A unanimous three-judge panel of the Patent Trial and Appeal Board (PTAB) ruled on Friday, February 23, 2018 (Decision), that the doctrine of tribal immunity does not apply, as a non-statutory defense, to inter partes review (IPR) proceedings before the US Patent and Trademark Office.1

The Decision is the most recent development in the intensely watched battle between Allergan and generic challengers Mylan, Teva and Akorn2 over Allergan’s Restasis® dry eye medication. The validity of six US patents asserted by Allergan has been challenged by the generic drug companies in IPR proceedings.3 Less than one-week before scheduled final hearing in the IPRs back in September 2017, the St. Regis Mohawk Tribe (Tribe) informed the PTAB of its recently acquired ownership of the challenged patents, and its intention to file a “motion to dismiss” the proceedings based upon the Tribe’s sovereign immunity. Friday’s Decision by the PTAB denies the Tribe’s motion to terminate the proceedings, which will now presumably proceed to a final written decision on the merits.

In its broadest respects, the Decision found that the doctrine of tribal immunity does not apply to IPR proceedings. The panel noted that inter partes review was statutorily authorized by Congress, and as held by the US Supreme Court, general acts of Congress are applicable to Indian tribes absent clear and convincing indications to the contrary.4 The PTAB found no reason for an exception to this general principle.5 The panel further asserted that inter partes review proceedings are not the type of “suit” from which an Indian tribe would traditionally enjoy immunity under the common law.6

The fact that the PTAB does not exercise personal jurisdiction over the patent owner (in this case the Tribe), or compel the patent owner to appear or participate in the proceedings, was cited in support of this finding.7 However, the panel drew an interesting distinction between inter partes review, which was characterized as solely an assertion of jurisdiction over the patent claims8, and patent interference proceedings which involve a determination of the rights of adverse parties concerning priority of inventorship rights. The explicit recognition of this distinction leaves open the possibility that tribal immunity could be a valid defense in increasingly rare interference proceedings. It also leaves open the question as to whether tribal immunity could be asserted as a viable defense in derivation proceedings before the PTAB. Derivation proceedings provide a means to establish that a patent applicant (or patentee) was not an inventor, but rather that they derived the invention from someone else.

The PTAB was, however, careful not to characterize inter partes review as an in rem proceeding9, specifically noting the pending US Supreme Court decision in Upper Skagit Indian Tribe v. Lundgren10 that is expected to addresses the issue of whether the exercise of in rem jurisdiction defeats an assertion of sovereign tribal immunity.

According to a second prong of the decision, the PTAB asserted rather broadly that even if the doctrine of tribal immunity were applicable to inter partes review, its assertion does not serve as a basis to terminate trial.11 This is because, according to the panel, a patent owner’s participation in the trial is not required, citing multiple cases where trials proceeded to a final written decision without participation from a patent owner.12 Thus, the PTAB reasoned that even if the Tribe were to be dismissed, this should not result in termination of the proceedings.

Applying this broadly characterized assertion, the Decision goes on to hold that the terms of the license between Allergan and the Tribe transferred “all substantial rights” in the challenged patents back to Allergan, thus Allergan is still a “patent owner.”13 Because Allergan was still deemed to be a patent owner, it can continue to participate in the proceedings even if the Tribe does not. The PTAB examined various terms of the agreements (e.g., rights to sue for infringement; rights to make, use and sell covered products; rights to sublicense; rights to litigation/licensing proceeds, etc.) between Allergan and the Tribe in reaching its conclusion. Thus, the panel set forth a third, and more narrow and fact-driven reason, for denying the Tribe’s motion to terminate the IPR proceedings.

As an important backdrop, the constitutionality of inter partes review is currently being decided by the Supreme Court in the Oil States case.14 A finding of unconstitutionality by the Supreme Court could very well moot the entire debate.