Sarepta Hits Fresh Hurdle As Court Revives Patent Lawsuit With Regenxbio Over Muscular Disorder Therapy

While Sarepta’s gene therapy for the treatment of DMD called Elevidys was approved by the FDA in 2023, Regenxbio is developing its treatment.

• Regenxbio filed a lawsuit in 2020 alleging that Elevidys infringed a gene-therapy patent that the company licenses from University of Pennsylvania.
• The U.S. Court of Appeals for the Federal Circuit on Friday reinstated the lawsuit between the two companies. 
• The rekindling of the case marks a new hurdle for Sarepta who has been embroiled in regulatory scrutiny over the past few months owing to the death of two patients treated with its gene therapy.

The U.S. Court of Appeals for the Federal Circuit has reportedly reinstated the patent lawsuit between Regenxbio (RGNX) and Sarepta Therapeutics (SRPT) regarding the latter’s Duchenne muscular dystrophy (DMD) treatment.

According to a Reuters report, the court reversed a Delaware federal judge's ruling that had invalidated the patent at issue.

Both Sarepta and Regenxbio are developing or have developed treatments for DMD. Duchenne muscular dystrophy (DMD) is a severe, progressive genetic disorder primarily affecting young boys, causing muscle degeneration due to a lack of dystrophin protein. Symptoms include weakness in the legs/pelvis, frequent falls, and enlarged calves.

While Sarepta’s gene therapy for the treatment of DMD called Elevidys was approved by the U.S. Food and Drug Administration in 2023, Regenxbio is developing its treatment. Regenxbio filed a lawsuit in 2020 alleging that Elevidys infringed a gene-therapy patent that the company licenses from University of Pennsylvania.

Regenxbio and Penn have requested more than $900 million in damages in the case, the report noted.

New Hurdle For Sarepta

The rekindling of the case marks a new hurdle for Sarepta who has been embroiled in regulatory scrutiny over the past several months. In 2025, Elevidys created safety concerns following the death of two patients after treatment. Both non-ambulatory patients suffered from acute liver failure.

While Sarepta resumed shipments to DMD patients who can walk after a temporary pause, it is now developing a risk-mitigation approach for patients who cannot walk to resume shipments in the particular patient segment. According to the company’s preliminary estimates, revenue from Elevidys for the full year 2025 is expected to come to $898.7 million.

How Did Stocktwits Users React?

On Stocktwits, retail sentiment around RGNX and SRPT stocks trended in the ‘bearish’ territory at the time of writing.

While RGNX shares gained 11% over the past 12 months, SRPT stock fell 83%. 

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