An Extension Study to Assess the Long-term Safety and Efficacy of Hunterase (Idursulfase Beta)

NCT07344376 | Completed Phase 3

• 1 other identifier: GC1111_P3_Ex
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The objective of this study is to assess the long-term safety and efficacy of Hunterase for approximately 1 year in subjects who completed the end of study (EOS) visit (Visit 54) tests in the Phase 3 Hunterase study and patients who received Hunterase for more than 6 months

Conditions

MPS II; Hunter Syndrome (MPS II); Hunter Syndrome; Hunterase; GC1111

Keywords

Hunterase; GC1111; GC Biopharma; Long-term study; extension study

Outcome Measures

Primary Outcomes (4)

• Laboratory tests (CBC, Chemistry, Urinanalysis)

  Abnormality of Laboratory tests results

  Every visit until 12months

• Physical examination

  Abnormality of physical examination

  Every visit until 12months

• Adverse Event

  occurence, grade

  Every visit until 12months

• Electrocardiography

  Abnormality of ECG results

  Every 6 months until 12months

Secondary Outcomes (2)

• 6-minute walk test

  Every 4months until 12months

• Urine GAG (Heparan sulfate, Dermatan sulfate)

  Every visit until 12months

Study Arms (1)

Hunterase

OTHER

Single arm

Drug: Hunterase

Interventions

Hunterase DRUG

0.5mg/kg weekly IV administration

Also known as: GC1111

Hunterase

Eligibility Criteria

• Gender Eligibility Details: Male
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• Subject diagnosed with Hunter syndrome (MPS II) who completed activities at the EOS visit (Visit 54) in the GC1111\_P3 study
• (Subject who did not participate in the GC1111\_P3 study) Subject diagnosed with Hunter syndrome (MPS II) who received Hunterase for more than 6 months
• (Subjects who did not participate in the GC1111\_P3 study) Males aged ≥ 5
• Informed consent form voluntarily signed by the subject or by a legally acceptable representative
• Subject who agrees to use contraception

You may not qualify if:

• Subject with hypersensitivity to any of the ingredients of the investigational product
• Subject impossible to perform follow-up observation of the safety
• Subject who received the treatment with another investigational product within 14 days prior to the start of study drug
• Subject who plans to be treated with another investigational product during the study period
• Subject who has history of tracheostomy, bone marrow transplant, or cord blood transplant
• Any other inappropriate conditions for study participation at the investigator's discretion

Sponsors & Collaborators

• GC Biopharma Corp: lead
• Samsung Medical Center, Sungkyunkwan University School of Medicine: collaborator

Study Sites (1)

Samsung Medical Center

Seoul, South Korea

Location

MeSH Terms

Conditions

Sudden Infant Death; Mucopolysaccharidosis II

Condition Hierarchy (Ancestors)

Death, Sudden; Death; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Infant Death; X-Linked Intellectual Disability; Intellectual Disability; Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Genetic Diseases, X-Linked; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Heredodegenerative Disorders, Nervous System; Mucopolysaccharidoses; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; Lysosomal Storage Diseases; Mucinoses; Connective Tissue Diseases; Skin and Connective Tissue Diseases; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Phase 3 Extension study

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: January 15, 2026
• Study Start: May 23, 2018
• Primary Completion: December 30, 2022
• Study Completion: December 30, 2022
• Last Updated: January 15, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

KR (1)