RGX-121 Gene Therapy for Hunter Syndrome

Recruiting at 1 trial location

Overseen By Patient Advocacy

Age: < 18

Sex: Male

Trial Phase: Phase 1 & 2

Sponsor: REGENXBIO, Inc.

Must not be taking: AAV-based gene therapy

Disqualifiers: Neurocognitive deficit, Neuropsychiatric condition, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 40

Duration: 1 day

6 Participants Needed

Trial Summary

What is the purpose of this trial?

This trial tests RGX-121, a gene therapy designed to help children with severe MPS II by delivering a healthy gene to their brain cells. The goal is to produce an enzyme that can improve brain function. The study will check if this treatment is safe and effective. Brain-targeted hematopoietic stem cell gene therapy provides a promising therapy for MPS II patients.

Eligibility Criteria

This trial is for children over 5 with severe Hunter Syndrome, showing specific neurocognitive decline. They must have a genetic diagnosis of MPS II and not be responding to standard treatments. Kids can't join if they've had gene therapy before, are allergic to certain enzyme treatments, or have immune system issues that prevent them from taking immunosuppressants.

Inclusion Criteria

A family member has neuronopathic MPS II with the same mutation as mine, and a geneticist confirms I have inherited it.

I have MPS II and my neurocognitive test scores are below average.

I have MPS II and my brain function tests show a decline over time.

Exclusion Criteria

I cannot take immunosuppressive medications due to health reasons.

My body is not responding to ELAPRASE® due to certain antibodies.

I agree to stop my ELAPRASE® treatment via spinal injection for the study.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive a single dose of RGX-121 administered by IC or ICV injection

1 day

1 visit (in-person)

Primary Study Period

Safety is the primary focus for the initial 24 weeks after treatment

24 weeks

Visits at Week 1, Week 2, Week 4, Week 12, Week 24

Follow-up

Participants are monitored for safety and efficacy for up to a total of 104 weeks following treatment

80 weeks

Visits at Week 38, Week 52, Week 64, Week 78, Week 104

Treatment Details

Interventions

• RGX-121

Trial Overview The study tests RGX-121 gene therapy aimed at delivering a working IDS gene to the brain. It's in early stages (phase I/II) to see if it's safe and might work for kids with neuronopathic Hunter Syndrome who haven't improved on current therapies.

Participant Groups

Group I: Single Arm Experimental Treatment 1 Intervention

6.5 × 10\^10 GC/g brain mass of RGX-121

Who Is Running the Clinical Trial?

REGENXBIO, Inc.

Lead Sponsor

Trials

20

Recruited

2,800+

Regenxbio Inc.

Lead Sponsor

Trials

20

Recruited

2,800+

REGENXBIO Inc.

Lead Sponsor

Trials

25

Recruited

3,100+