Section 16 · Monograph
Onasemnogene abeparvovec (intrathecal)
Reviewed Nov 2026FDA label
ItvismaAAV9 gene therapy
- Forms
- Intrathecal: 1.2 x 10^14 vg per 3mL vial
- Dose
- One-time fixed dose 1.2 x 10^14 vg intrathecal bolus over 1-2 min (age 2+); BOXED WARNING: serious liver injury; not for patients previously treated with Zolgensma
- MOA
- Delivers a functional SMN1 gene
Black Box Warning
- Acute serious liver injury and elevated aminotransferases can occur; patients with preexisting liver impairment may be at higher risk — assess liver function before injection, administer systemic corticosteroid before and after, and monitor liver function for at least 3 months
Indications
- Treatment of spinal muscular atrophy in adult and pediatric patients 2 years of age and older with a confirmed mutation in the SMN1 geneFDA-labeled
Mechanism of Action
- Non-replicating AAV9 vector delivering a functional copy of the SMN1 gene directly to the CNS
Full Dosing
Adult / usual
- Single intrathecal bolus of 1.2 x 10^14 vg over about 1-2 minutes (fixed dose, independent of weight); each vial 1.2 x 10^14 vg in 3mL
- Postpone in patients with active infection until resolved and clinically stable
- Patients previously treated with Zolgensma should not be treated with Itvisma
Contraindications
- None listed in labeling
Drug Interactions
- Live vaccine timing during corticosteroid therapy
- Avoid additional hepatotoxic drugs
Adverse Effects
- Elevated aminotransferases and acute liver injury
- Thrombocytopenia
- Peripheral sensory neuropathy
- Thrombotic microangiopathy
- Possible increased hepatotoxicity and cardiotoxicity risk in adults with preexisting conditions
Monitoring Parameters
- Liver function before and for at least 3 months after
- Platelet counts
- Neurologic and sensory symptoms
Pregnancy & Lactation
- Limited data; not studied in pregnancy or lactation — discuss with specialist