The recent PTAB order in IPR2017-01427 is a cautionary tale for petitioners considering multiple IPRs against a single patent. On May 11, 2017, Facebook and WhatsApp filed the ’1427 IPR petition challenging claims 1-8 of U.S. Patent 8,995,433. The PTAB instituted the ’1427 IPR on December 4, 2017, and LG Electronics later joined the IPR. Previously, Apple had filed a separate challenge to the ’433 patent in IPR2017-00225, instituted on May 25, 2017, challenging claims 1-6 and 8 of the ’433 patent. On June 16, 2017, subsequent to filing the ’1427 IPR petition, Facebook and WhatsApp filed another IPR petition and requested joinder with the ’225 IPR. The joinder was granted. Thus, Facebook and WhatsApp were petitioners in two separate IPRs challenging the ’433 patent—the ’1427 IPR (challenging claims 1-8) and the ’225 IPR (challenging most of the same claims: 1-6 and 8).

The troubles for Facebook and WhatsApp began when the PTAB issued a final written decision in the ’225 IPR, because, under the AIA:

[t]he petitioner in an inter partes review of a claim in a patent under this chapter that results in a final written decision under section 318(a), or the real party in interest or privy of the petitioner, may not request or maintain a proceeding before the Office with respect to that claim on any ground that the petitioner raised or reasonably could have raised during that inter partes review

35 U.S.C. § 315(e)(1). Since Facebook and WhatsApp had joined the ’225 IPR, they were “petitioner[s] in an inter partes review … result[ing] in a final written decision” as to claims 1-6 and 8 of the ’433 patent. The PTAB thus considered whether they could maintain the ’1427 IPR.

The PTAB first considered whether the invalidity grounds raised in the ’1427 IPR were “raised or reasonably could have been raised” in the ’225. The PTAB reasoned that, since the ’1427 IPR petition predated their ’225 IPR joinder petition, Facebook and WhatsApp must have been aware of the invalidity grounds raised in the ’1427 IPR at the time they filed the ’225 joinder petition. Therefore, the PTAB held, those invalidity grounds indeed could have been raised in the ’225 joinder petition. As such, Facebook and WhatsApp were estopped from maintaining the ’1427 IPR as to claims 1-6 and 8. However, they were not estopped as to claim 7, because it was not challenged in the ’225 IPR.

The PTAB then addressed how the ’1427 petition would proceed. Because LG had joined the IPR, it was permitted to maintain its challenge to each of claims 1-8. However, Facebook’s and WhatsApp’s participation was limited to issues concerning claim 7, which was not part of the ’225 IPR final written decision.

This case illustrates the care that petitioners must undertake when filing (or joining) serial IPR challenges to a single patent. Consideration should be given to what will remain of a second (or third) IPR after a final written decision is issued in the first IPR.