In Russia and Kazakhstan, two children died while being treated for spinal muscular atrophy (SMA) with Zolgensma. According to the report of the developer of the drug, the Swiss pharmaceutical company Novartis, the cause of death was acute liver failure.

Death occurred after five to six weeks of infusion and one to ten days after starting to taper off corticosteroids (anti-inflammatory drugs), the report said.

The age of children and their data are not given.

SMA is a rare genetic disease that affects the motor neurons of the spinal cord. This leads to atrophy and muscle paralysis.

At the end of last year, Novartis received permission to use the drug in Russia. This is the most expensive drug in the world, it costs $2.125 million.

There are three drugs for SMA in the world: Spinraza, Risdiplam and Zolgensma. Only Spinraza and Risdiplam were previously registered in Russia. These drugs must be taken for life. The injection of "Zolgensma" is done only once, at the age of two years.