Skip to main content

Onasemnogene Abeparvovec

Medically reviewed by Last updated on Feb 23, 2023.


(ON a SEM noe jeen A be PAR voe vek)

Index Terms

  • Onasemnogene abeparvovec-xioi
  • Zolgensma

Dosage Forms

Suspension, Injection [preservative free]

Zolgensma: onasemnogene abeparvovec-xioi 20000000000000 VG/mL (5.5 mL, 8.3 mL)

Brand Names: U.S.

  • Zolgensma

Pharmacologic Category

  • Gene Therapy, Adeno-Associated Virus


A recombinant adeno-associated virus vector-based gene therapy that delivers a normal copy of the gene encoding human survival motor neuron (SMN) protein.

Use: Labeled Indications

Spinal muscular atrophy: Treatment of pediatric patients <2 years of age with spinal muscular atrophy (SMA) with bi-allelic mutations in the survival motor neuron 1 (SMN1) gene

Limitations of use: Safety and effectiveness of repeat administration has not been evaluated. Use in patients with advanced SMA (eg, complete paralysis of limbs, permanent ventilator-dependence) has not been evaluated.


There are no contraindications listed in the manufacturer's labeling.

Dosing: Pediatric

Spinal muscular atrophy (SMA): Note: One day prior to infusion, administer oral corticosteroids (eg prednisolone 1 mg/kg/dose once daily or equivalent) and continue for at least 30 days.

Infants and Children <2 years: IV infusion: 1.1 x 1014 vector genomes/kg as a single dose.

Dose volume based on weight range:

Weight range (kg)

Dose Volume (mL)

2.6 to 3


3.1 to 3.5


3.6 to 4


4.1 to 4.5


4.6 to 5


5.1 to 5.5


5.6 to 6


6.1 to 6.5


6.6 to 7


7.1 to 7.5


7.6 to 8


8.1 to 8.5


8.6 to 9


9.1 to 9.5


9.6 to 10


10.1 to 10.5


10.6 to 11


11.1 to 11.5


11.6 to 12


12.1 to 12.5


12.6 to 13


13.1 to 13.5



Multiple kits will be required.

Concomitant therapy: Beginning the day prior to onasemnogene abeparvovec infusion, oral prednisolone (1 mg/kg/day or equivalent) should be administered and continued for ≥30 days to help prevent hepatic toxicity. At the end of 30 days, clinically assess liver and test hepatic function (ALT, AST, total bilirubin, and prothrombin time [PT]); if unremarkable findings (normal clinical exam, total bilirubin, and PT, and ALT and AST concentrations <2 x ULN), taper prednisolone over 28 days. If evidence of hepatic impairment exists, continue oral prednisolone (1 mg/kg/day or equivalent) until AST/ALT <2 x ULN and all other assessments return to normal, then taper over 28 days. If unresponsive to corticosteroid therapy, consult expert.


Product is shipped and delivered frozen at ≤-60°C (-76°F). Upon receipt, store at 2°C to 8°C (36°F to 46°F) for ≤14 days. Do not refreeze.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.


Hepatic: Increased serum alanine aminotransferase (≤27%), increased serum aspartate aminotransferase (≤27%)

Immunologic: Antibody development (100%)

1% to 10%: Gastrointestinal: Vomiting (7%)

Frequency not defined:

Hematologic & oncologic: Thrombocytopenia

Miscellaneous: Troponin increased in blood specimen

<1%, postmarketing, and/or case reports: Acute hepatotoxicity, jaundice

ALERT: U.S. Boxed Warning

Acute serious liver injury

Acute serious liver injury and elevated aminotransferases can occur with onasemnogene abeparvovec. Patients with preexisting liver impairment may be at higher risk. Prior to infusion, assess liver function of all patients by clinical examination and laboratory testing (eg, hepatic aminotransferases [aspartate aminotransferase (AST) and alanine aminotransferase (ALT)], total bilirubin, and prothrombin time). Administer systemic corticosteroid to all patients before and after onasemnogene abeparvovec infusion. Continue to monitor liver function for at least 3 months after infusion.


Concerns related to adverse effects:

• Cardiac effects: Transient increases in troponin-I levels have been observed, but clinical significance is unknown; cardiac toxicity was observed in animal studies. Monitor troponin-I prior to initiation of therapy and for ≥3 months after infusion.

• Hepatic effects: [US Boxed Warning]: Acute serious liver injury and elevated serum liver aminotransferases can occur. Use with caution in patients with preexisting liver impairment. Monitor liver function prior to initiation of therapy and for ≥3 months after infusion. Administer a corticosteroid to all patients before and after infusion.

• Thrombocytopenia: Transient decreases in platelet counts have been observed; monitor platelet counts before and after therapy.

Concurrent drug therapy issues:

• Vaccines: Vaccination schedule may need adjusted due to corticosteroid administration before and after onasemnogene abeparvovec infusion.

Other warnings/precautions:

• Immunogenicity: Safety and efficacy has not been evaluated in patients with anti-AAV9 antibody titers above 1:50. Perform baseline testing for the presence of anti-AAV9 antibodies; retesting may be performed if anti-AAV9 antibody titers are reported as >1:50.

• Vector shedding: Temporary vector shedding of onasemnogene abeparvovec occurs primarily through body waste. Recommended procedures when handling patient feces include sealing disposable diapers in disposable trash bags and then discarding into regular trash. Use proper hand hygiene when coming into direct contact with patient body waste. Follow these precautions for one month after the infusion.

Monitoring Parameters

Anti-AAV9 antibody testing at baseline (may re-test if anti-AAV9 antibody titers are reported >1:50)

Liver function: Clinical exam, AST, ALT, total bilirubin, prothrombin time at baseline, weekly for the first month, then every other week for the second and third months; continue testing until results are unremarkable (normal clinical exam, total bilirubin and prothrombin time; AST and ALT levels <2 x ULN).

Platelet count: Baseline, weekly for the first month, then every other week for the second and third months; continue testing until platelet count returns to baseline

Troponin-I: Baseline, weekly for the first month, then monthly for the second and third months; continue testing until troponin-I level returns to baseline

Pregnancy Considerations

Animal reproduction studies have not been conducted. Onasemnogene abeparvovec is not approved for use in patients of reproductive age.

Frequently asked questions

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.