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Active, not recruiting

NCT Number: NCT04597385

Long-term Follow-Up for RGX-121

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.

Active, not recruiting

This study is active but is not currently recruiting participants.

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Key information

Conditions

Mucopolysaccharidosis II Carbohydrate Metabolism, Inborn Errors Congenital, Hereditary, and Neonatal Diseases and Abnormalities Connective Tissue Diseases Death Death, Sudden Genetic Diseases, Inborn Genetic Diseases, X-Linked Heredodegenerative Disorders, Nervous System Infant Death Intellectual Disability Lysosomal Storage Diseases Metabolic Diseases Metabolism, Inborn Errors Mucinoses Mucopolysaccharidoses Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations Nutritional and Metabolic Diseases Pathologic Processes Pathological Conditions, Signs and Symptoms Skin and Connective Tissue Diseases Sudden Infant Death X-Linked Intellectual Disability

Sex eligibility

Male

Study type

Observational

Primary location

Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil

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About this study

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 or RGX-121-1102 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). No treatment will be administered 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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

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

Treatment and study plan

Long-term Follow-Up

Other

No intervention

Primary outcomes

  1. Long-term Safety of RGX-121

    Time frame: 5 years inclusive of parent study

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

Secondary outcomes

  1. 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)

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term effect of RGX-121 on neurodevelopmental parameters as measured by the BSID-III. The BSID-III assesses children aged 1 to 42 months across several domains (cognitive, language, and motor domains) to give a holistic view of the participants' development and potential delays.

  2. 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)

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term effect of RGX-121 on neurodevelopmental parameters as measured by the KABC-II. The KABC-II is an individually administered measure of the cognitive processing abilities of children and adolescents aged 3 through 18.

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

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term effect of RGX-121 on neurodevelopmental parameters as measured by the MSEL. The MSEL is a standardized developmentally integrated system that assesses language, motor, and perceptual abilities, and measures cognitive ability and motor development.

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

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term effects of RGX-121 on neurodevelopmental parameters as measured by the VABS-II. The VABS-II assesses adaptive behavior in individuals from infancy to age 90 years. The VABS-II offers a way to measure personal and social self-sufficiency in real-life situations and to observe how these cognitive abilities impact the autonomy management process when put into practice

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

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term impact of RGX-121 on Plasma biomarker Iduronate-2-sulfatase (I2S) through plasma collection for participants not receiving ERT (discontinued or naïve).

  6. Evaluate the long-term impact of RGX-121 on CSF Biomarkers (I2S)

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term impact of RGX-121 on CSF Biomarker Iduronate-2-sulfatase (I2S) through lumbar puncture.

  7. Evaluate the long-term impact of RGX-121 on CSF Biomarkers (GAGs)

    Time frame: 5 years inclusive of parent study

    To evaluate long-term impact of RGX-121 on CSF Biomarker Glycosaminoglycans (GAGs) through lumbar puncture.

  8. Long-term effect of RGX-121 on Urine Biomarker (GAGs)

    Time frame: 5 years inclusive of parent study

    To evaluate the long-term impact of RGX-121 on Urine Biomarker Glycosaminoglycans (GAGs) through urine analysis.

Sponsors and collaborators

Lead sponsor

REGENXBIO Inc.

Industry

Registry information

Official study title

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

Important dates

Study start
2021
Primary completion
2028
Study completion
2028
First posted
Oct 22, 2020
Registry last updated
Aug 19, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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