The Food and Drug Administration won’t sign off on Sarepta Therapeutics Inc. bringing its controversial gene therapy back to the market until the company can persuade US regulators that it won’t cause more deaths,

The regulator had asked Sarepta Therapeutics to halt all shipments of its therapy, Elevidys, after three patients died from liver failure after taking it or a similar treatment.

The commercial and clinical use of Elevidys was discontinued after two fatal cases of acute liver failure.

Children’s Hospital Los Angeles paused the use of Sarepta Therapeutics Inc.’s gene therapy for Duchenne muscular dystrophy in the wake of rising safety concerns about liver toxicity, adding to mounting challenges for the drugmaker.

Sarepta Therapeutics faces an "arduous path” to try to get its gene therapy for Duchenne muscular dystrophy back onto the market, a senior FDA official told STAT.