CNGB1 and Allied Disorders

Recruiting

• Conditions: Retinitis Pigmentosa Associated With CNGB1 Mutations

• Registration Number: NCT04639635
• Lead Sponsor: Columbia University

Brief Summary

Mutations in the rod-expressed gene, cyclic nucleotide-gated channel beta subunit (CNGB1) and associated inborn errors in metabolism are causes of retinal disease that causes progressive loss of vision. Retinitis pigmentosa (RP) is a major cause of untreatable blindness associated with CNGB1 (CNGB1-RP). RP involves the death of photoreceptor cells that can be caused by mutations in a number of different genes. Treatment by gene therapy could prevent blindness in cases of inherited retinal dystrophies including RP. In the future RP due to mutations in CNGB1 may be treatable by gene therapy since this form of photoreceptor degeneration involves a slow loss of rod photoreceptor cells. This provides a wide window of opportunity for the identification of patients and initiation of treatment. Our efforts are directed toward developing gene therapy as a treatment. To this end, our objective is to better understand the disease process of CNGB1-RP and other allied inherited disorders so that we can develop clinical tests to measure the outcomes of treatment.

Detailed Description

Not available

Study Timeline

• Study Start: 2019-03-14
• Study First Submitted: 2020-08-07
• Study First Submitted QC: 2020-11-16
• Study First Posted: 2020-11-20
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-25
• Last Update Posted: 2025-04-29
• Primary Completion: 2026-02
• Study Completion: 2026-02

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Diagnosis of CNGB1-associated RP by study physician, who are trained retinal specialists in the university clinic
• Must be able to commit to 4 follow-up study visits (3 years)

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Optical Coherence Tomography (OCT)	1 time per year, for 3 years
We will be looking to identify what the best outcome measurements will be for CNGB1-RP in order to use these measurements in a future clinical trial.	2 days, 1 time per year, for 3 years	Both structural imaging and functional tests will be used to characterize the natural history progression of CNGB1-RP.
Fundus Autofluorescence (FAF)	1 time per year, for 3 years
Near-infrared fundus autofluorescence (NIR-AF)	1 time per year, for 3 years
Quantitative Fundus Autofluorescence (qAF)	1 time per year, for 3 years
Full-field ERG (ISCEV Protocol)	1 time per year, for 3 years
Medmont Dark Adapted Chromatic (DAC) Automated Perimeter	1 time per year, for 3 years

Secondary Outcome Measures

Name	Time	Method
MAIA Microperimetry	1 time per year, for 3 years	if available
NIDEK Microperimetry	1 time per year, for 3 years	if available
Complete Ophthalmic Exam	2 time per year, for 3 years
Color Fundus Photos	1 time per year, for 3 years
Panel D-15 Colour Vision (desat.)	1 time per year, for 3 years
Best-corrected Visual Acuity (BCVA)	1 time per year, for 3 years
Goldman Kinetic Visual Field	1 time per year, for 3 years
Light-adapted Static Perimetry	1 time per year, for 3 years
Dark-adapted Chromatic Perimetry	1 time per year, for 3 years
Full-field Stimulus Testing (FST)	1 time per year, for 3 years	Optional

Trial Locations

Locations (6)

Dr. Stephen H. Tsang; 🇺🇸 New York, New York, United States

Institut de la Vision/Centre de maladies rares du Centre Hospitalier National Ophtalmologique des Quinze-Vingts; 🇫🇷 Paris, France

Wills Eye Hospital; 🇺🇸 Philadelphia, Pennsylvania, United States

Moorfields Eye Hospital NHS Foundation Trust; 🇬🇧 London, United Kingdom

Klinikum der Universität München University Eye Hospital, Ludwig-Maximilians-University (LMU) Munich; 🇩🇪 München, Bavaria, Germany

Eberhard Karls University Tubingen; 🇩🇪 Tuebingen, Germany