35 USC §315(e)(2) prohibits a petitioner (or real party in interest or privy of the petitioner) in an Inter Partes Review (IPR) of a patent claim from asserting in district court litigation that “the claim is invalid on any ground that the petitioner raised or reasonably could have raised
” during the IPR proceeding. This statutory IPR estoppel attaches as soon as the Patent Trials and Appeals Board (“PTAB”) renders a final written decision in an IPR proceeding.
Although the PTAB has issued over 200 final written IPR decisions triggering estoppel in a parallel district court action since the introduction of the process in 2012, there is yet to be seen any real guidance from the district courts as to what constitutes a ground that “reasonably could have” been raised by a petitioner. Despite the lack of case law on what “reasonably could have” been raised means, we do have some guidance available to us outlining relevant exceptions to the could-have-raised estoppel.
For additional analysis, including grounds that have been determined to be likely possibilities for a petitioner to raise in a subsequently filed district court proceeding if omitted from the IPR, please click here.