Zolgensma (onasemnogene abeparvovec)
An approved treatment for Spinal Muscular Atrophy.
The same compound appears under different names depending on the context. Here is how to identify Onasemnogene abeparvovec wherever you encounter it, plus the key facts at a glance.
- Generic name
- Onasemnogene abeparvovec
- Brand name
- Zolgensma
- Development code
- AVXS-101
- Drug class
- Gene therapy
- Manufacturer
- Novartis Gene Therapies
- How it's taken
- Given as a single one-time intravenous infusion over approximately 60 minutes.
A one-time gene therapy for SMA that delivers a working copy of the SMN1 gene. Given as a single IV infusion, Zolgensma was the most expensive drug in the world at launch ($2.1 million) and has dramatically changed outcomes for infants with SMA.
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Where Onasemnogene abeparvovec fits
One-time IV gene therapy for SMA, primarily used in infants and young children. Curative-intent treatment delivering a working copy of the SMN1 gene, eliminating the need for ongoing therapy.
How Onasemnogene abeparvovec works
Zolgensma uses a harmless virus (AAV9) that can cross from the bloodstream into the central nervous system. The virus carries a working copy of the SMN1 gene. Once delivered to motor neurons, the cells begin producing their own SMN protein permanently. The delivered gene mostly stays separate from the cell's own DNA, and because motor neurons do not divide, a single dose can provide lasting benefit.
Mechanism: AAV9-based gene therapy that delivers a functional copy of the SMN1 gene to motor neurons
Side effects and safety
Zolgensma has a boxed warning for serious liver injury and acute liver failure, including deaths, so liver function is checked before the infusion and for at least 3 months after. The most common side effects are elevated liver enzymes and vomiting. Low platelet counts, thrombotic microangiopathy (TMA, a dangerous clotting problem that can harm the kidneys) and raised troponin (a heart marker) can also occur. Patients receive corticosteroids before and after infusion to manage immune response. The label also warns about infusion reactions, a body-wide immune response (so the child should be in stable health and free of infection before the infusion), and a theoretical risk of tumors from the gene therapy.
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Onasemnogene abeparvovec
Given as a single one-time intravenous infusion over approximately 60 minutes. Approved for children under 2 years old (IV formulation). Requires pre-treatment liver function screening and ongoing monitoring. Corticosteroid course is given before and tapered after.
Availability and cost
Only available as the brand-name product.
One-time AAV9 gene therapy delivering a functional SMN1 gene. Among the most expensive single-administration therapies, reflecting curative intent and complex viral vector manufacturing.
Help paying for Zolgensma
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Insurance and case manager help
A dedicated Case Coordinator helps with benefits verification, prior authorization, appeals, finding financial support, and tracking the treatment to the infusion site.
The official page does not say who qualifies. Ask the program. · source - Copay help
ZOLGENSMA CopayAssist Program helps eligible, commercially insured US residents with out-of-pocket costs.
For: private insurance · source - Free medicine program
A Novartis Patient Assistance Program for ZOLGENSMA is available for qualified patients and families; contact Novartis Patient Support for details.
The official page does not say who qualifies. Ask the program. · source
Good to know: Eligibility rules for the patient assistance program and the CopayAssist dollar limits are not stated on the official page; call Novartis Patient Support (Mon-Fri 8 AM-8 PM ET).
- From a charity · TotalAssist (formerly PAN Foundation)Spinal Muscular Atrophy fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $6,500 per year. Requires health insurance (any kind).
- From a charity · Cure SMAEquipment Pool and Travel Support Package fundApply directly
Pays for: Medical equipment loans (wheelchairs, car beds) and travel equipment.
The foundation says: “Status not shown on page” - From a charity · Muscular Dystrophy AssociationMDA Durable Medical Equipment (DME) Grant Program fundApply directly
Pays for: Medical equipment (wheelchairs, lifts, canes and other DME), up to $1,000 per year.
The foundation says: “Status not shown on page”
Clinical trial results
The STR1VE trial showed 91% of treated infants were alive and ventilator-free at 14 months, versus historical survival of about 25%. Many infants achieved sitting, standing, and walking milestones never seen in untreated SMA Type 1.
Development history
Originally developed by AveXis (acquired by Novartis for $8.7 billion in 2018). Approved May 2019. Made headlines as the world's most expensive drug at $2.1 million. An intrathecal formulation (Itvisma) for older patients was approved in late 2025.
Explore Spinal Muscular Atrophy trials
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Onasemnogene abeparvovec in Trial Friend News and Guides
Common questions about Onasemnogene abeparvovec
▸What is Onasemnogene abeparvovec (Zolgensma)?
A one-time gene therapy for SMA that delivers a working copy of the SMN1 gene. Given as a single IV infusion, Zolgensma was the most expensive drug in the world at launch ($2.1 million) and has dramatically changed outcomes for infants with SMA.
▸How does Onasemnogene abeparvovec work?
Zolgensma uses a harmless virus (AAV9) that can cross from the bloodstream into the central nervous system. The virus carries a working copy of the SMN1 gene. Once delivered to motor neurons, the cells begin producing their own SMN protein permanently. The delivered gene mostly stays separate from the cell's own DNA, and because motor neurons do not divide, a single dose can provide lasting benefit.
▸What are the side effects of Onasemnogene abeparvovec?
Zolgensma has a boxed warning for serious liver injury and acute liver failure, including deaths, so liver function is checked before the infusion and for at least 3 months after. The most common side effects are elevated liver enzymes and vomiting. Low platelet counts, thrombotic microangiopathy (TMA, a dangerous clotting problem that can harm the kidneys) and raised troponin (a heart marker) can also occur. Patients receive corticosteroids before and after infusion to manage immune response. The label also warns about infusion reactions, a body-wide immune response (so the child should be in stable health and free of infection before the infusion), and a theoretical risk of tumors from the gene therapy.
▸How is Onasemnogene abeparvovec taken?
Given as a single one-time intravenous infusion over approximately 60 minutes. Approved for children under 2 years old (IV formulation). Requires pre-treatment liver function screening and ongoing monitoring. Corticosteroid course is given before and tapered after.
▸Is Onasemnogene abeparvovec FDA approved?
Yes, Onasemnogene abeparvovec (Zolgensma) is FDA approved (2019) for the treatment of Spinal Muscular Atrophy.
▸What makes Zolgensma a gene therapy?
Zolgensma uses an AAV9 viral vector to deliver a functional copy of the SMN1 gene to motor neurons. After a single IV infusion, the patient's cells can produce SMN protein on their own, addressing the root genetic cause of SMA.
▸Who is eligible for Zolgensma IV?
Zolgensma IV infusion is approved for children under 2 years of age with SMA caused by mutations in both copies of the SMN1 gene. It has not been studied in children with advanced SMA, such as complete paralysis of the limbs or permanent ventilator dependence. Patients are screened for AAV9 antibodies before treatment, as pre-existing antibodies can prevent successful gene delivery.
▸Is Zolgensma a one-time treatment?
Yes. Zolgensma is given as a single one-time intravenous infusion, in contrast to nusinersen (ongoing intrathecal injections) and risdiplam (daily oral medication). The goal is sustained SMN protein production from the delivered gene.
▸What monitoring is needed after Zolgensma?
Close liver function monitoring is required for at least 3 months after infusion, as liver enzyme elevations are common. Corticosteroids are given to manage the immune response to the viral vector. Platelet counts and troponin levels are also monitored.
▸How does Zolgensma IV compare to the intrathecal version?
Zolgensma IV is for children under 2, while the intrathecal version (onasemnogene-abeparvovec-brve) was approved in 2025 for patients aged 2 and older. The IV version delivers the gene throughout the body, while the intrathecal version delivers directly to the spinal fluid.
▸What patient support does Novartis offer?
Novartis Gene Therapies provides comprehensive support for Zolgensma patients including insurance navigation, copay assistance, and treatment center coordination through dedicated case managers.