When three patients die after taking a cutting-edge drug, most companies hit the brakes. Not Sarepta Therapeutics. The Massachusetts-based biotech company is under fire for refusing a request from the U.

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

At the FDA's request, delandistrogene moxeparvovec (Elevidys), the only approved gene therapy for Duchenne muscular dystrophy, will carry a black box warning for acute liver injury and acute liver failure, drugmaker Sarepta Therapeutics said.