Drugmaker Sarepta Therapeutics says it won’t comply with a request from U.S. regulators to halt all shipments of its gene therapy.

The agency also revoked Sarepta's platform technology designation for AAVrh74 Friday and issued a safety communication saying the agency was investigating the three deaths due to acute liver failure following treatment with Sarepta's AAVrh74 gene therapies.

The company refused the FDA’s request and will continue shipping its therapy, Elevidys, to Duchenne patients who can still walk. A pause on shipments to older, non-ambulatory patients remains in place.