Extension Study of Idursulfase-IT Along With Elaprase in Children and Adults With Hunter Syndrome and Cognitive Impairment

An Open-Label Extension for Subjects in Studies HGT-HIT-046 and SHP609-302 Evaluating Long-Term Safety of Intrathecal Idursulfase-IT Administered in Conjunction With Intravenous Elaprase® in Subjects With Hunter Syndrome and Cognitive Impairment

The study is an extension of two previous studies (HGT-HIT-046 [NCT01506141] and SHP609-302 [NCT02412787]). Participants must have completed one of the previous studies. The main aim of this study is to collect more information about the safety of the treatments, idursulfase-IT and elaprase, in children and adults with Hunter syndrome and cognitive impairment. Participants will receive the same treatment as in the previous studies.

Study Overview

• Status: Active, not recruiting
• Conditions: Hunter Syndrome
• Intervention / Treatment: Drug: Idursulfase-IT; Drug: Elaprase

Detailed Description

The drug being tested in this study is called idursulfase. Idursulfase is being tested for long term safety in participants with Hunter syndrome and cognitive impairment.

The study will enroll up to approximately 8 patients. Participants will receive idursulfase-IT via intrathecal drug delivery device (IDDD) once monthly along with elaprase intravenous (IV) infusion, weekly.

This multi-center trial will be conducted in France and Canada. The overall time to participate in this study is approximately 4.8 years.

• Study Type: Interventional
• Enrollment (Actual): 6
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2E 7Z4
      • M.A.G.I.C. Clinic
  • British Columbia
    • Vancouver, British Columbia, Canada, V6T1Z3
      • University of British Columbia
  • Ontario
    • Toronto, Ontario, Canada, M5G1X8
      • Hospital for Sick Children
• France
  • Auvergne-Rhône-Alpes
    • Bron, Auvergne-Rhône-Alpes, France, 02 69229
      • Hopital Femme Mere Enfant

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. The participant must have completed end of study assessments in studies HGT-HIT-046 [NCT01506141] or SHP609-302 [NCT02412787] and received a clinical benefit from idursulfase-IT in the opinion of the investigator.
2. The participant, or participant's legally designated representative, must have been informed of the nature of this open-label extension and must have voluntarily signed an Institutional Review Board (IRB)/Independent Ethics Committee (IEC) approved informed consent form after all relevant aspects of the study have been explained and discussed. Written consent of the participant's legally designated representative (if applicable) and the participant's consent/assent, as relevant, must be obtained.
3. The participant has continued to receive elaprase on a regular basis in studies HGT-HIT-046 or SHP609-302.

Exclusion Criteria:

1. The participant has experienced, in the opinion of the investigator, a safety or medical issue that contraindicates treatment with idursulfase-IT, including, but not limited to, uncontrolled seizure disorder, bleeding disorder, and clinically relevant hypertension.
2. The participant has clinically relevant intracranial hypertension.
3. The participant is enrolled in another clinical study, other than studies HGT-HIT-046 or SHP609-302, that involves clinical investigations or use of any investigational product (drug or [intrathecal/spinal] device) within 30 days prior to study enrolment or at any time during the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Idursulfase-IT; Participants will receive idursulfase-IT once monthly and weekly IV infusions of elaprase at the dose used in previous studies (HGT-HIT-045/SHP609-302) via IDDD until benefit is no longer derived from the treatment, or treatment is no longer tolerable, or up to approximately 4.8 years.	Drug: Idursulfase-IT; Idursulfase-IT intrathecally via IDDD.; Drug: Elaprase; Elaprase IV infusion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants with Adverse Events (AEs) by Type and Severity	An adverse event (AE) means any untoward medical occurrence in a participant or participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. The severity of AEs will be determined per the investigator's assessment.	Up to approximately 4.8 years
Number of Participants with AEs Related to Idursulfase-IT	An AE means any untoward medical occurrence in a participant or participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. Any adverse event related to idursulfase-IT will be reported in this outcome measure.	Up to approximately 4.8 years
Number of Participants with AEs Related to the IDDD	An AE means any untoward medical occurrence in a participant or participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. Any adverse event related to the IDDD will be reported in this outcome measure.	Up to approximately 4.8 years
Number of Participants with AEs Related to Device Surgical Procedure	An AE means any untoward medical occurrence in a participant or participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. Any adverse event related to device surgical procedure will be reported in this outcome measure.	Up to approximately 4.8 years
Number of Participants with AEs Related to IT Administration Process	An AE means any untoward medical occurrence in a participant or participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. Any adverse event related to IT administration process will be reported in this outcome measure.	Up to approximately 4.8 years
Number of Participants with AEs Related to IV Elaprase Infusion	An AE means any untoward medical occurrence in a participant or participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. Any adverse event related to IV elaprase infusion will be reported in this outcome measure.	Up to approximately 4.8 years

Collaborators and Investigators

• Sponsor: Takeda
• Investigators: Study Director: Study Director, Takeda

Publications and helpful links

Helpful Links

• To obtain more information on the study, click here on this link

Study record dates

Study Major Dates

• Study Start (Actual): March 5, 2024
• Primary Completion (Estimated): January 1, 2029
• Study Completion (Estimated): January 1, 2029

Study Registration Dates

• First Submitted: September 4, 2023
• First Submitted That Met QC Criteria: September 4, 2023
• First Posted (Actual): September 11, 2023

Study Record Updates

• Last Update Posted (Estimated): November 6, 2025
• Last Update Submitted That Met QC Criteria: November 5, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Drug Therapy
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Metabolic Diseases; Connective Tissue Diseases; Neurobehavioral Manifestations; Heredodegenerative Disorders, Nervous System; Intellectual Disability; Genetic Diseases, X-Linked; Carbohydrate Metabolism, Inborn Errors; Lysosomal Storage Diseases; Mucinoses; Mucopolysaccharidoses; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Nutritional and Metabolic Diseases; Skin and Connective Tissue Diseases; X-Linked Intellectual Disability; Mucopolysaccharidosis II; idursulfase
• Other Study ID Numbers: TAK-609-3001; 2023-504127-90-00 (Ctis: EU CTIS Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Takeda does not provide access to Individual Participant Data when a study is in a very limited (small) study population due to participant privacy concerns such as potential reidentification of study participants.
• IPD Sharing Access Criteria: IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/. For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes