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Sarepta faces another gene therapy hiccup as Regenxbio sues over Jim Wilson's patent

It turns out a regulatory delay isn’t the only bump on Sarepta’s road to gene therapy glory.

The biotech is being sued by Regenxbio, which is alleging that its slate of gene therapy programs, including two for Duchenne muscular dystrophy and limb-girdle muscular dystrophy infringes on a patent originally owned by the University of Pennsylvania.

The lawsuit, which was first reported by Bloomberg Law, adds another wrinkle as Sarepta strives to stay in the lead in a race to deliver the first genetic fix for Duchenne muscular dystrophy. After making its name with two antisense drugs — neither of which has been proven to have an effect against the crippling disease — the Cambridge, MA-based biotech has been viewed as the frontrunner versus Pfizer and trouble-prone Solid Bio. Roche was impressed enough to pay $1.15 billion to acquire ex-US rights to the program.


But Regenxbio wants Sarepta to stop stepping on their patents — and pay up. The biotech, which is now based in Rockville, MD, is seeking damages for past, present and/or future infringement equaling “no less than a reasonable royalty.”


At the center of the dispute is US Patent No. 10,526,617. Jim Wilson, the gene therapy luminary who co-founded Regenxbio, was cited as an inventor on that patent, granted this January.

As it covers a cultured host cell containing a recombinant nucleic acid molecule encoding the capsid protein, the technology can be used to create adeno-associated vectors — both in animal studies and for delivering a transgene into humans.

“The vectors made using the claimed subject matter of the ’617 Patent have unique properties, e.g., an ability to target certain types of cells in the body,” the lawsuit states.

Specifically, Regenxbio alleges, Sarepta’s Duchenne program — SRP-9001 — is manufactured by a process that includes making and using a cultured host cell a recombinant nucleic acid molecule encoding an AAVrh74 vp1 capsid protein. The same capsid protein is also integral to SRP-9003, the limb girdle candidate, and a host of other follow-on gene therapies.


Regenxbio is suing as Sarepta is sorting out a new request from regulators that can push back its pivotal study for Duchenne. While CEO Doug Ingram assured investors that quality control issues such as this are not uncommon and pinned the delay on an overburdened FDA, he stopped short of promising concrete timelines.

Focused on retinal, metabolic and neurodegenerative diseases for its internal pipeline, Regenxbio is perhaps more accomplished as a gene therapy tech provider. Novartis and Abeona have both licensed its NAV tech platform.

It also doesn’t shy away from legal actions. In its most recent quarterly report, Regenxbio disclosed that Abeona failed to make a $8 million payment due in April, effectively terminating their licensing agreement. In response to an arbitration claim Abeona filed in May “alleging we breached certain responsibilities to communicate with Abeona regarding our prosecution of licensed patents,” Regenxbio filed a counterclaim to ask for $28 million — including $20 million that would have been owed under the pact.

Last November Regenxbio challenged the FDA’s “arbitrary and capricious” decisions to issue a full clinical hold on its diabetic retinopathy trial and a partial hold on wet age-related macular degeneration. The company had withdrawn the IND for diabetic retinopathy, and the FDA lifted the partial hold for wet AMD two months later.