The inter partes review (IPR) statute includes an estoppel provision that precludes an IPR requester from asserting any ground of invalidity that the requester raised or reasonably could have raised during the IPR, in a subsequent civil action, or ITC proceeding. 35 U.S.C. § 315(e)(2). Consequently, courts routinely grant stays of litigation when the defendant/movant is subject to the full extent of estoppel mandated by § 315. But the landscape of decisions on stay motions is less clear when the movant relies on an IPR petition filed by another who is not a party to the same litigation.
