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Gene Therapy for X-linked Retinitis Pigmentosa (XLRP) - Retinitis Pigmentosa GTPase Regulator (RPGR)

Phase 1
Completed
Conditions
X-Linked Retinitis Pigmentosa
Interventions
Genetic: AAV2/5-RPGR
Registration Number
NCT03252847
Lead Sponsor
MeiraGTx UK II Ltd
Brief Summary

Phase 1 of the study is a dose escalation of the subretinal administration of AAV5-hRKp.RPGR vector to assess the safety of this vector in participants with XLRP caused by mutations in RPGR. Participants enrolled in Phase 1 were assigned to a dose group based on when they enrolled (i.e., sequential assignment).

Phase 2 of the study is a cohort expansion of the subretinal administration of AAV5-hRKp.RPGR vector to assess the safety and efficacy of this vector in participants with XLRP caused by mutations in RPGR. Participants enrolled in Phase 2 were randomized to immediate or deferred treatment.

Detailed Description

This is an open-label phase 1/2 dose-escalation and cohort expansion trial to determine the safety and efficacy of subretinal administration of AAV5-hRKp.RPGR vector in participants with XLRP caused by mutations in RPGR.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
49
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
SEQUENTIAL
Arm && Interventions
GroupInterventionDescription
Phase 2 (Part 2; Expansion)AAV2/5-RPGRParticipants receive one of two doses of AAV2/5-RPGR
Phase 1 (Part 1, Dose Escalation)AAV2/5-RPGRParticipants receive one of three doses of AAV2/5-RPGR
Primary Outcome Measures
NameTimeMethod
Number of Participants Meeting the Primary Outcome Defined as Any of the Below Events Occurring During the 9 Weeks Following Administration, at Least Possibly Related to the Advanced Therapy Investigational Medicinal Product (ATIMP), Not Surgery Alone.9 weeks

The primary outcome is defined as any of the below occurring during the 9 weeks following administration, at least possibly related to the Advanced Therapy Investigational Medicinal Product (ATIMP), not surgery alone:

* Reduction in visual acuity by 15 Early Treatment Diabetic Retinopathy Study (ETDRS) letters or more

* Severe unresponsive inflammation

* Infective endophthalmitis

* Ocular malignancy

* Grade III or above non-ocular Suspected Unexpected Serious Adverse Reaction (SUSAR)

Secondary Outcome Measures
NameTimeMethod
Improvements in Visual Function as Assessed by Visual AcuityBaseline and Month 6

Change from baseline to Week 26 in best corrected visual acuity (BCVA) using Early Treatment Diabetic Retinopathy Study (ETDRS) chart letter score. The direction of improvement from baseline is an increase in the number of ETDRS letters read over time.

Improvements in Retinal Function as Assessed by Static PerimetryBaseline and Month 6

The number of responders in point-by-point data in Static Perimetry within the full visual field over time.

A responder at a single time point is defined as a participant with at least 5 of the same loci with ≥7 dB improvement from baseline at the specific time point and one time point prior.

Quality of Life Measured by the Low Luminance Questionnaire (LLQ) Emotional Distress Domain ScoreBaseline and Month 6

Change from baseline to Week 26 in LLQ Emotional Distress Domain Score in adults. LLQ uses a scale from 0 to 100, with higher scores reflecting less impairment. A positive change from baseline reflects improvement, and a negative reflects worsening.

Quality of Life Measured by the Low Luminance Questionnaire (LLQ) Extreme Lighting Domain ScoreBaseline and Month 6

Change from baseline to Week 26 in LLQ Extreme Lighting Domain Score in adults. LLQ uses a scale from 0 to 100, with higher scores reflecting less impairment. A positive change from baseline reflects improvement, and a negative reflects worsening.

Quality of Life Measured by the Low Luminance Questionnaire (LLQ) General Dim Lighting Domain ScoreBaseline and Month 6

Change from baseline to Week 26 in LLQ General Dim Lighting Domain score in adults. LLQ uses a scale from 0 to 100, with higher scores reflecting less impairment. A positive change from baseline reflects improvement, and a negative reflects worsening.

Quality of Life Measured by the Low Luminance Questionnaire (LLQ) Mobility Domain ScoreBaseline and Month 6

Change from baseline to Week 26 in LLQ Mobility Domain Score in adults. LLQ uses a scale from 0 to 100, with higher scores reflecting less impairment. A positive change from baseline reflects improvement, and a negative reflects worsening.

Quality of Life Measured by the Low Luminance Questionnaire (LLQ) Peripheral Vision Domain ScoreBaseline and Month 6

Change from baseline to Week 26 in LLQ Peripheral Vision Domain Score in adults. LLQ uses a scale from 0 to 100, with higher scores reflecting less impairment. A positive change from baseline reflects improvement, and a negative reflects worsening.

Trial Locations

Locations (5)

Kellogg Eye Center

🇺🇸

Ann Arbor, Michigan, United States

Massachusetts Eye and Ear Institute

🇺🇸

Boston, Massachusetts, United States

Leeds Teaching Hospitals NHS Trust

🇬🇧

Leeds, United Kingdom

UPMC Eye Center

🇺🇸

Pittsburgh, Pennsylvania, United States

Moorfields Eye Hospital NHS Foundation Trust

🇬🇧

London, United Kingdom

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