an IPR reaches a final written decision and at least one of the challenged claims is upheld as patentable, the petitioner is estopped from presenting invalidity arguments in district court or later PTAB proceedings "with respect to that claim on any ground that the petitioner raised or reasonably could have raised during that inter partes review."