Novartis reported that two patients have died because of acute liver failure following treatment with Zolgensma, the company's gene therapy used to treat spinal muscular atrophy.
The cases took place in Russia and Kazakhstan after a Zolgensma infusion and following the initiation of a corticosteroid taper intended to fight liver complications, according to an Aug. 11 news release from Novartis.
The company said it has notified health authorities, including the FDA, and informed relevant healthcare professionals.
"While this is important safety information, it is not a new safety signal and we firmly believe in the overall favorable risk/benefit profile of Zolgensma, which to date has been used to treat more than 2,300 patients worldwide across clinical trials, managed access programs and in the commercial setting," the release said.
SMA is a rare genetic disease that leads to progressive muscle weakness and, in some cases, paralysis. The FDA approved Zolgensma for children younger than 2. It replaces the defective or missing SMN1 gene to halt disease progression with a single one-time infusion, administered to patients over one hour.
Zolgensma was developed by AveXis, a biotechnology company acquired by Novartis for $8.7 billion in 2018.