A federal judge in Delaware has declined to dismiss a lawsuit by RegenxBio and the University of Pennsylvania charging that Sarepta Therapeutics infringed on their patent for a type of cultured host cells during its development of muscular dystrophy gene therapies.

Sarepta argued that its use of the patent was related to a biologics license application to the FDA for the therapies and therefore its use of the cells is protected under the safe harbor patent exemption in the Hatch-Waxman Act.

But Judge Richard Andrews of the U.S. District Court for the District of Delaware found the safe harbor protections don’t apply because the patented products in question “are not subject to FDA premarket approval.”