FDA Approves SMA Gene Therapy

Novartis has set the price for Zolgensma (onasemnogene abeparvovec-xioi) at $2.12 million to be paid over a five-year period.


The U.S. Food and Drug Administration, as expected, has approved the new gene therapy Zolgensma (onasemnogene abeparvovec-xioi) for the treatment of pediatric patients less than two years of age with spinal muscular atrophy (SMA), including those that are presymptomatic at diagnosis, with specific genetic mutations. The drug was developed by AveXis, which was acquired by Novartis in 2018 for $ 8.7 billion.

SMA is the leading cause of death in infants attributable to genetic flaws. In the United States alone, approximately 450–500 infants are born with SMA each year. Worldwide, approximately 1 in 10,000 babies are born with SMA. Babies with SMA have a genetic defect in the survival motor gene 1 (SMN1 gene), which codes for the SMN protein, a protein necessary for survival of motor neurons. In the most severe cases rapid motor neuron loss and associated muscle deterioration lead to death by 24 months of age for more than 90% of patients


Zolgensma is a one-time treatment via intravenous (IV) infusion designed to address the bi-allelic mutations in the SMN1 gene by providing a functional copy of the human SMN gene.

The approval was based on the positive results of several clinical studies. The treated children not only survived, but in many cases were also able to sit, roll, crawl, play and, in a few cases, walk. More than 150 patients have been treated to date. The drug is currently under review in Europe under the Accelerated Assessment Procedure, where it has the PRIME (PRIority MEdicines) designation, and in Japan, where it has the accelerated Sakigake designation.


AveXis will market Zolgensma in the United States, providing comprehensive patient support through its OneGene Program. Until the drug receives approval elsewhere in the world, the company has arranged to make the treatment available in international markets, subject to local laws and regulations, as a part of its paid Managed Access Program via a collaboration with the third-party provider Durbin.


The one catch for this new, successful treatment is its very high price tag. Novartis will sell Zolgensma for $2.12 million per treatment, making it the most expensive drug ever placed in the U.S. market. With the high price tag, Novartis has also made provision for a five-year installment plan, with yearly payments at $425,000. Company executives have said the cost of the drug is still less than the current cost for treating children with SMA, which can be hundreds of thousands of dollars per year, over a period of 10 years.


There are, however, still questions about the length of time that the treatment is effective, since study data only extends to five years after treatment. There is no reason to believe the treatment will remain effective, but there is no data to confirm yet that follow-up treatments will not be necessary.



Emilie Branch

Emilie is responsible for strategic content development based on scientific areas of specialty for Nice Insight research articles and for assisting client content development across a range of industry channels. Prior to joining Nice Insight, Emilie worked at a strategy-based consulting firm focused on consumer ethnographic research. She also has experience as a contributing editor, and has worked as a freelance writer for a host of news and trends-related publications