Idursulfase

Hunter syndrome (Mucopolysaccharidosis II, MPS II) is an X-linked recessive disease caused by insufficient levels of the lysosomal enzyme iduronate-2-sulfatase. This enzyme cleaves the terminal 2- O -sulfate moieties from the glycosaminoglycans (GAG) dermatan sulfate and heparan sulfate.

• ELAPRASE is indicated for patients with Hunter syndrome (Mucopolysaccharidosis II, MPS II). ELAPRASE has been shown to improve walking capacity in patients 5 years and older.

• None. None.contraindicated

The recommended dosage is 0.5 mg per kg of body weight administered once every week as an intravenous infusion ( 2 ). 2.1 Recommended Dose The recommended dosage regimen of ELAPRASE is 0.5 mg per kg of body weight administered once weekly as an intravenous infusion. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. 2.2 Preparation Instructions Prepare and use ELAPRASE according to the following steps using aseptic technique: Determine the total volume of ELAPRASE to be administered and the number of vials needed based on the patient's weight and the recommended dose of 0.5 mg/kg. Patient's weight (kg) × 0.5 mg per kg of ELAPRASE ÷ 2 mg per mL = Total mL of ELAPRASE Total mL of ELAPRASE ÷ 3 mL per vial = Total number of vials Round up to the next whole vial to determine the total number of vials needed. Remove the required number of vials from the refrigerator to allow them to reach room temperature. Before withdrawing the ELAPRASE solution from the vial, visually inspect each vial for particulate matter and discoloration. The ELAPRASE solution should be clear to slightly opalescent and colorless. Do not use if the solution is discolored or if there is particulate matter in the solution. Do not shake the ELAPRASE solution. Withdraw the calculated volume of ELAPRASE from the appropriate number of vials. Add the calculated volume of ELAPRASE solution to a 100 mL bag of 0.9% Sodium Chloride Injection, USP for intravenous infusion. Mix gently. Do not shake the solution.

Hypersensitivity Reactions Including Anaphylaxis : Ensure that personnel administering product are adequately trained in cardio-pulmonary resuscitative measures and have ready access to emergency medical services (EMS) ( 5.1 ). Risk of Hypersensitivity, Serious Adverse Reactions, and Antibody Development in Hunter Syndrome Patients with Severe Genetic Mutations : Hunter syndrome patients aged 7 years and younger with complete gene deletion, large gene rearrangement, nonsense, frameshift, or splice site mutations experienced a higher incidence of hypersensitivity reactions, serious adverse reactions, and anti-idursulfase antibody development ( 5.2 ). Risk of Acute Respiratory Complications : Patients with compromised respiratory function or acute febrile or respiratory illness may be at higher risk of life-threatening complications from hypersensitivity reactions. Careful consideration should be given to the patient's clinical status prior to administration of ELAPRASE and consider delaying the ELAPRASE infusion ( 5.3 ). 5.1 Hypersensitivity Reactions Including Anaphylaxis Serious hypersensitivity reactions, including anaphylaxis, have occurred during and up to 24 hours after infusion. Some of these reactions were life-threatening and included respiratory distress, hypoxia, hypotension, urticaria, and angioedema of the throat or tongue, regardless of duration of the course of treatment. If anaphylactic or other acute reactions occur, immediately discontinue the infusion of ELAPRASE and initiate appropriate medical treatment.

The most common adverse reactions occurring in at least three patients (≥9%) aged five years and older were headache, pruritus, musculoskeletal pain, urticaria, diarrhea, and cough. The most common adverse reactions occurring in at least three patients (≥10%) aged seven years and younger were pyrexia, rash, vomiting, and urticaria. In all clinical trials, the most common adverse reactions requiring medical intervention were hypersensitivity reactions, and included rash, urticaria, pruritus, flushing, pyrexia, and headache ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Takeda Pharmaceuticals U.S.A., Inc. at 1-877-TAKEDA-7 (1-877-825-3327) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The following serious adverse reactions are described below and elsewhere in the labeling: Hypersensitivity Reactions Including Anaphylaxis [see Warnings and Precautions (5.1) ] In clinical trials, the most common adverse reactions (>10%) following ELAPRASE treatment were hypersensitivity reactions, and included rash, urticaria, pruritus, flushing, pyrexia, and headache.

8.1 Pregnancy Risk Summary There are no adequate and well-controlled studies with ELAPRASE use in pregnant women. Available data from a small number of postmarketing cases with ELAPRASE use in pregnancy are insufficient to inform drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes. In an animal reproduction study, no evidence of adverse effects on pre- and post-natal development was observed with twice weekly intravenous administration of idursulfase to pregnant rats from gestation day 6 through lactation day 19 at about 4 times the recommended human weekly dose of 0.5 mg/kg based on body surface area ( see Data ). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In a pre- and post-natal development study, idursulfase was administered to pregnant rats twice weekly, intravenously, from gestation day 6 through lactation day 19.

Metabolism

Clinical Trials in Patients 5 Years and Older The pharmacokinetic characteristics of idursulfase were evaluated in 59 patients with Hunter syndrome. The serum concentration of idursulfase was quantified using an antigen-specific ELISA assay.

One patient with Hunter syndrome, who received ELAPRASE at twice the recommended dosage for one and a half years, experienced two anaphylactic reactions over a 3-month period 4.5 years after initiating ELAPRASE treatment.

• Jul 24, 2006BLABLA125151Shire

1. 1Pyrexia60715%
2. 2Product Dose Omission Issue48112%
3. 3Inappropriate Schedule Of Product Administration40610%
4. 4Infusion Related Reaction3869.8%
5. 5Cough3067.8%
6. 6Pneumonia2967.6%
7. 7Death2676.8%
8. 8Dyspnoea2576.6%
9. 9Influenza2305.9%
10. 10Seizure2125.4%
11. 11Covid-192065.3%
12. 12Poor Venous Access1944.9%
13. 13Product Availability Issue1944.9%
14. 14Malaise1934.9%
15. 15Weight Increased1874.8%

The 10 most recently updated of 30 ClinicalTrials.gov registrations naming Idursulfase as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• A Phase III Study of JR-141 in Patients With Mucopolysaccharidosis II (STARLIGHT)
  Active not recruiting · Phase 3 · Interventional · 86 enrolled · JCR Pharmaceuticals Co., Ltd.
  NCT04573023updated 2026-06-04
• Post-trial Access Program of Idursulfase-IT Along With Elaprase in Children With Hunter Syndrome
  Available · Expanded access · Takeda
  NCT05795361updated 2026-04-13
• Long-term Evaluation on Height and Weight in Patients With MPS II Who Started Treatment at < 6 Years of Age
  Completed · Phase 4 · Interventional · 21 enrolled · Shire
  NCT02455622updated 2026-04-02
• PEARL (PrEnAtal Enzyme Replacement Therapy for Lysosomal Storage Disorders)
  Recruiting · Phase 1 · Interventional · 10 enrolled · University of California, San Francisco
  NCT04532047updated 2026-03-17
• An Extension Study to Assess the Long-term Safety and Efficacy of Hunterase (Idursulfase Beta)
  Completed · Phase 3 · Interventional · 30 enrolled · GC Biopharma Corp
  NCT07344376updated 2026-01-15
• A Study of ELAPRASE in Treatment-naïve Participants With Hunter Syndrome (Mucopolysaccharidosis [MPS] II)
  Withdrawn · Phase 4 · Interventional · 0 enrolled · Takeda
  NCT05494593updated 2025-12-09
• Extension Study of Idursulfase-IT Along With Elaprase in Children and Adults With Hunter Syndrome and Cognitive Impairment
  Active not recruiting · Phase 2 · Phase 3 · Interventional · 6 enrolled · Takeda
  NCT06031259updated 2025-11-06
• An Extension Study of HGT-HIT-045 Evaluating Long-Term Safety and Clinical Outcomes of Idursulfase-IT in Conjunction With Elaprase in Pediatric Participants With Hunter Syndrome and Cognitive Impairment
  Completed · Phase 1 · Phase 2 · Interventional · 15 enrolled · Takeda
  NCT01506141updated 2025-08-06
• A Study to Determine the Efficacy and Safety of Tividenofusp Alfa (DNL310) vs Idursulfase in Pediatric and Young Adult Participants With Neuronopathic (nMPS II) or Non-Neuronopathic Mucopolysaccharidosis Type II (nnMPS II)
  Recruiting · Phase 2 · Phase 3 · Interventional · 63 enrolled · Denali Therapeutics Inc.
  NCT05371613updated 2025-08-05
• Study of Long Term Safety and Clinical Outcomes of Idursulfase IT and Elaprase Treatment in Pediatric Participants Who Have Completed Study HGT-HIT-094
  Completed · Phase 2 · Phase 3 · Interventional · 56 enrolled · Shire
  NCT02412787updated 2025-06-19

Frequently asked questions

How does Idursulfase work?

Hunter syndrome (Mucopolysaccharidosis II, MPS II) is an X-linked recessive disease caused by insufficient levels of the lysosomal enzyme iduronate-2-sulfatase. This enzyme cleaves the terminal 2- O -sulfate moieties from the glycosaminoglycans (GAG) dermatan sulfate and heparan sulfate.

What is Idursulfase used for?

According to FDA labeling, Idursulfase carries indications including: ELAPRASE is indicated for patients with Hunter syndrome (Mucopolysaccharidosis II, MPS II). ELAPRASE has been shown to improve walking capacity in patients 5 years and older.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Idursulfase?

Idursulfase is classified as Enzymes, Hydrolytic Lysosomal Glycosaminoglycan-specific Enzyme, Glycosaminoglycan Metabolism Increase, Increased Lysosomal Function.

What are the brand names for Idursulfase?

Idursulfase is marketed under brand names including Elaprase.

What are the contraindications for Idursulfase?

Idursulfase labeling lists contraindications including: None. None.. Always consult the full prescribing information and a clinician.