Multidefendant patent litigations are becoming more common. Kyle Jensen, “Counting Defendants in Patent Litigation,” Patently-O Blog (Oct. 27, 2010), (noting that, although the number of cases has remained stable in recent years, the number of defendants has increased). Defendants in such litigations often form joint defense groups, and an issue that frequently arises is what, if any, estoppel effects there will be to the members of a joint defense group if one member requests inter partes re-examination of the patent(s) at issue. Specifically, will the nonrequesting defendant members be subject to estoppel either during the litigation or during future proceedings before the U.S. Patent and Trademark Office?
Whether to request inter partes re-examination during litigation is beyond the scope of this article, but such requests are certainly on the rise. See USPTO report (indicating that the number of requests is increasing every year and that 70% are “known to be in litigation”). Some benefits of inter partes re-examination are that the process is subject to a lower burden of proof, see In re Etter, 756 F.2d 852 (Fed. Cir. 1985); is less expensive; may warrant a stay of the litigation; and is statistically more likely to result in one or more independent claims being invalidated or narrowed. See Steven I. Weisburd & Andrew A. Phillips, “Reexamination and Its Interplay with Litigation,” Paper Distributed at IPO Annual Meeting, 4, 16 (Sept. 12-14, 2010) (noting that both inter partes re-examination and litigation have about a 50% chance of all claims being found invalid, but that in inter partes re-examination there is a 92% chance that at least one independent claim will be found invalid or narrowed).
