A lower court had previously ruled for Sarepta in the companies’ long-running dispute, finding that REGENXBIO’s AAV patent was invalid because its elements were naturally occurring. The appeals court on Friday said that this original decision adopts a “narrow” view of the invention.
An appellate court has ruled in favor of REGENXBIO in a years-long patent spat with Sarepta Therapeutics over a core technology that the latter used for its Duchenne muscular dystrophy gene therapy.
The decision overturns that of a lower court, which in January 2024 ruled in favor of Sarepta and found that REGENXBIO’s patent was invalid because its elements were naturally occurring.
“The claims here are not merely directed to repackaging products of nature,” Judge Kara Stoll wrote in her ruling on Friday.
REGENXBIO’s technology “fundamentally [creates] a cell containing a molecule that could not form in nature on its own,” the judge wrote. The lower court’s decision, Stoll continued, “takes too narrow a view of the asserted claims by focusing on whether the individual components of the claim were markedly different from what is naturally occurring and failing to consider whether the claimed composition as a whole was ‘not naturally occurring.’”
REGENXBIO—alongside the University of Pennsylvania, which owns the patent under contention and licenses it to the biotech—filed its lawsuit in September 2020, alleging that Sarepta used a protected adeno-associated virus (AAV) vector platform for the gene therapy that would eventually become Elevidys, which was approved in June 2023 for Duchenne muscular dystrophy.
In January 2024, a Delaware district court ruled in favor of Sarepta and found that REGENXBIO’s patents were invalid. The technology in question, the court said at the time, consisted of several naturally occurring components, none of which had been changed, rendering the invention unpatentable.
Stoll has reversed this ruling and returned it to the lower court for reconsideration. “We have considered Sarepta’s remaining arguments and find them unpersuasive,” she wrote on Friday.
The court decision comes after a series of setbacks for REGENXBIO. Earlier this month, the FDA’s three-month review extension for the company’s Hunter syndrome gene therapy ended in rejection, with the agency questioning the applicability of using natural history controls in RGX-121’s pivotal study.
In January, the regulator slapped a clinical hold on REGENXBIO’s gene therapy for Hurler syndrome after one treated patient developed a tumor. The hold also extended to RGX-121.
For Sarepta, meanwhile, Stoll’s ruling adds to its Duchenne difficulties. Last year, the biotech reported two deaths associated with Elevidys, leading the company to pivot from gene therapy to an siRNA-focused pipeline. The FDA has also since added a black box warning to Elevidys and narrowed its patient pool.
