The ground shook for Sarepta Therapeutics, Inc. (NASDAQ:SRPT) last week as the U.S. Food and Drug Administration (FDA), alarmed by a third patient death tied to its gene therapy platform, pulled a rare move: requesting a voluntary halt to Elevidys shipments.

U.S. regulators asked Sarepta Therapeutics on Friday to voluntarily halt shipments of its Elevidys gene therapy after a muscular dystrophy patient who received a different, experimental treatment died,

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.