FDA approves $2.1m gene therapy for infants with rare genetic disease

The Food and Drug Administration (FDA) has issued its first approval for a gene therapy treatment targeting young children. The gene therapy is called Zolgensma, and it is designed to treat the rare genetic disease spinal muscular atrophy in children under the age of two. The FDA's Acting Commissioner Ned Sharpless called the approval a 'milestone' for gene therapy.

Spinal muscular atrophy (SMA) is the rare result of a genetic mutation involving the survival motor neuron 1 gene. In the most common (and severe) cases, SMA onset starts during infancy, with symptoms appearing by the age of only six months old. The motor neuron problems caused by SMA result in severe complications, including trouble breathing and swallowing.

As a result of the damage to essential functions caused by motor neuron death, infants with SMA typically do not live past their early childhood years. The gene therapy Zolgensma potentially improves the outcome for these individuals, and as such has been approved for use in kids younger than 2 years old by the FDA. At $2.125 million over five years, this is officially the most expensive drug in the world.

According to the FDA, Zolgensma was demonstrated as safe and effective in both ongoing and completed clinical trials involving 36 infants suffering from SMA. Results from the treatment of 21 of those patients offer 'primary evidence of effectiveness,' the FDA said in a statement today, explaining that 13 of the remaining 19 patients have reached at least 14 months of age.

As well, these patients experienced 'significant improvement in their ability to reach developmental motor milestones' when compared to other infantile-onset SMA patients who didn't receive the treatment. The drug can cause vomiting, elevated liver enzymes, and 'acute serious liver injury,' the Administration says.

According to Novartis, the company behind the treatment, the huge $2.1 million one-time treatment cost will be spread over a 5-year payment period at $425,000 per year. The company is in 'advanced discussions' with 15+ insurance companies over payment options for the treatment.