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Onasemnogene Abeparvovec Dosage

Medically reviewed by Drugs.com. Last updated on March 13, 2020.

Applies to the following strengths: 20 trillion vg/mL

Usual Pediatric Dose for Spinal Muscular Atrophy

Prior to infusion:
-Assess liver function
-Obtain platelet counts and troponin-I
-Assess for the presence of anti-AAV9 antibodies

Corticosteroid
-Initiate systemic corticosteroids (equivalent to oral prednisolone 1 mg/kg/day) 1 day prior to IV infusion and continue for a total of 30 days

Single-dose IV infusion: 1.1 x 10(14) vector genomes/kg IV infusion over 60 minutes

Comments:
-See other comments/administration advice for guidance on administration; a dose table that provides dose volume (mL) based on weight may be found in manufacturer's product labeling.
-The use in patients with advance spinal muscular atrophy (e.g., complete paralysis of limbs, permanent ventilator-dependence) has not been evaluated.
-The safety and effectiveness of repeat administration have not been evaluated.

Use: For the treatment of patients less than 2 years of age with spinal muscular atrophy with bi-allelic mutations in the survival motor neuron 1 gene.

Renal Dose Adjustments

No adjustment recommended

Liver Dose Adjustments

Use with caution; patients with preexisting liver impairment may be at higher risk for liver injury

Routine liver function monitoring should be performed in all patients

Precautions

US BOXED WARNING: ACUTE SERIOUS LIVER INJURY
-Acute serious liver injury and elevated aminotransferases can occur with this drug; patients with preexisting liver impairment may be at higher risk.
-Prior to infusion, assess liver function by clinical examination and laboratory testing (e.g., hepatic transaminases [ALT, AST], total bilirubin, and prothrombin time).
-Administer systemic corticosteroid before and after infusion; continue to monitor liver function for at least 3 months after infusion.

CONTRAINDICATIONS:
-None

Safety and efficacy have not been established in premature neonates before reaching full-term gestational age and is not recommended because concomitant treatment with corticosteroids may adversely affect neurological development

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:
-Administer as a slow IV infusion over 60 minutes; do not infuse as an IV push or bolus

Prior to Infusion:
-Place a primary catheter into vein (generally a peripheral vein in the arm or leg); insertion of a back-up catheter is recommended
-Program syringe pump for saline priming, or prime tubing manually with saline

Following Infusion:
-Flush line with saline

Storage requirements:
-Shipped frozen (-76F [-60C]); Upon receipt, immediately refrigerate 36F to 46F (2C to 8C)
-Stable for 14 days from receipt when stored refrigerated; Do not refreeze; must use within 14 days of receipt
-Once drawn up in syringe for administration, keep at room temperature and use within 8 hours

Reconstitution/preparation techniques:
-Thaw before use; will thaw in approximately 12 hours in the refrigerator or 4 hours at room temperature
-Once thawed, suspension should be clear to slightly opaque (colorless to faint white); do not use if particulates or discoloration are present
-Do not shake
-Draw appropriate dose volume into syringe and deliver syringe at room temperature to infusion location; use within 8 hours; discard if not used within 8-hour timeframe

General:
-Alterations in vaccination schedule may be necessary during corticosteroid use; prophylaxis against respiratory syncytial virus is recommended.

Monitoring:
Prior to Infusion:
-Assess liver function (clinical exam, AST, ALT, total bilirubin, prothrombin time)
-Obtain troponin-I levels and perform baseline testing for the presence of anti-AAV9 antibodies; may retest if anti-AAV9 antibody titers are greater than 1:50
Following Infusion:
-Liver: Clinical exam, AST, ALT, total bilirubin, and prothrombin time weekly for first month and every other week for the second and third month until results are unremarkable (normal clinical exam, total bilirubin, prothrombin time, and ALT and AST levels below 2 x upper limit of normal)
-Troponin-I weekly for first month, then monthly for second and third months until levels return to normal

Patient advice:
-Caregivers should be instructed to report any signs of liver injury such as skin or whites of eyes appearing yellow; any unexpected bruising or bleeding should be reported.
-Caregivers should be instructed to report missed corticosteroid doses.
-Caregivers should contact their healthcare provider if patient develops signs of a viral respiratory infection.
-Caregivers should be aware that vector shedding may occur primarily through body waste; precautions should be followed for 1 month following infusion and include: sealing disposable diapers in disposable trash bags and discarding into regular trash; proper hand hygiene when coming into direct contact with patient body waste.

Frequently asked questions

Further information

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