Dive Brief:
- BioMarin Pharmaceutical on Wednesday said it plans to seek a review of a patent board ruling it lost to Sarepta Therapeutics earlier this week, extending a legal battle over Sarepta's formulations for its drugs to treat Duchenne muscular dystrophy (DMD).
- Cambridge, MA-based Sarepta, which just won approval of its DMD drug eteplirsen on Monday, announced Wednesday that the U.S. Patent Trial and Appeal Board (PTAB) had ruled in its favor over two composition of matter patents for exon 51- and exon 53-skipping treatment methods.
- BioMarin was one of several drugmakers whose proposed DMD medications were rejected by the Food and Drug Administration this year. Appeal of the patent rulings are a last attempt to claim Sarepta's eteplirsen infringes on BioMarin intellectual property.
Dive Insight:
Emotions may still be raw for BioMarin after the FDA passed over its DMD drug Kyndrisa despite support from by families whose kids are impacted by the disease, which is often fatal. DMD affects an estimated one in every 3,500 to 5,000 boys born worldwide.
After the FDA's rejection of Kyndrisa, BioMarin eventually dropped its Duchenne development program, discontinuing work on several pipeline candidates and withdrawing an application to European regulators for approval of Kyndrisa.
BioMarin isn't tipping its hand on how it plans to challenge the rulings in favor of Sarepta. "BioMarin is completing its review of the decision and the specific means it may use to seek a further review," the company said in a statement.
The battle over intellectual property rights between BioMarin and Sarepta involves the precise chemistry of Sarepta's drugs, specifically "composition of matter claims related to exon 51 skipping antisense oligonucleotides."
BioMarin did not comment on further details of its appeal plans.
In DMD, certain genetic mutations involve the deletion of exons which interrupt proper translation of the genetic code into protein. Skipping exon 51 is designed to fix mutations that cause the disease, and hopefully boost production of the dystrophin protein — the absence of which inhibits proper muscle function.
A previous 2015 PTAB decision had been decided in favor of BioMarin's claims over method of use patents on exon 51 skipping antisense oligonucleotides. That ruling is now under appeal at the Federal Circuit Court of Appeals and BioMarin expects a decision related to the method of use patent in late 2017 or early 2018, according to its statement.
“If BioMarin is successful in this appeal, it believes that [Sarepta’s] Exondys 51 would infringe the MOU patents,” BioMarin contends.
Sarepta, however, noted that BioMarin's method of use claims currently on appeal involve matters ruled "unpatentable" in Tuesday's PTAB decision.