The price of challenging a patent in an IPR or post-grant review is often said to include estoppel that would block, at a minimum, other challenges at the Patent Office to any claims for which a final written decision is issued by the Board. We recently commented on a potential exception to this rule. A further exception is being debated in International Business Machines Corporation v. Intellectual Ventures II LLC, IPR2014-01465 (Paper 29).

In that case, the Board is being asked to determine the effect of a final written decision confirming claims being challenged in a second, still pending IPR trial. The applicable rule states that the same petitioner may not “maintain” another proceeding once a final written decision is issued. The patent owner seeks to have the trial previously instituted (based on a second petition) entirely terminated. However, its motion also addresses the possibility that the trial might not end, but that the petitioner would just be excluded from further participating in the trial. As trial in the second IPR is nearly over, scheduled for an oral hearing just days after the decision in the first IPR, precluding the petitioner from further participation in the trial might nonetheless allow the Board to render a decision based on the petitioner’s already submitted evidence and briefing. Thus, the meaning of “maintaining” a proceeding  once estoppel applies has the potential to significantly impact the outcome in this case.

The Board’s ruling is likely to provide greater clarity around the effects and limits of estoppel following an unsuccessful challenge in an IPR. Accordingly, it should be watched and factored into strategic decisions for petitioners who file, or would like to file, multiple challenges against the same claims of a patent. Patent owners similarly need to watch this case, to appropriately determine how to deal with multiple challenges to a patent.