Long-Term Follow-Up Gene Therapy Study for Achromatopsia CNGB3 and CNGA3

NCT03278873 | Terminated Results FDA Drug

• 2 other identifiers: MGT0072016-003856-59
• Study Type: observational
• Target: 34
• Locations: 2 countries
• Sites: 2

Brief Summary

This is a longer-term follow-up study of patients with achromatopsia associated with defects in CNGA3 who participated in a clinical trial in which they received AAV-CNGA3 retinal gene therapy, or of patients with achromatopsia associated with defects in CNGB3 who participated in a clinical trial in which they received AAV-CNGB3 retinal gene therapy.

Conditions

Achromatopsia

Keywords

Achromatopsia; CNGA3; CNGB3

Outcome Measures

Primary Outcomes (1)

• Incidence of Adverse Events Related to the Treatment

  The primary outcome measure is the longer-term safety of treatment with AAV-CNGA3 or AAV-CNGB3, assessed by the absence of IMP-related adverse events.

  5 Years

Secondary Outcomes (8)

• Improvements in Visual Function as Assessed by Visual Acuity at Month 12

  12 months

• Improvements in Visual Function as Assessed by Visual Acuity at Month 60

  60 months

• Improvements in Retinal Function as Assessed by Static Perimetry at Month 12

  12 months

• Improvements in Retinal Function as Assessed by Static Perimetry at Month 60

  60 months

• Quality of Life at Month 12 Measured by QoL Questionnaires in Children and Adolescents

  12 months

Study Arms (4)

Low dose of AAV-CNGA3 or AAV-CNGB3

Subretinal administration of a single low dose of AAV-CNGA3 or AAV-CNGB3

Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3

Intermediate dose of AAV-CNGA3 or AAV-CNGB3

Subretinal administration of a single intermediate dose of AAV-CNGA3 or AAV-CNGB3

Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3

Other dose of AAV-CNGA3 or AAV-CNGB3

Subretinal administration of a single other dose (between the intermediate and high dose) of AAV-CNGA3 or AAV-CNGB3

Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3

High dose of AAV-CNGA3 or AAV-CNGB3

Subretinal administration of a single high dose of AAV-CNGA3 or AAV-CNGB3

Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3

Interventions

Prior exposure to AAV-CNGA3 or AAV-CNGB3 BIOLOGICAL

Participants previously received AAV-CNGA3 or AAV-CNGB3 in an open-label, Phase 1/2 dose escalation trial for adults and children with achromatopsia owing to defects in CNGA3 or CNGB3, respectively.

High dose of AAV-CNGA3 or AAV-CNGB3; Intermediate dose of AAV-CNGA3 or AAV-CNGB3; Low dose of AAV-CNGA3 or AAV-CNGB3; Other dose of AAV-CNGA3 or AAV-CNGB3

Eligibility Criteria

• Age: 3 Years - 100 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population are adults and children with achromatopsia resulting from mutations in CNGA3 or CNGB3.

Inclusion in the study will be limited to individuals who: 1. Are able to give informed consent or assent, with or without the guidance of their parent(s)/guardian(s), where appropriate 2. Received AAV2/8-hCARp.hCNGB3 or AAV2/8-hG1.7p.coCNGA3 by intraocular administration in the prior open-label, Phase I/II, dose escalation study (EudraCT 2016-002290-35 or EudraCT 2018-003431-29) 3. Are willing to adhere to the protocol and long-term follow-up Individuals will be excluded who: Are unwilling or unable to meet the requirements of the study

Contact the study team to discuss eligibility requirements. They can help determine if this study is right for you.

Sponsors & Collaborators

• MeiraGTx UK II Ltd: lead

Study Sites (2)

Kellogg Eye Center

Ann Arbor, Michigan, 48105, United States

Location

Moorfields Eye Hospital NHS Foundation Trust

London, United Kingdom

Location

MeSH Terms

Conditions

Color Vision Defects

Condition Hierarchy (Ancestors)

Vision Disorders; Sensation Disorders; Neurologic Manifestations; Nervous System Diseases; Cone Dystrophy; Eye Diseases, Hereditary; Eye Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Limitations and Caveats

Upon agreement with the FDA, the study was prematurely terminated in March 2024. Therefore, the Month 60 data are not available for all participants.

Results Point of Contact

• Title: Program Manager
• Organization: MeiraGTx

ocularinfo@meiragtx.com

0044 (0)20 3866 4320

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: Yes

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 16, 2017
• First Posted: September 12, 2017
• Study Start: June 29, 2017
• Primary Completion: April 4, 2024
• Study Completion: April 4, 2024
• Last Updated: June 11, 2025
• Results First Posted: June 11, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1); GB (1)