The United States Court of Appeals for the Federal Circuit [official website] ruled [opinion, PDF] on Friday that tribal sovereign immunity cannot be claimed to prevent the validity of a patent from being decided by Inter Partes Review (IPR) proceedings by the United States Patent and Trademark Office (USPTO) [official website].

The case arose when Allergan sued Mylan, Teva, and Akorn in 2015 for violating patents related to its Restasis dry eye treatment. Mylan petitioned for IPR in June 2016, at which point Mylan transferred the patents to the Saint Regis Mohawk Tribe. The tribe then claimed tribal immunity.

The court found that tribal sovereign immunity does not apply to IPR because the process is “more like an agency enforcement action than a civil suit brought by a private party.” This was decided based on several factors, including that the USPTO director has discretion when deciding when to institute a review, the review can continue even if the parties drop out of the proceedings, and the IPR proceedings do not mirror the Federal Rules of Civil Procedure.

The tribe had acknowledged that tribal immunity would not apply to ex parte or inter partes reexaminations. The court found that the US Supreme Court had previously found that inter partes reexamination and IPR have the same “basic purposes, namely to reexamine an agency decision.”

The court also specified that the decision does not address the question of if state sovereign immunity would apply, but noted that “there are many parallels” with tribal immunity.

The US Supreme Court ruled [JURIST report] in April that the IPR was constitutional and did not violate Article III or the Seventh Amendment of the Constitution. The US House of Representatives Courts, Intellectual Property, and the Internet Subcommittee held hearings [JURIST report] in November regarding the case.