A second patient receiving its experimental gene therapy Elevidys has died from liver failure, raising serious questions on the drug’s outlook.

Shares of Sarepta Therapeutics have plunged again after the drugmaker reported a second death in connection with its gene therapy for muscular dystrophy.

The death of a boy with Duchenne muscular dystrophy, tied to a gene therapy, is above all a tragedy. But it is also undermining investor confidence in the company that makes it.