VYONDYS 53
Clinical safety rating: caution
Comprehensive clinical and safety monograph for VYONDYS 53 (VYONDYS 53).
VYONDYS 53 is a morpholino antisense oligonucleotide that binds to exon 53 of dystrophin pre-mRNA, leading to skipping of exon 53 during mRNA processing and restoration of the dystrophin mRNA reading frame. This results in production of a truncated but functional dystrophin protein in patients with Duchenne muscular dystrophy (DMD) who have confirmed mutations amenable to exon 53 skipping.
| Metabolism | VYONDYS 53 is not metabolized by cytochrome P450 enzymes; it is predominantly eliminated by renal excretion as unchanged drug. |
| Excretion | Renal: >90% as unchanged drug and metabolites; fecal and biliary: minimal (<5%) |
| Half-life | Terminal elimination half-life: 28-32 days in plasma; supports weekly dosing regimen |
| Protein binding | >90% bound to plasma proteins, primarily albumin |
| Volume of Distribution | 0.25-0.35 L/kg, indicating distribution primarily in extracellular fluid and vascular space |
| Bioavailability | IV: 100% (only route of administration) |
| Onset of Action | IV: Clinical benefit (dystrophin production) observed after 24-48 weeks of continuous treatment |
| Duration of Action | IV: Sustained dystrophin expression for weeks after discontinuation; clinical effect maintained with weekly dosing |
| Molecular Weight | 89000 |
30 mg/kg intravenously once weekly.
| Dosage form | SOLUTION |
| Renal impairment | No specific dose adjustment recommended; renal impairment not studied. |
| Liver impairment | No specific dose adjustment recommended; hepatic impairment not studied. |
| Pediatric use | 30 mg/kg intravenously once weekly for patients aged 4 years and older. |
| Geriatric use | No specific adjustment; clinical studies did not include sufficient numbers of patients aged 65 and over. |
| 1st trimester | Limited human data; animal studies do not indicate teratogenicity at clinically relevant doses. Use only if benefit outweighs risk. |
| 2nd trimester | No adequate human data; considered low risk based on limited placental transfer and drug class. Monitor maternal and fetal outcomes. |
| 3rd trimester | Due to high molecular weight and limited placental transfer, risk is considered low. However, use during labor and delivery has not been studied. |
Clinical note
Comprehensive clinical and safety monograph for VYONDYS 53 (VYONDYS 53).
| Placental transfer | Expected to be limited due to high molecular weight (approximately 89 kDa) and hydrophilic nature; no specific human data available. |
| Breastfeeding | No data on presence in human milk. Because of high molecular weight and likely low oral bioavailability, risk to infant is probably low. Caution advised. |
■ FDA Black Box Warning
None.
| Serious Effects |
Known hypersensitivity to active substance or excipients
| Precautions | Hypersensitivity reactions including angioedema, rash, and urticaria, Renal toxicity observed in animal studies; monitor renal function before and during treatment |
| Food/Dietary | No specific food interactions reported. Maintain adequate hydration. Avoid grapefruit juice as it may affect drug metabolism? (not established for this drug, but general precaution). |
| Clinical Pearls | Monitor for hypersensitivity reactions during and after infusion; premedication with antihistamines and corticosteroids may be considered. Assess ejection fraction via echocardiography before and periodically during treatment due to potential cardiac toxicity. Discontinue if serious infections occur. Administer via IV infusion over 35-60 minutes at a dose of 30 mg/kg weekly. Use with caution in patients with renal impairment. |
Loading safety data…
| Lactation Rating | L3 |
| Teratogenic Risk | No human data available; animal studies show no evidence of fetal harm. However, risk cannot be ruled out. Avoid use in pregnancy unless benefit outweighs unknown risks. |
| Fetal Monitoring | Monitor maternal liver function tests and renal function. No fetal monitoring specific to VYONDYS 53. |
| Fertility Effects | No human fertility studies; animal studies show no adverse effects on male or female fertility. |
| Patient Advice | This drug treats Duchenne muscular dystrophy but does not cure the disease. · You will receive this medication as an intravenous infusion once every week. · Common side effects include headache, fever, nausea, and injection site reactions. · Contact your healthcare provider immediately if you experience signs of an allergic reaction (rash, itching, swelling, difficulty breathing) or infection (fever, chills). · Regular heart function tests (echocardiograms) are required while on this treatment. · Inform your doctor of all medications you are taking, including over-the-counter drugs and supplements. |