AchromatopsiaNCT03278873
Long-Term Follow-Up Gene Therapy Study for Achromatopsia CNGB3 and CNGA3
An observational study of Achromatopsia, run by MeiraGTx UK II Ltd at 2 sites in 2 countries.
Trial 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… Read more about this study
- Who is it for?
- Ages 3 to 100 years
- Conditions the study is for
- Achromatopsia
- What is being tested?
- Prior exposure to AAV-CNGA3 or AAV-CNGB3
- How many people
- 34 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 29 Jun 2017to 4 Apr 2024
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 3 to 100 years
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: The study population are adults and children with achromatopsia resulting from mutations in CNGA3 or CNGB3.
Who may be able to join
- Are able to give informed consent or assent, with or without the guidance of their parent(s)/guardian(s), where appropriate
- 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)
- 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
Who cannot join
None listed.
Trial locations and contacts
2 sites in 2 countries.
2 sites in 2 countries
United Kingdom1 site
Moorfields Eye Hospital NHS Foundation Trust
London
About this study
Official title: Long-term Follow-up Study of Participants Following an Open Label, Multi-centre, Phase I/II Dose Escalation Trial of a Recombinant Adeno-associated Virus Vector (AAV2/8-hCARp.hCNGB3 and AAV2/8-hG1.7p.coCNGA3) for Gene Therapy of Adults and Children With Achromatopsia Owing to Defects in CNGB3 or CNGA3
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.
Read the detailed description
The follow-up study is designed to collect data on the longer-term safety and efficacy of AAV-CNGA3 retinal gene therapy and AAV-CNGB3 retinal gene therapy.
- Conditions
- Achromatopsia
- Being tested
- Prior exposure to AAV-CNGA3 or AAV-CNGB3
- Keywords
- Achromatopsia, CNGA3, CNGB3
- Medical subject headings
- Color Vision Defects
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Prior exposure to AAV-CNGA3 or AAV-CNGB3Biological
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.
| Study group | Role | What they receive |
|---|---|---|
| Low dose of AAV-CNGA3 or AAV-CNGB3 | Subretinal administration of a single low dose of AAV-CNGA3 or AAV-CNGB3 Receives: 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 Receives: 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 Receives: 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 Receives: Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3 |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 5 Years
Secondary outcomes (8)
Improvements in Visual Function as Assessed by Visual Acuity at Month 12
Change from baseline to Month 12 in best corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study (ETDRS) chart letter score in the treated eye. The direction of improvement from baseline is an increase in the number of ETDRS letters read over time.
Measured: 12 months
Improvements in Visual Function as Assessed by Visual Acuity at Month 60
Change from baseline to Month 60 in best corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study (ETDRS) chart letter score in the treated eye. The direction of improvement from baseline is an increase in the number of ETDRS letters read over time.
Measured: 60 months
Improvements in Retinal Function as Assessed by Static Perimetry at Month 12
Change from baseline to Month 12 in contrast sensitivity in the treated eye. The direction of improvement is an increase in sensitivity.
Measured: 12 months
Improvements in Retinal Function as Assessed by Static Perimetry at Month 60
Change from baseline to Month 60 in contrast sensitivity in the treated eye. The direction of improvement is an increase in sensitivity.
Measured: 60 months
Quality of Life at Month 12 Measured by QoL Questionnaires in Children and Adolescents
Change from baseline to Month 12 in EuroQol-5D-Y Visual Analogue Scale (EQ-VAS) in children and adolescents. EQ-VAS uses a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state. A positive change from baseline reflects improvement, and a negative change from baseline reflects worsening.
Measured: 12 months
Quality of Life at Month 60 Measured by QoL Questionnaires in Children and Adolescents
Change from baseline to Month 60 in EuroQol-5D-Y Visual Analogue Scale (EQ-VAS) in children and adolescents. EQ-VAS uses a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state. A positive change from baseline reflects improvement, and a negative change from baseline reflects worsening.
Measured: 60 months
Quality of Life at Month 12 Measured by QoL Questionnaires in Adults
Change from baseline to Month 12 in EuroQol-5D-5L Visual Analogue Scale (EQ-VAS) in adults. EQ-VAS uses a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state. A positive change from baseline reflects improvement, and a negative change from baseline reflects worsening.
Measured: 12 months
Quality of Life at Month 60 Measured by QoL Questionnaires in Adults
Change from baseline to Month 60 in EuroQol-5D-5L Visual Analogue Scale (EQ-VAS) in adults. EQ-VAS uses a scale from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state. A positive change from baseline reflects improvement, and a negative change from baseline reflects worsening.
Measured: 60 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Sep 2017
- Study start29 Jun 2017
- Primary completion4 Apr 2024
- Study completion4 Apr 2024
Why it stopped: Strategic decision to not further develop AAV8-hCARp.hCNGB3 and AAV8-hG1.7p.coCNGA3. The decision is not due to safety concerns.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for AchromatopsiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 34 participants (actual)
Sponsor and investigators
- Lead sponsor
- MeiraGTx UK II Ltd
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03278873
- Sponsor's protocol ID
- MGT007
- Other IDs
- 2016-003856-59, 2016
- Status last verified
- Jun 2025
- First submitted
- 16 Aug 2017
- Last updated
- 11 Jun 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-term Follow-up Study of Participants Following an Open Label, Multi-centre, Phase I/II Dose Escalation Trial of a Recombinant Adeno-associated Virus Vector (AAV2/8-hCARp.hCNGB3 and AAV2/8-hG1.7p.coCNGA3) for Gene Therapy of Adults and Children With Achromatopsia Owing to Defects in CNGB3 or CNGA3
- ClinicalTrials.gov ID
- NCT03278873
- Acronym / sponsor ID
- MGT007
- Conditions
- Achromatopsia
- Keywords
- Achromatopsia, CNGA3, CNGB3
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: Strategic decision to not further develop AAV8-hCARp.hCNGB3 and AAV8-hG1.7p.coCNGA3. The decision is not due to safety concerns.
- Enrolment
- 34 participants (actual)
- Lead sponsor
- MeiraGTx UK II LtdIndustry (pharma, biotech, devices)
- Study start
- 29 Jun 2017 (actual)
- Primary completion
- 4 Apr 2024 (actual)
- Study completion
- 4 Apr 2024 (actual)
- First posted
- 12 Sep 2017 (actual)
- Results
- Posted 11 Jun 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
The follow-up study is designed to collect data on the longer-term safety and efficacy of AAV-CNGA3 retinal gene therapy and AAV-CNGB3 retinal gene therapy.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Low dose of AAV-CNGA3 or AAV-CNGB3 | – | Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3Subretinal administration of a single low dose of AAV-CNGA3 or AAV-CNGB3 |
| Intermediate dose of AAV-CNGA3 or AAV-CNGB3 | – | Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3Subretinal administration of a single intermediate dose of AAV-CNGA3 or AAV-CNGB3 |
| Other dose of AAV-CNGA3 or AAV-CNGB3 | – | Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3Subretinal administration of a single other dose (between the intermediate and high dose) of AAV-CNGA3 or AAV-CNGB3 |
| High dose of AAV-CNGA3 or AAV-CNGB3 | – | Biological: Prior exposure to AAV-CNGA3 or AAV-CNGB3Subretinal administration of a single high dose of AAV-CNGA3 or AAV-CNGB3 |
Who may qualify
- Ages
- 3 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- The study population are adults and children with achromatopsia resulting from mutations in CNGA3 or CNGB3.
Key inclusion criteria (5 listed)
- Are able to give informed consent or assent, with or without the guidance of their parent(s)/guardian(s), where appropriate
- 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)
- Are willing to adhere to the protocol and long-term follow-up
- Are unwilling or unable to meet the requirements of the study
Key exclusion criteria (0 listed)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Prior exposure to AAV-CNGA3 or AAV-CNGB3Participants 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. | Biological | 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 |
Primary outcome
Incidence of Adverse Events Related to the Treatment
Time frame: 5 Years
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.
8 secondary outcomes
Improvements in Visual Function as Assessed by Visual Acuity at Month 12
Time frame: 12 months
Improvements in Visual Function as Assessed by Visual Acuity at Month 60
Time frame: 60 months
Improvements in Retinal Function as Assessed by Static Perimetry at Month 12
Time frame: 12 months
Improvements in Retinal Function as Assessed by Static Perimetry at Month 60
Time frame: 60 months
Quality of Life at Month 12 Measured by QoL Questionnaires in Children and Adolescents
Time frame: 12 months
Quality of Life at Month 60 Measured by QoL Questionnaires in Children and Adolescents
Time frame: 60 months
Quality of Life at Month 12 Measured by QoL Questionnaires in Adults
Time frame: 12 months
Quality of Life at Month 60 Measured by QoL Questionnaires in Adults
Time frame: 60 months
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Achromatopsia, run by MeiraGTx UK II Ltd at 2 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 11 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 11 Jun 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Adverse Events Related to the Treatment (time frame: 5 Years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2025.