(Reuters) - Novartis AG on Thursday reported two patient fatalities due to acute liver failure following treatment with Zolgensma gene therapy used to treat spinal muscular atrophy.
The company has notified health authorities in markets where the drug is sold, including the FDA, and has informed relevant healthcare professionals as an additional step.
"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," Novartis said in a statement.
The two fatal cases of acute liver failure took place in Russia and Kazakhstan after 5 to 6 weeks of Zolgensma infusion and about 1-10 days following the initiation of corticosteroid taper, it reported.
Novartis' Zolgensma, that won conditional EU approval during early 2020, costs more than $2 million per patient.
(Reporting by Sneha Bhowmik and Ankur Banerjee in Bengaluru; Editing by Stephen Coates)