WithdrawnPhase 4

A Study of ELAPRASE in Treatment-naïve Participants With Hunter Syndrome (Mucopolysaccharidosis [MPS] II)

Stopped: Study was closed due to enrollment challenges

United States0Started 2023-02-28

Plain-language summary

The main aim of this study is to evaluate the ability of a prophylactic immune tolerizing regimen (ITR) to prevent or reduce the development of high titer anti-idursulfase antibodies in treatment-naïve participants with Hunter syndrome. In this open label, single arm study, all participants will receive ELAPRASE treatment and a prophylactic ITR. Participants will be treated with ELAPRASE for up to 104 weeks. The prophylactic ITR will start 1 day prior to the start of ELAPRASE. The prophylactic ITR will consist of a 5-week cycle of: Rituximab (intravenously \[IV\], weekly for 4 weeks); Methotrexate (oral, 3 times per week for 5 weeks) and intravenous immunoglobulin (IVIG) (IV, every 4 weeks of the cycle). Following the completion of 1 cycle, an assessment will be made at Month 6, 12, and 18 regarding the need for administering another 5-week cycle of the ITR. Participants will be in the study for approximately 112 weeks (including 6 weeks for screening, up to 104 weeks for treatment, and 2 weeks for follow-up).

Who can participate

Age range6 Years

SexMALE

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Participant is male. * Participant is ELAPRASE-naïve at study entry. * Participant must have a documented diagnosis of MPS II. The following combination will be accepted as diagnostic of MPS II: * Participant has a deficiency in iduronate-2-sulfatase (I2S) enzyme activity of less than or equal to (\<=) 10 percent (%) of the lower limit of the normal range as measured in plasma, fibroblasts, or leukocytes (based on the reference laboratory's normal range). The participant has a normal enzyme activity level of at least 1 other sulfatase as measured in plasma, fibroblasts, or leukocytes (based on the reference laboratory's normal range). * Participant has a documented mutation in the IDS gene; additionally, participants must have a severe mutation (example, large deletion or complex gene rearrangement), which is predicted to lead to development of a persistent anti-idursulfase antibody response. * Participant will be less than (\<) 6 years of age at enrollment. * Participant has a negative test result for serum anti-idursulfase antibodies. Exclusion Criteria: * Participant has received treatment with any investigational drug within the 30 days prior to study entry. * Participant has received or is receiving treatment with idursulfase-IT. * Participant has received growth hormones, a cord blood infusion, or a bone marrow transplant at any time. * Participant has received blood product transfusions within 90 days prior to screening. * Participant is u…

What they're measuring

Rate of Anti-Idursulfase Antibodies Formation, Including Anti-Idursulfase Antibodies That Have Enzyme Neutralizing Activity

Timeframe: Up to 24 months

Trial details

NCT IDNCT05494593

SponsorTakeda

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-08-29