Onasemnogene Abeparvovec-Xioi
Onasemnogene abeparvovec-xioi (Zolgensma) is a one-time gene therapy used to treat spinal muscular atrophy (SMA) in children under 2 years old who have a specific genetic mutation causing the disease.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Zolgensma is a landmark one-time gene therapy for children under 2 with spinal muscular atrophy (SMA) caused by SMN1 gene mutations, using a non-replicating virus to deliver a working gene so motor neurons (the nerves that control movement) can make a protein they need to survive, and it has been on the market since about 2019. Vomiting and fever are the side effects families notice most, and blood tests commonly show raised liver enzymes and a temporary dip in platelets (clotting cells). Its boxed warning is serious liver injury and acute liver failure, including fatal cases, which is why steroids start the day before the infusion and liver tests continue for at least 3 months.
Clinical pearls
- The steroid course lasts at least 30 days and is tapered gradually, and it must never be stopped abruptly.
- Between lab checks, yellowing skin or eyes, vomiting or your child seeming unwell means calling the care team right away.
- Report unusual bruising, seizures or reduced urine in the first two weeks, signs of a rare, dangerous blood and kidney problem.
- Live vaccines like MMR and chickenpox wait until high-dose steroids end, while flu and RSV protection is recommended around the infusion.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Zolgensma carries a serious warning about liver injury, including cases of acute liver failure that have resulted in death. Elevated liver enzymes and acute liver damage can occur after the infusion. Children who already have liver problems are at even greater risk. Before the infusion, all patients must have their liver function checked. A steroid medication must be given starting the day before the infusion and continued afterward. Liver function must continue to be monitored for at least 3 months after the infusion. Watch for warning signs such as vomiting, yellowing of the skin or eyes, or a noticeable decline in your child's health, and contact your care team right away if these occur.
Patient information guide A plain-language walkthrough of Onasemnogene Abeparvovec-Xioi, written from its FDA label.
What Onasemnogene Abeparvovec-Xioi is used for
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Zolgensma (onasemnogene abeparvovec-xioi) is a gene therapy approved for one specific condition:
- Spinal muscular atrophy (SMA) in pediatric patients less than 2 years of age who have bi-allelic mutations in the SMN1 gene — meaning both copies of the gene are defective or missing
- Zolgensma has not been evaluated for patients with advanced SMA (such as complete limb paralysis or permanent ventilator dependence), and its safety and effectiveness for repeat administration have not been established
How Onasemnogene Abeparvovec-Xioi works
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SMA is caused by mutations in the SMN1 gene that leave the body unable to produce enough SMN (survival motor neuron) protein — a protein that motor neurons, the nerve cells controlling muscle movement, need to function and survive. Zolgensma uses an engineered, non-replicating viral carrier (an AAV9 vector) to deliver a working copy of the SMN1 gene directly into cells via a single IV infusion. Once inside the cells, the new gene instructs them to produce SMN protein, supporting motor neuron health and function. Evidence from human cases shows that cell uptake and SMN protein production occur in spinal motor neurons, brain cells, heart, liver, and skeletal muscle after infusion.
Onasemnogene Abeparvovec-Xioi dosage
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Zolgensma is given as a single, one-time intravenous (IV) infusion over approximately 60 minutes through a vein — always administered by a healthcare team in a clinical setting, never at home. The dose is calculated based on the child's body weight. It cannot be repeated, as the safety and effectiveness of a second dose have not been evaluated.
- A steroid medication (equivalent to oral prednisolone) is started the day before the infusion and continued daily for 30 days, then gradually tapered — it must never be stopped abruptly
- If the child has an active infection, the infusion must be postponed until they have fully recovered
- Liver function, platelet counts, and other lab tests are monitored before and for at least 3 months after the infusion
Dosing details from the FDA-approved label
From the Onasemnogene Abeparvovec-Xioi prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Recommended dosage (single-dose intravenous infusion only)
- 1.1 × 10 14 vector genomes (vg) per kg of body weight, administered as an intravenous infusion over 60 minutes (slow infusion through a venous catheter
- Do not infuse as an intravenous push or bolus)
- Dose volume ranges from 16.5 mL for 2.6 – 3.0 kg to 115.5 mL for 20.6 – 21.0 kg
- Dose volume is calculated using the upper limit of the patient weight range for pediatric patients less than 2 years of age between 2.6 kg and 21.0 kg
- Systemic corticosteroids with ZOLGENSMA (starting one day prior to infusion)
- Systemic corticosteroids equivalent to oral prednisolone at 1 mg/kg of body weight per day for a total of 30 days
- At the end of the 30 days, if findings are unremarkable, taper gradually over the next 28 days
- If liver function abnormalities persist, continue 1 mg/kg/day until AST and ALT are both below 2 × ULN and all other assessments return to normal ran
- If abnormalities persist ≥ 2 × ULN after 30 days, promptly consult a pediatric gastroenterologist or hepatologist; if oral therapy is not tolerated, consider intravenous corticosteroids
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION For single-dose intravenous infusion only. For single-dose intravenous infusion only ( 2 ). The recommended dosage of ZOLGENSMA is 1.1 × 10 14 vector genomes (vg) per kg of body weight. ( 2.1 ) Administer ZOLGENSMA as an intravenous infusion over 60 minutes. ( 2.1 , 2.3 ) Postpone ZOLGENSMA in patients with infections until the infection has resolved and the patient is clinically stable. ( 2.1 , 5.2 ) Starting one day prior to ZOLGENSMA infusion, administer systemic corticosteroids equivalent to oral prednisolone at 1 mg/kg of body weight per day for a total of 30 days. At the end of the 30-day period, check liver function by clinical examination and by laboratory testing. For patients with unremarkable findings, taper the corticosteroid dose gradually over the next 28 days. If liver function abnormalities persist, continue systemic corticosteroids (equivalent to oral prednisolone at 1 mg/kg/day) until findings become unremarkable, and then taper the corticosteroid dose gradually over the next 28 days or longer if needed. Do not stop systemic corticosteroids abruptly. ( 2.1 ) If liver function abnormalities continue to persist ≥ 2 × ULN after the 30-day period of systemic corticosteroids, promptly consult a pediatric gastroenterologist or hepatologist. ( 2.1 ) 2.1 Dose and Administration The recommended dose of ZOLGENSMA is 1.1 × 10 14 vector genomes per kilogram (vg/kg) of body weight. Table 1: Dosing Patient weight range (kg) Dose volume a (mL) a Dose volume is calculated using the upper limit of the patient weight range for pediatric patients less than 2 years of age between 2.6 kg and 21.0 kg.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Onasemnogene Abeparvovec-Xioi side effects
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The most commonly reported side effects after Zolgensma infusion include:
Common side effects
- Elevated liver enzymes (aminotransferases)
- Vomiting
- Temporary drop in platelet count (thrombocytopenia)
- Fever
- Infusion-related reactions (such as rash or changes in heart rate or blood pressure)
- Elevated cardiac troponin I (a marker of heart stress)
When to get medical help
- Call your doctor immediately if your child shows signs of liver trouble: yellowing of the skin or eyes (jaundice), vomiting, or a general decline in health
- Seek emergency care for signs of a serious immune reaction: high fever, severe low blood pressure, or difficulty breathing during or after the infusion
- Watch for signs of thrombotic microangiopathy (TMA): high blood pressure, unusual bruising, seizures, or reduced urine output — especially in the first two weeks
- Report any signs of anaphylaxis (severe allergic reaction): hives, difficulty breathing, swelling, or collapse
- Tell your care team right away if any tumor or unusual growth develops after treatment
- Tell your care team if your child develops any infection before or after the infusion
Serious reactions — including acute liver failure, severe immune responses, thrombotic microangiopathy (TMA), and anaphylaxis — have been reported and require immediate medical attention.
Onasemnogene Abeparvovec-Xioi warnings and precautions
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- Serious liver injury and acute liver failure (including fatal cases): All patients need liver testing before the infusion and weekly monitoring for at least the first month, then ongoing for at least 3 months. Steroids are mandatory before and after infusion to reduce this risk. Pre-existing liver disease increases the danger significantly.
- Systemic immune response: The infusion activates the immune system. If a child has any active infection, infusion must be delayed. High fever, low blood pressure, or rapid clinical decline can signal a serious immune reaction.
- Thrombocytopenia (low platelet counts): Platelet counts can drop — sometimes sharply — especially in the first two weeks. Regular blood counts are required.
- Thrombotic microangiopathy (TMA): A rare but life-threatening condition affecting blood, kidneys, and other organs that can occur within the first two weeks. Signs include high blood pressure, unusual bruising, seizures, or reduced urine output.
- Elevated heart troponin I: Increases in this heart marker have been seen after infusion; cardiac evaluation may be needed.
- Theoretical risk of tumorigenicity: Because the viral vector DNA can integrate into the genome (DNA), there is a theoretical long-term risk of tumor development. Cases of tumors have been reported post-approval, though a direct causal link has not been confirmed. Any new tumor should be reported to Novartis Gene Therapies.
- Infusion-related reactions: Including anaphylaxis. Medical staff monitor the child during and after the infusion and are prepared to respond.
Onasemnogene Abeparvovec-Xioi interactions
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Zolgensma interacts primarily with vaccines and infection-related considerations due to the required corticosteroid (steroid) treatment and immune activation from the infusion:
- Live vaccines (e.g., MMR, varicella/chickenpox): These are contraindicated (not safe to give) while a child is on high-dose steroids, which are required around the time of Zolgensma infusion — vaccination schedules must be adjusted in advance
- Seasonal flu vaccine and RSV prophylaxis: Recommended before and after Zolgensma infusion to reduce infection risk during a period of immune activation
- Active infections: Any concurrent infection can worsen the immune response to Zolgensma, increasing the risk of serious outcomes — infusion must be postponed until the child is infection-free
Interactions listed in the FDA-approved label
From the Onasemnogene Abeparvovec-Xioi prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Vaccines (general): Concomitant corticosteroid administration prior to and following ZOLGENSMA infusion may affect the patient's vaccination schedule. Where feasible, adjust the patient's vaccination schedule to accommodate concomitant corticosteroid administration prior to and following ZOLGENSMA infusion.
- Live vaccines such as measles, mumps, and rubella (MMR) and varicella: Contraindicated for patients on a substantially immunosuppressive steroid dose (i.e., ≥ 2 weeks of daily receipt of 20 mg or 2 mg/kg body weight of prednisone or equivalent).
Read the label’s full interactions text
7 DRUG INTERACTIONS Where feasible, adjust a patient’s vaccination schedule to accommodate concomitant corticosteroid administration prior to and following ZOLGENSMA infusion [see Dosage and Administration ( 2.1 )] . Certain vaccines, such as measles, mumps, and rubella (MMR) and varicella, are contraindicated for patients on a substantially immunosuppressive steroid dose (i.e., ≥ 2 weeks of daily receipt of 20 mg or 2 mg/kg body weight of prednisone or equivalent). Seasonal RSV prophylaxis is recommended (General Best Practice Guidelines for Immunization [ www.cdc.gov/vaccines/hcp/acip-recs/general-recs/downloads/general-recs.pdf ], eds2017). Where feasible, adjust a patient’s vaccination schedule to accommodate concomitant corticosteroid administration prior to and following ZOLGENSMA infusion. ( 7 )
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Onasemnogene Abeparvovec-Xioi
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- Pre-existing liver disease: Patients with liver impairment are at higher risk of serious liver injury or acute liver failure — risks and benefits must be carefully weighed
- Anti-AAV9 antibody levels: Must be tested before infusion; patients with antibody titers above 1:50 have not been evaluated for safety or effectiveness
- Premature infants: Zolgensma should be delayed until the child reaches full-term gestational age, because the required steroids can harm neurological development in premature babies
- Active infection: Infusion must be postponed until any infection has fully resolved and the child is clinically stable
- Vaccination status: Should be up to date before treatment, with scheduling adjusted around the steroid regimen
- Platelet counts and kidney function: Baseline blood tests including platelet count and creatinine are required before infusion
- Pregnancy: No data exist on Zolgensma use in pregnant women; animal studies showed no fetal risk, but this is a therapy designed for young children
- Repeat dosing: The safety of a second infusion has not been evaluated and is not recommended
How your body processes Onasemnogene Abeparvovec-Xioi
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After Zolgensma is infused, the viral vector (the carrier delivering the gene) is shed in saliva, urine, and stool — with the highest concentrations found in stool. Vector DNA in saliva becomes undetectable within about 3 weeks; in urine, within 1–2 weeks; and in stool, within 1–2 months after infusion. Inside the body, the highest concentrations of vector DNA are found in the liver, but the gene also reaches the spleen, heart, skeletal muscles, spinal cord, brain, and many other tissues. SMN protein — the protein the therapy is designed to produce — has been detected in spinal motor neurons, brain cells, heart, liver, and skeletal muscle following infusion.
How to store Onasemnogene Abeparvovec-Xioi
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Product is shipped and delivered frozen (≤ -60°C ) in clear vials. refrigerator at 2°C to 8°C (36°F to 46°F). stored at 2°C to 8°C (36°F to 46°F).
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Onasemnogene Abeparvovec-Xioi: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Onasemnogene Abeparvovec-Xioi — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly does Zolgensma do for my child?
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Is this really a one-time treatment? Will my child ever need it again?
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What is the biggest risk I should know about?
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Why does my child need steroids before and after the infusion?
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What side effects should I watch for at home after the infusion?
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Can my child get their vaccines on their normal schedule around the time of Zolgensma?
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Is Onasemnogene Abeparvovec-Xioi available over the counter?
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When was Onasemnogene Abeparvovec-Xioi first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Onasemnogene Abeparvovec-Xioi on HelloPharmacist
Onasemnogene Abeparvovec-Xioi on the U.S. market: products, makers and brands
How Onasemnogene Abeparvovec-Xioi appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 37 Onasemnogene Abeparvovec-Xioi product records with the FDA; the earliest marketing or approval year on record is 2019. Brand names on the directory include Zolgensma, Itvisma; the rest are generics.
Also listed with the FDA, not a patient dose form: Kit (133) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Compare Onasemnogene Abeparvovec-Xioi products
A representative set of FDA-listed product records for Onasemnogene Abeparvovec-Xioi — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|
| 💊Kits | ||
| Novartis Innovative Technologies Inc. × 37 listings | BLA | View NDC → |
Showing 37 of 37 products — FDA National Drug Code Directory. See every product, package size and price: browse all 37 Onasemnogene Abeparvovec-Xioi NDCs →
Onasemnogene Abeparvovec-Xioi side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Onasemnogene Abeparvovec-Xioi — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Onasemnogene Abeparvovec-Xioi in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Onasemnogene Abeparvovec-Xioi FDA approval history
How Onasemnogene Abeparvovec-Xioi went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Onasemnogene Abeparvovec-Xioi recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Onasemnogene Abeparvovec-Xioi recalls since July 2021.
✅No Onasemnogene Abeparvovec-Xioi recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2170226 1 dose form · 3 strengths
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Dose form (SCDF) Injection RxCUI 2170229No current FDA listingClinical drug / strength (SCD) 3 ML onasemnogene abeparvovec-brve 40000000000000 VECTOR-GENOMES/MLRxCUI 27273075.5 ML onasemnogene abeparvovec-xioi 20000000000000 VECTOR-GENOMES/MLRxCUI 21702398.3 ML onasemnogene abeparvovec-xioi 20000000000000 VECTOR-GENOMES/MLRxCUI 2170244
Look up RxCUI 2170226 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Onasemnogene Abeparvovec-Xioi supply and shortage status
Whether Onasemnogene Abeparvovec-Xioi is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Onasemnogene Abeparvovec-Xioi brand names
Onasemnogene Abeparvovec-Xioi is sold under 2 brand names in the FDA directory — Zolgensma, Itvisma. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Onasemnogene Abeparvovec-Xioi: manufacturers and labelers
One company lists Onasemnogene Abeparvovec-Xioi products with the FDA. By number of product records, the largest are Novartis Innovative Technologies Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Onasemnogene Abeparvovec-Xioi drug class (RxNorm)
Onasemnogene Abeparvovec-Xioi belongs to the Other drugs for disorders of the musculo-skeletal system class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Onasemnogene Abeparvovec-Xioi page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Novartis Gene Therapies, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →