NCT04597385

Brief Summary

RGX-121-5101 is an observational long-term follow-up study to the RGX-121-101 or RGX-121-1102 studies where participants received RGX-121, a gene therapy intended to deliver a functional copy of the iduronate-2-sulfatase gene (IDS) to the central nervous system. This study will evaluate the long-term safety and efficacy of RGX-121.

Trial Health

78
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
27

participants targeted

Target at below P25 for all trials

Timeline
24mo left

Started Mar 2021

Longer than P75 for all trials

Geographic Reach
2 countries

4 active sites

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress74%
Mar 2021Oct 2028

First Submitted

Initial submission to the registry

October 15, 2020

Completed
7 days until next milestone

First Posted

Study publicly available on registry

October 22, 2020

Completed
5 months until next milestone

Study Start

First participant enrolled

March 14, 2021

Completed
7.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 1, 2028

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

October 1, 2028

Last Updated

August 19, 2026

Status Verified

August 1, 2026

Enrollment Period

7.6 years

First QC Date

October 15, 2020

Last Update Submit

August 17, 2026

Conditions

Mucopolysaccharidosis II

Keywords

MPS IIGene TherapyHunter

Outcome Measures

Primary Outcomes (1)

  • Long-term Safety of RGX-121

    To evaluate the safety of RGX-121 serious and adverse events as assessed by Common Terminology Criteria for Adverse Events (CTCAE Version 5.0).

    5 years inclusive of parent study

Secondary Outcomes (8)

  • Evaluate the long-term effect of RGX-121 on neurodevelopmental parameters of cognitive, motor, behavioral, and adaptive function (Bayley Scales of Infant and Toddler Development, 3rd Edition)

    5 years inclusive of parent study

  • Evaluate the long-term effect of RGX-121 on neurodevelopmental parameters of cognitive, motor, behavioral, and adaptive function (Kaufman Assessment Battery for Children, 2nd Edition)

    5 years inclusive of parent study

  • Evaluate the long-term effect of RGX-121 on neurodevelopmental parameters of cognitive, motor, behavioral, and adaptive function (Mullen Scales of Early Learning)

    5 years inclusive of parent study

  • Evaluate the long-term effect of RGX-121 on neurodevelopmental parameters of cognitive, motor, behavioral, and adaptive function (Vineland Adaptive Behavior Scales, 2nd Edition)

    5 years inclusive of parent study

  • Evaluate the long-term impact of RGX-121 on Plasma Biomarkers (I2S)

    5 years inclusive of parent study

  • +3 more secondary outcomes

Study Arms (1)

Long-term Follow-Up

No intervention.

Other: Long-term Follow-Up

Interventions

Long-term Follow-UpOTHER

No intervention

Long-term Follow-Up

Eligibility Criteria

Sexmale(Gender-based eligibility)
Gender Eligibility DetailsGenetic-based gender identity
Healthy VolunteersNo
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Up to 54 subjects who have received RGX-121 in a previous parent study.

You may qualify if:

  • To be eligible, a participant must have previously received RGX-121 in a separate parent trial.
  • Participant or participant's legal guardian(s) is/(are) willing and able to provide written, signed informed consent

You may not qualify if:

  • Participant has not received RGX-121 previously in a separate parent trial.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (4)

University of California, San Francisco (UCSF)- Benioff Children's Hospital

San Francisco, California, 94158, United States

Location

Saint Peter's Healthcare System

New Brunswich, New Jersey, 08901, United States

Location

The Children's Hospital of Philadelphia (CHOP)

Philadelphia, Pennsylvania, 19104, United States

Location

Hospital de Clinicas de Porto Alegre

Porto Alegre, 90035-903, Brazil

Location

MeSH Terms

Conditions

Mucopolysaccharidosis IISudden Infant Death

Condition Hierarchy (Ancestors)

X-Linked Intellectual DisabilityIntellectual DisabilityNeurobehavioral ManifestationsNeurologic ManifestationsNervous System DiseasesGenetic Diseases, X-LinkedGenetic Diseases, InbornCongenital, Hereditary, and Neonatal Diseases and AbnormalitiesHeredodegenerative Disorders, Nervous SystemMucopolysaccharidosesCarbohydrate Metabolism, Inborn ErrorsMetabolism, Inborn ErrorsLysosomal Storage DiseasesMucinosesConnective Tissue DiseasesSkin and Connective Tissue DiseasesMetabolic DiseasesNutritional and Metabolic DiseasesDeath, SuddenDeathPathologic ProcessesPathological Conditions, Signs and SymptomsInfant Death

Study Design

Study Type
observational
Observational Model
OTHER
Time Perspective
PROSPECTIVE
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

October 15, 2020

First Posted

October 22, 2020

Study Start

March 14, 2021

Primary Completion (Estimated)

October 1, 2028

Study Completion (Estimated)

October 1, 2028

Last Updated

August 19, 2026

Record last verified: 2026-08

Locations

US(3)BR(1)