INSIGHTS

Petitioners should take care to conduct a thorough prior-art search when preparing an IPR petition to avoid overlooking references that reasonably could have been raised and compile evidence to support the position that their searching efforts were reasonably diligent, e.g., documenting prior-art search strategies and results.

How patent owners can carry their burden of proving that newly raised prior art would have been revealed by a diligent search remains to be seen from cases postIronburg.

Patent owners seeking to disqualify newly raised prior-art benefit from hindsight when assembling evidence to show that a diligent search would have discovered the prior art. Supporting evidence might include, for example, whether the prior-art was found in connection with other related patent proceedings, the details of prior-art searches conducted by parties and results, and opinions from prior-art search firms on what a reasonable search strategy would entail and reveal.

Ironburg specifically addressed estoppel in district court proceedings following an IPR under AIA Section 315(e)(2). As the same “reasonably could have raised” language appears in counterpart AIA Section 315(e)(1), concerning estoppel in USPTO proceedings following an IPR. The Patent Trial and Appeals Board will likely follow standards set forth in Ironburg in connection with AIA Section 315(e)(1).