Novartis Says Two Children Getting Spinal Atrophy Drug Have Died

Two children who received Zolgensma, Novartis AG’s gene therapy for a rare condition called spinal muscular atrophy, died from liver complications.

The children died from acute liver failure about six weeks after receiving the infusion of Zolgensma and one to 10 days after tapered doses of a steroid that’s meant to combat liver complications, Novartis said in an emailed statement Thursday. The deaths occurred in Russia and Kazakhstan.

Liver toxicities have dogged genetic treatments, and regulators had warned that Zolgensma could cause serious and potentially lethal liver complications. These are the first two instances of death from acute liver …