Sarepta Faces Mixed Results in Patent Challenges Against Genzyme's Gene Therapy Analytical Methods
Key Insights
The U.S. Patent and Trademark Office issued mixed decisions on Sarepta Therapeutics' patent challenges against Genzyme, denying institution of three inter partes review proceedings while granting one related to gene therapy analytical methods.
The patent disputes involve analytical ultracentrifugation and liquid chromatography/mass spectrometry methods for characterizing adeno-associated virus (search) particles used in gene therapy products including Elevidys®.
These patent challenges are part of ongoing litigation between the companies, with Sarepta reporting $898.7 million in net revenue from Elevidys® in 2025.
The U.S. Patent and Trademark Office has issued a series of mixed decisions on patent challenges filed by Sarepta Therapeutics against Genzyme, with the majority of inter partes review (IPR) proceedings being denied institution while one was granted. The disputes center on analytical methods used to characterize adeno-associated virus (search) particles in gene therapy products, including Sarepta's Elevidys® (delandistrogene moxeparvovec-rokl (search)).
Patent Challenge Outcomes
On May 6, 2026, the USPTO Director issued decisions on two IPR proceedings. In IPR2026-00149, Sarepta challenged U.S. Patent No. 12,013,326, which covers methods for characterizing recombinant adeno-associated virus (search) (rAAV (search)) particles using analytical ultracentrifugation. The Director denied institution on the merits, finding that Sarepta had not demonstrated a reasonable likelihood of prevailing with respect to at least one challenged claim.
However, in IPR2026-00150, the Director granted institution for Sarepta's challenge against U.S. Patent No. 12,031,894, which relates to similar analytical ultracentrifugation methods for characterizing rAAV (search) particles. The Director determined that the petition demonstrated a reasonable likelihood that at least one challenged claim is unpatentable.
Additional Denials
On May 15, 2026, the USPTO Director issued summary institution decisions denying two additional IPR proceedings on the merits. In IPR2026-00167, Sarepta challenged claims 1-20 of U.S. Patent No. 11,698,377, which covers methods for determining the serotype of adeno-associated virus (search) (AAV) particles using liquid chromatography/mass spectrometry (LC-MS) intact protein analysis.
Similarly, IPR2026-00168, which challenged claims 1-21 of U.S. Patent No. 12,123,880 relating to LC-MS methods for analyzing and characterizing AAV particles and viral proteins, was also denied institution.
Ongoing Legal Proceedings
All patents involved in these IPR proceedings are assigned to Genzyme. The patent challenges are connected to ongoing litigation between the parties, including Case No. 24-cv-00882 in the District of Delaware. An additional IPR filed by Sarepta against Genzyme's U.S. Patent No. 12,298,313 (IPR2026-00270) remains pending an institution decision.
Financial Context
The patent disputes occur against the backdrop of significant commercial success for Elevidys®, with Sarepta reporting $898.7 million in net revenue from the gene therapy product in 2025. The analytical methods covered by these patents are crucial for the characterization and quality control of gene therapy products, making the intellectual property landscape particularly important for companies operating in this space.