ELAPRASE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ELAPRASE (ELAPRASE).
Idursulfase is a recombinant form of iduronate-2-sulfatase, the enzyme deficient in Hunter syndrome (MPS II). It hydrolyzes 2-sulfate groups from the terminal iduronate sulfate glycosaminoglycans (GAGs) dermatan sulfate and heparan sulfate, thereby reducing GAG accumulation in tissues.
| Metabolism | Metabolized via peptide hydrolysis to small peptides and amino acids. |
| Excretion | Renal: negligible; primarily catabolized via peptide hydrolysis to amino acids, which are reused or excreted |
| Half-life | Terminal half-life: 6.5–8.5 hours (mean 7.5 h) in pediatric patients; supports weekly IV dosing |
| Protein binding | Not protein bound (negligible binding to plasma proteins) |
| Volume of Distribution | Vd: 0.24–0.36 L/kg (mean 0.30 L/kg), approximating extracellular fluid volume |
| Bioavailability | IV: 100% (not administered via other routes) |
| Onset of Action | IV: clinical improvement in urinary glycosaminoglycan levels observed within 2–4 weeks |
| Duration of Action | Weekly IV dosing maintains reduced urinary GAG levels; sustained effects with continued treatment |
0.58 mg/kg IV once weekly administered over 1 hour
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment recommended; clinical trials included patients with renal impairment; monitor renal function |
| Liver impairment | No hepatic impairment studies; use with caution in severe hepatic impairment |
| Pediatric use | 0.58 mg/kg IV once weekly; same as adult dose based on body weight |
| Geriatric use | No specific dose adjustment; use same weight-based dosing as adults; monitor for infusion reactions |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ELAPRASE (ELAPRASE).
| Breastfeeding | No data on presence in human milk, effects on breastfed infant, or milk production. Endogenous IgG is present in milk; however, systemic absorption from oral intake is minimal. Consider developmental and health benefits of breastfeeding along with mother's clinical need for ELAPRASE. |
| Teratogenic Risk | FDA Pregnancy Category C. In animal studies, no evidence of teratogenicity at doses up to 3 times the human dose. No adequate human data; risk cannot be ruled out. Fetal exposure likely due to placental transfer of IgG1 monoclonal antibodies in second and third trimesters. Potential for fetal harm unknown. |
■ FDA Black Box Warning
Anaphylaxis and severe allergic reactions have occurred during and after infusions, including life-threatening anaphylactic shock. Patients should be monitored closely during infusion and have appropriate medical support available.
| Serious Effects |
["History of severe hypersensitivity reactions, including anaphylaxis, to idursulfase or any of its excipients."]
| Precautions | ["Risk of anaphylaxis and severe allergic reactions; premedication may be considered.","Infusion reactions (e.g., urticaria, angioedema, hypotension, respiratory distress) require management and possible interruption of infusion.","Sleep apnea and upper airway obstruction: evaluate airway patency, especially in patients with pre-existing respiratory compromise.","Hypersensitivity to any component of the product."] |
Loading safety data…
| Fetal Monitoring | No specific monitoring required; standard prenatal care. Monitor for infusion-related reactions. No known fetal monitoring indicated. |
| Fertility Effects | No human data on fertility. In animal studies, no adverse effects on male or female fertility observed. |