Delandistrogene Moxeparvovec Dosage

Medically reviewed by Drugs.com. Last updated on Dec 14, 2023.

Usual Pediatric Dose for Muscular Dystrophy

Recommended Dose: A single-dose of 1.33 x 10(14) vector genomes per kilogram (vg/kg) of body weight or 10 mL/kg of body weight administered by IV infusion

• Infuse drug at a rate of less than 10 mL/kg/hour over 1 to 2 hours
• To calculate dose: Multiply patient body weight (kg) by 10 for dose of drug in milliliters
• To calculate vials needed: Divide the dose in milliliters by 10 and round to nearest number of vials

Peri-Infusion Corticosteroid Dosing Recommendations:

• If baseline steroid dose is daily or intermittent: Start 1 day prior to infusion with 1 mg/kg/day (prednisone equivalent) and continue baseline corticosteroid dose.
• If baseline steroid dose is high-dose 2 days/week: Start 1 day prior to infusion with 1 mg/kg/day (prednisone equivalent) taken on days without high-dose steroid treatment, and continue baseline corticosteroid dose.
• No corticosteroid use at baseline: Start 1 week prior to infusion with 1.5 mg/kg/day (prednisone equivalent).

Additional Corticosteroid Recommendations:

• Deflazacort not recommended for use as peri-infusion corticosteroid.
• Maximum recommended total daily steroid dose (prednisone equivalent) is 60 mg/day.
• Corticosteroids are recommended for a minimum of 60 days post-infusion.
• In patients taking corticosteroids at baseline, taper off additionally recommended steroids over 2 weeks or longer down to baseline corticosteroid dose.
• In patients who are not taking corticosteroids at baseline, taper the peri-infusion steroid dose over 4 weeks or more until patient fully tapers off corticosteroids; do not stop abruptly.

Comments:

• This drug is given as a single, one-time dose; re-administration is not recommended.
• Patients selected for therapy must have anti-AAVrh74 total binding antibody titers less than 1:400.
• Consult manufacturer product information for specific calculation recommendations and dosing examples.
• Corticosteroids are given at least one day prior to infusion to reduce risk of immune response.
• If clinical signs and symptoms of infection are present before infusion, do not administer drug.
• Assess liver function, platelet count, and troponin-I levels prior to treatment.

Use: For the treatment of ambulatory pediatric patients aged 4 through 5 years with Duchenne muscular dystrophy (DMD) with a confirmed mutation in the DMD gene.

• This indication is approved under accelerated approval based on the expression of this drug in micro-dystrophin in skeletal muscle in treated patients. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

• Acute Liver Disease: Postpone administration of this drug until resolved or controlled.
• Preexisting Liver Dysfunction or Chronic Viral Hepatitis: Consider the benefits and risks of therapy; these patients are at increased risk of liver injury.

Corticosteroid Dose Modifications in Patients with Liver Abnormalities After Infusion:

• If taking peri-infusion steroid 1 mg/kg/day (prednisone equivalent) plus baseline corticosteroids: Increase to 2 mg/kg/day (prednisone equivalent) and continue baseline corticosteroids
• If taking peri-infusion steroid 1 mg/kg/day (prednisone equivalent) on days without high-dose steroids plus baseline corticosteroids: Increase to 2 mg/kg/day (prednisone equivalent) on days without high-dose steroids and continue baseline corticosteroids
• If taking peri-infusion steroid 1.5 mg/kg/day (prednisone equivalent): Increase to 2.5 mg/kg/day (prednisone equivalent)

Additional recommendations:

• Post-infusion liver abnormalities include elevated GGT (150 U/L or greater), total bilirubin greater than 2 times the upper limit of normal, or other clinically significant abnormalities.
• Consider IV bolus corticosteroids if GGT or bilirubin elevations are unresponsive to oral doses.
• Maximum recommended total daily steroid dose (prednisone equivalent) is 120 mg/day.

Precautions

CONTRAINDICATIONS:

• In patients with any deletion in exon 8 and/or exon 9 in the DMD gene

Safety and efficacy have not been established in pediatric patients 3 years of age or younger, or in pediatric patients 6 years of age or older.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

• The manufacturer product information should be consulted prior to product administration.
• Corticosteroids should be administered prior to infusion to reduce the risk of immune response.
• Administer drug as a single-dose IV infusion through a peripheral venous catheter.
• It is recommended to insert an additional back-up catheter.
• Infuse drug at a rate of less than 10 mL/kg/hour over a duration of approximately 1 to 2 hours, or longer if clinically indicated.
• Do not administer as an IV push.

Supply and storage information:

• This drug is shipped frozen at -60 C (-76 F) or less, and supplied as a customized dosing kit.
• Store vials in the upright position under refrigeration at 2C to 8C (36F to 46F) for up to 14 days.
• Frozen vials will thaw at room temperature within 2 hours when removed from original packaging.
• Do not refreeze or place vials back in refrigerator once brought to room temperature.
• Sealed thawed vials are stable for up to 24 hours at room temperature when stored in upright position.
• Do not shake when handling.

Product preparation techniques:

• The manufacturer product information should be consulted prior to product preparation.
• Ensure required dose is based on patient body weight (kg) and that dosing kit contains sufficient vials.
• Thaw drug in refrigerator or at room temperature; ensure no ice crystals are present before use.
• Visually inspect drug products for particulate matter during preparation; drug may contain whitish particles.
• Swirl product gently; do not shake.
• Withdraw 10 mL of drug from each required vial using an appropriate syringe; do not use filter needles.
• Use drug within 4 hours of drawing it into syringe; discard any extra drug or if not used within this timeframe.

IV compatibility: Do not infuse this drug with any other product in the same IV line.

General:

• This drug is supplied as a customized dosing kit based on patient body weight; consult the manufacturer product information for multi-vial drug kit information.
• Prior to therapy, measure baseline anti-AAVrh74 antibody titers using a Total Binding Antibody enzyme-linked immunosorbent assay (ELISA).
• An FDA-authorized test for the detection of AAVrh74 total binding antibodies is not currently available; existing tests may vary in accuracy and design.
• Do not administer this drug in patients with antibody titers greater than 1:400.
• Consider the vaccination status of the patient prior to starting therapy and complete all age-appropriate immunizations at least 4 weeks before initiating the required corticosteroid pre-treatment regimen.

Monitoring:

• Assess liver function (e.g., clinical exam, GGT, and total bilirubin) weekly for the first 3 months, or longer if clinically indicated, until results are unremarkable.
• Obtain platelet counts weekly for the first two weeks, or longer if indicated.
• Measure troponin weekly for the first month, or longer if indicated.

Patient advice:

• Read the FDA-approved patient labeling (Medication Guide).
• Report symptoms of acute liver injury immediately; this drug may increase liver enzymes.
• Notify a physician if symptoms of chest pain or shortness of breath immediately.
• Ensure immunizations are up to date prior to treatment.
• Contact a physician at the onset of unexplained muscle pain or weakness, or difficulty breathing, speaking, or swallowing.
• Inform healthcare provider if symptoms suggestive of infection are observed.
• Practice proper hand hygiene after contact with patient body waste to avoid exposure during vector shedding; maintain precautions for 1 month after infusion.

Further information

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

Medical Disclaimer