Supernus Pharmaceuticals has beaten back a challenge from generic drugmaker Amneal Pharmaceuticals over the validity of three patents for its skin treatment Oracea, through a favorable ruling from the board created three years ago to hear postgrant proceedings following the overhaul of U.S. patent law.

The U.S. Patent Trial and Appeal Board (PTAB) ruled that three patents held by Supernus Pharmaceuticals for Oracea do not have obvious claims as asserted by Amneal, and thus are valid.

The decisions were the first upholding pharma patents following an inter partes review under the “Hatch-Waxman Act,” formally known as the Drug Price Competition and Patent Term Restoration Act of 1984. The law was designed to encourage generic drug development in hopes of lowering treatment prices through competition.

The alternative to the inter partes review would have been a U.S. District Court lawsuit. PTAB uses a lower “preponderance of evidence” standard compared with the “clear and convincing” evidence of patent invalidity required by District Court. That difference has prompted retired Chief Judge of the Federal Circuit Randall Rader to label the PTAB “a death squad for patents.”

“The question was, could the same family of patent claims be upheld under a lesser standard, over substantially the same art. And happily, the answer is yes,” Gerald Flattmann, a partner with the law firm Paul Hastings, told GEN.

Despite the Supernus patents being upheld by the PTAB, Flattmann added: “It is still a challenging venue to deal with. As a pharmaceutical client in particular, you need to navigate this carefully. You need to think about this at the early stages, and truly decide what arguments could possibly win,” he added.

“In this appeal, it was very helpful to delve deeply into the facts, given that the Patent Board is technical in nature,” Flattmann explained. “The other thing I noticed is that perhaps it’s useful to think about your procedural grounds at the same time that you’re working your substantive grounds. The Patent Office will pay attention to those, and perhaps will put more weight on the substantive grounds, if you raise other issues.”

The PTAB decisions—issued separately for each patent—can be appealed to the U.S. Court of Appeals for the Federal Circuit (CAFC). Amneal told Bloomberg it would not comment on the decisions.

The PTAB was created under the Leahy-Smith America Invents Act of 2011 to replace the former Board of Patent Appeals and Interferences in hearing a category of patent challenges called inter partes reviews allowing third-party challenges after a patent has been granted but limits the basis of such review to prior art consisting of patents and printed publications.

Galderma had prevailed earlier against another generic drug maker, Mylan, in a District Court challenge to the same patent family. The court found that prior art had not made the drug obvious, a decision upheld by the CAFC. Flattmann represented Galderma and Supernus in that case.

The patents under review are set to expire between 2024 and 2025.