NEXVIAZYME
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NEXVIAZYME (NEXVIAZYME).
Avalglucosidase alfa is a recombinant human acid alpha-glucosidase (GAA) that replaces deficient GAA, cleaving lysosomal glycogen and reducing accumulation.
| Metabolism | Degraded via proteolysis into small peptides and amino acids. |
| Excretion | Primarily cleared via receptor-mediated endocytosis followed by lysosomal degradation; minimal renal excretion (<3% unchanged in urine). |
| Half-life | 30.7 hours (range 23.8-38.7) in patients with infantile-onset Pompe disease; supports every 2-week dosing. |
| Protein binding | ~49% bound to plasma proteins (predominantly alpha-2-macroglobulin). |
| Volume of Distribution | 0.87 L/kg (approximates extracellular fluid volume, consistent with limited tissue distribution). |
| Bioavailability | Not applicable; administered intravenously; absolute bioavailability is 100%. |
| Onset of Action | Not applicable; enzyme replacement therapy; clinical improvement observed after 3-6 months of regular intravenous infusions. |
| Duration of Action | Sustained glycogen reduction in tissues over 2-week dosing interval; continuous treatment required to maintain effect. |
Intravenous infusion of 20 mg/kg of actual body weight once every 2 weeks.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | Intravenous infusion of 20 mg/kg of actual body weight once every 2 weeks, same as adult dosing. |
| Geriatric use | No specific dose adjustment; clinical studies included patients aged 65 and older with no observed differences in safety or efficacy. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NEXVIAZYME (NEXVIAZYME).
| Breastfeeding | It is not known whether sebelipase alfa is excreted in human milk. Many drugs are excreted in human milk, and caution should be exercised when administered to a nursing woman. M/P ratio not determined. |
| Teratogenic Risk | No adequate and well-controlled studies in pregnant women. In animal reproduction studies, intravenous administration of sebelipase alfa during organogenesis at doses up to 10 mg/kg (approximately 6 times the human exposure at the recommended dose based on AUC) produced maternal toxicity and increased post-implantation loss but no evidence of fetal malformations. Risk cannot be ruled out. |
■ FDA Black Box Warning
Risk of anaphylaxis and severe hypersensitivity reactions, including angioedema, bronchospasm, and cardiac arrest; acute cardiorespiratory failure may occur in patients with compromised cardiac or respiratory function.
| Serious Effects |
["History of life-threatening hypersensitivity reaction to avalglucosidase alfa or any excipient"]
| Precautions | ["Hypersensitivity reactions including anaphylaxis","Acute cardiorespiratory failure in susceptible patients","Risk of infusion-associated reactions (IARs)","Monitoring of vital signs during infusion","Premedication recommended for high-risk patients"] |
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| Fetal Monitoring | Monitor for infusion reactions (including anaphylaxis) during and after administration. Assess liver function tests (ALT, AST, bilirubin) and lipid profile periodically during pregnancy. Ultrasound monitoring for fetal growth and development if indicated by clinical condition. |
| Fertility Effects | No human data on fertility effects. In animal studies, no adverse effects on male or female fertility were observed at doses up to 10 mg/kg IV (approximately 6 times the human exposure). |