Long-term Follow-Up for RGX-121

A Long-term Follow-up Study to Evaluate the Safety and Efficacy of RGX-121

RGX-121-5101 is the long-term follow-up study to the RGX-121-101 first in human study 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.

Study Overview

• Status: Enrolling by invitation
• Conditions: Mucopolysaccharidosis II
• Intervention / Treatment: Other: Long-term Follow-Up

Detailed Description

This is a prospective follow-up study to evaluate the long-term safety and efficacy after a single administration of RGX-121. Eligible participants are those who previously have enrolled in clinical study RGX-121-101 and received a single intracisternal (IC) or intracerebroventricular (ICV) infusion of RGX-121. Enrollment of each participant will occur the same day or after the participant has completed the end of study (EOS) visit or early termination visit (ET) from the previous (parent) study. Participants will be followed in this study cumulatively for up to 5 years after RGX-121 administration (inclusive of the parent study) or until RGX-121 is commercially available in the participant's country, whichever occurs first. No treatment will be directed under this observational protocol. The total study duration for each participant may vary depending on when they enroll in the current study following RGX-121 administration in the parent study.

• Study Type: Observational
• Enrollment (Anticipated): 12

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Pittsburgh, Pennsylvania, United States, 15224
      • Children's Hospital of Pittsburgh - UPMC: Program for Neurodevelopment in Rare Disorders

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 2 years and older (ADULT, OLDER_ADULT, CHILD)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

• Sampling Method: Non-Probability Sample

Study Population

Up to 12 subjects over the age of 28 months who have received RGX-121 in a previous study.

Description

Inclusion Criteria:

• 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

Exclusion Criteria:

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

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Long-term Follow-Up; No intervention.	Other: Long-term Follow-Up; No intervention

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidences of Adverse Events over time.	Safety	3 years
Incidences of Serious Adverse Events over time	Safety	3 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biomarkers [Time frame: 1 Month, 12 Months, 24 Months, 36 Months]	Change from baseline in Glycosaminoglycan levels (ng/mL)	3 years
Changes in neurodevelopmental parameters of cognitive function [Time Frame: 1 Month, 12 Months, 24 Months, 36 Months]	Change from baseline in neurodevelopment parameters of cognitive, behavioral and adaptive function as measured by the Bayley Scales of Infant and Toddler Development, 3rd Edition (BSID-III) or Kaufman Assessment Battery for Children, 2nd Edition (KABC-II).	3 years
Changes in neurodevelopmental parameters of cognitive function [Time Frame: 1 Month, 12 Months, 24 Months, 36 Months]	Change from baseline in neurodevelopment parameters of cognitive, behavioral and adaptive function as measured by the Mullen Scales of Early Learning (MSEL)	3 years
Changes in neurodevelopmental parameters of adaptive behavior function [Time Frame: 1 Month, 12 Months, 24 Months, 36 Months]	Vineland Adaptive Behavior Scales Second Edition (VABS-II)	3 years

Collaborators and Investigators

• Sponsor: REGENXBIO Inc.

Study record dates

Study Major Dates

• Study Start (ACTUAL): March 14, 2021
• Primary Completion (ANTICIPATED): September 1, 2025
• Study Completion (ANTICIPATED): September 1, 2025

Study Registration Dates

• First Submitted: October 15, 2020
• First Submitted That Met QC Criteria: October 15, 2020
• First Posted (ACTUAL): October 22, 2020

Study Record Updates

• Last Update Posted (ACTUAL): August 10, 2021
• Last Update Submitted That Met QC Criteria: August 9, 2021
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Keywords: Gene Therapy; MPS II; Hunter
• Additional Relevant MeSH Terms: Metabolic Diseases; Nervous System Diseases; Neurologic Manifestations; Neurobehavioral Manifestations; Genetic Diseases, Inborn; Genetic Diseases, X-Linked; Connective Tissue Diseases; Carbohydrate Metabolism, Inborn Errors; Metabolism, Inborn Errors; Lysosomal Storage Diseases; Mucinoses; Mental Retardation, X-Linked; Intellectual Disability; Heredodegenerative Disorders, Nervous System; Mucopolysaccharidosis II; Mucopolysaccharidoses
• Other Study ID Numbers: RGX-121-5101

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No