Extension Study of NT-501 Ciliary Neurotrophic Factor (CNTF) Implant for Macular Telangiectasia (MacTel)

Study Overview
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Brief Summary
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This study is a prospective, phase 2 extension study of participants previously enrolled in NTMT-01 and NTMT-02. This study is designed to evaluate long term safety and efficacy of the NT-501 implant in participants previously enrolled in the NTMT-01 and NTMT-02 protocols.

Official Title
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Extension Study of NT-501 Ciliary Neurotrophic Factor (CNTF) Implant for Macular Telangiectasia (MacTel)

Conditions
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Macular Telangiectasia

Intervention / Treatment
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* Biological: Ciliary neurotrophic factor (CNTF)
* Procedure: Surgery
* Procedure: Surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Previously enrolled in the NTMT-01 or NTMT-02 protocol and received the NT-501 implant and/or underwent a Sham procedure Participant must be offered sufficient opportunity to review and to understand the informed consent form, agree to the form's contents, and provide written informed consent. Exclusion Criteria: There are no Exclusion Criteria

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cohort 1<br>Participants completed protocol NTMT-01. All participants received surgery to implant NT-501. All participants received ciliary neurotrophic factor (CNTF). | Biological: Ciliary neurotrophic factor (CNTF)<br>* The investigational product is the NT-501 encapsulated cell system, which consists of cells encapsulated within a semi-permeable polymer membrane and supportive matrices. NT-501 contains NTC-201 cells that secrete recombinant human CNTF, which were derived from genetically modified NTC-200 cells.<br>Procedure: Surgery<br>* Surgery to implant device for NT-501<br>|
| Experimental: Cohort 2<br>Participants completed protocol NTMT-02. Participants received surgery to implant NT-501 or sham surgery to mimic implant procedure. Participants that received NT-501 implant were exposed to ciliary neurotrophic factor (CNTF). | Biological: Ciliary neurotrophic factor (CNTF)<br>* The investigational product is the NT-501 encapsulated cell system, which consists of cells encapsulated within a semi-permeable polymer membrane and supportive matrices. NT-501 contains NTC-201 cells that secrete recombinant human CNTF, which were derived from genetically modified NTC-200 cells.<br>Procedure: Surgery<br>* Surgery to implant device for NT-501<br>Procedure: Surgery<br>* Sham surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ellipsoid zone (area of IS/OS loss) | Change from baseline to 36, 48, 60, 72 months as measured by SD-OCT for Cohort 2 | 36, 48, 60, and 72 months | 
| Ellipsoid zone (area of IS/OS loss) | Change from baseline to 72, 84, 96, and 108 months as measured by SD-OCT for Cohort 1 | 72, 84, 96, and 108 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retinal sensitivity (dB) | Change from baseline to 36, 48, 60, and 72 months as measured by microperimetry for Cohort 2 | 36, 48, 60, and 72 months | 
| Retinal sensitivity (dB) | Change from baseline to 72, 84, 96, and 108 months as measured by microperimetry for Cohort 1 | 72, 84, 96, and 108 months | 
| Increase in ellipsoid zone (area of IS/OS loss) | Proportion of study eyes with a 35% or more increase from baseline at 36, 48, 60, and 72 months for Cohort 2 | 36, 48, 60, and 72 months | 
| Increase in ellipsoid zone (area of IS/OS loss) | Proportion of study eyes with a 35% or more increase from baseline at 72, 84, 96, and 108 months for Cohort 1 | 72, 84, 96, and 108 months | 
| Visual acuity | Change in best corrected visual acuity from baseline to 36, 48, 60, and 72 months for Cohort 2 | 36, 48, 60, and 72 months | 
| Visual acuity | Change in best corrected visual acuity from baseline to 72, 84, 96, and 108 months for Cohort 1 | 72, 84, 96, and 108 months | 
| Visual acuity | Proportion of study eyes with 15 or more letter loss in BCVA from baseline to 36, 48, 60, and 72 months for Cohort 2 | 36, 48, 60, and 72 months | 
| Visual acuity | Proportion of study eyes with 15 or more letter loss in BCVA from baseline to 72, 84, 96, and 108 months for Cohort 1 | 72, 84, 96, and 108 months | 
| Visual acuity | Proportion of study eyes with 10 or more letter loss in BCVA from baseline to 36, 48, 60, and 72 months for Cohort 2 | 36, 48, 60, and 72 months | 
| Visual acuity | Proportion of study eyes with 10 or more letter loss in BCVA from baseline to 72, 84, 96, and 108 months for Cohort 1 | 72, 84, 96, and 108 months | 
| Reading speed | Change from baseline to 36, 48, 60, and 72 months in reading speed as measured by IReST for Cohort 2 | 36, 48, 60, and 72 months | 
| Reading speed | Change from baseline to 72, 84, 96, and 108 months in reading speed as measured by IReST for Cohort 1 | 72, 84, 96, and 108 months |