U.S. biotech Sarepta loses bid to challenge rival's muscular dystrophy patents

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REUTERS/Andrew Kelly

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  • Agreement with Nippon Shinyaku prevented administrative board challenges, appeals court finds
  • Companies have competing drugs for Duchenne muscular dystrophy

(Reuters) - A Japanese drug maker's patents related to treating Duchenne muscular dystrophy cannot be challenged by U.S. rival Sarepta Therapeutics before an administrative tribunal, a U.S. appeals court ruled Tuesday.

An agreement that Sarepta signed with Nippon Shinyaku while discussing a potential collaboration should have prevented Sarepta from asking the U.S. Patent and Trademark Office's Patent Trial and Appeal Board to review the patents, the U.S. Court of Appeals for the Federal Circuit said.

The appeals court reversed a decision by Delaware District Judge Leonard Stark, whom President Biden nominated to the Federal Circuit in November, and ordered him to stop Sarepta from continuing with the board proceedings.

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Shinyaku signed a confidentiality agreement with Cambridge, Massachusetts-based Sarepta in 2020. The agreement prevented the parties from filing patent lawsuits and validity challenges while it was in effect, until June 2021, and required any U.S. patent disputes within two years after it ended to be brought in Delaware federal court.

Shinyaku sued Sarepta in Delaware in July, alleging Sarepta breached their contract by filing seven petitions at the Patent Trial and Appeal Board. Sarepta challenged Shinyaku patents related to its Viltepso treatment for Duchenne muscular dystrophy, a rare genetic disorder that causes muscle deterioration.

Sarepta has its own treatment for the same disease called Vyondys. Both have received accelerated approval from the U.S. Food and Drug Administration.

Shinyaku asked the court to block Sarepta from continuing with the board proceedings and force it to withdraw the petitions.

Stark rejected Shinyaku's request, and said it would be "odd" for the agreement to block patent reviews to the extent that they became "time-barred and never available."

But Circuit Judge Alan Lourie wrote Tuesday that the plain language of the agreement required the companies' patent disputes to be settled in Delaware, including fights over patent validity.

The appeals court also said Shinyaku would suffer irreparable harm unless the board proceedings were barred, and that allowing them to continue could give Sarepta "multiple bites at the invalidity apple, including in a forum it bargained away."

Sarepta could still challenge the patents in Delaware, Lourie said.

Circuit Judges Pauline Newman and Kara Stoll joined the opinion.

The companies and their attorneys didn't immediately respond to requests for comment.

The case is Nippon Shinyaku Co v. Sarepta Therapeutics Inc, U.S. Court of Appeals for the Federal Circuit, No. 21-2369.

For Shinyaku: William Peterson of Morgan Lewis & Bockius

For Sarepta: Michael Flibbert of Finnegan Henderson Farabow Garrett & Dunner

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Blake Brittain reports on intellectual property law, including patents, trademarks, copyrights and trade secrets. Reach him at blake.brittain@thomsonreuters.com