The last couple of weeks has been particularly distressing for Duchenne muscular dystrophy patients and their families. The fate of Sarpeta’s gene therapy for the disease, called Elevidys, has been the center of a dizzying saga that seems to change by the minute.

Sarepta's therapy has been under scrutiny from regulators after two teenage boys died earlier this year from acute liver injury, a known side effect of the treatment. The FDA then requested a pause in shipments of the drug after the death of a third patient taking a different Sarepta therapy.

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.