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

This was a prospective, multicenter, single-masked, sham-controlled extension study designed to provide long-term safety and efficacy follow-up data for subjects with MacTel who had NT-501 implanted intraocularly and/or underwent sham surgery in the respective precursor study (NTMT-01 or NTMT-02).

A substudy was conducted in which subjects enrolled in study (NTMT-02), who had 1 study-eligible eye that underwent sham surgery, were offered the option to have NT-501 implanted in the same study eye. Of the 19 subjects who had 1 study-eligible eye and underwent sham surgery in the Cohort 2 precursor study (NTMT-02), 16 subjects elected to have NT-501 implanted in the same study eye during the substudy

Study Overview

• Status: Completed
• Conditions: MacTel (Macular Telangiectasia) Type 2
• Intervention / Treatment: Biological: Ciliary neurotrophic factor (CNTF); Procedure: Surgery; Procedure: Surgery

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Phase 2

Contacts and Locations

Study Locations

• Australia
  • New South Wales
    • Sydney, New South Wales, Australia, 2000
      • Sydney Eye Hospital
  • Victoria
    • East Melbourne, Victoria, Australia, 3002
      • Centre for Eye Research Australia
  • Western Australia
    • Nedlands, Western Australia, Australia, 6009
      • Lions Eye Institute
• United States
  • California
    • Los Angeles, California, United States, 90095
      • Stein Eye Institute / David Geffen School of Medicine
  • Florida
    • Miami, Florida, United States, 33136
      • University of Miami-Miller School of Medicine, Bascom Palmer Eye Institute
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Emory University School of Medicine, Dept of Ophthalmology, Emory University Eye Center
  • Maryland
    • Rockville, Maryland, United States, 20892
      • NIH Clinical Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts Eye and Ear Infirmary
  • Michigan
    • Ann Arbor, Michigan, United States, 48105
      • University of Michigan, Kellogg Eye Center
  • Ohio
    • Cleveland, Ohio, United States, 44122
      • Retina Associates of Cleveland, INC
  • Wisconsin
    • Madison, Wisconsin, United States, 53705
      • University of Wisconsin-Madison, Department of Ophthalmology and Visual Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 17 years to 76 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cohort 1; 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); 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.; Procedure: Surgery; Surgery to implant device for NT-501; Procedure: Surgery; Sham surgery
Experimental: Cohort 2; Participants completed protocol NTMT-02. Participants for cohort 2 arm were either: NT-501 group: included subjects who each had 1 study-eligible eye that had NT-501 implanted and a fellow eye that did not undergo any study intervention.; Sham group: included subjects who each had 1 study-eligible eye that underwent sham surgery and a fellow eye that did not undergo any study intervention.; Sham+NT-501 group: included subjects who had both eyes that were study-eligible, and had NT-501 implanted in 1 eye and underwent sham surgery in the contralateral eye.	Biological: Ciliary neurotrophic factor (CNTF); 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.; Procedure: Surgery; Surgery to implant device for NT-501; Procedure: Surgery; Sham surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ellipsoid Zone (Area of IS/OS Loss) - Cohort 1	Change from baseline to 72, 84, 96 and 108 months post-surgery (based on participants' original implant date during precursor study) by SD-OCT for Cohort 1	72, 84, 96, and 108 months (based on participants' original implant date during precursor study)
Ellipsoid Zone (Area of IS/OS Loss) - Cohort 2	Change in EZ from baseline to 36, 48, 60 and 72 Months post-surgery (based on participants' original implant date during precursor study). Cohort 2 sham surgery arm includes 16 participants (16 eyes) that received an NT-501 following their Month 36 follow-up	Baseline to 36, 48, 60 and 72 Months post-surgery (based on participants' original implant date during precursor study)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Retinal Sensitivity (dB) From Baseline - Cohort 2 Only	Baseline to 72 Months - analyses also presented for additional times: 36, 48, and 60 Months post-surgery (based on participants' original implant date during precursor study) . Cohort 2 sham surgery arm includes 16 participants (16 eyes) that received an NT-501 following their Month 36 follow-up in this study.	Baseline to 72 Months (based on participants' original implant date)
Change in BCVA From Baseline for Cohort 1	Baseline to 108 Months - analyses also presented for additional times: 84, 96 and 108 Months (based on participants' original implant date)	Baseline to 108 Months (based on participants' original implant date)
Change in BCVA From Baseline for Cohort 2	Baseline to 72 Months - analyses also presented for additional times: 36, 48, and 60 Months (based on participants' original implant date during precursor study) . Cohort 2 sham surgery arm includes 16 participants (16 eyes) that received an NT-501 following their Month 36 follow-up	Baseline to 72 Months (based on participants' original implant date)
Change in Reading Speed From Baseline - Cohort 2 Only	Baseline to 72 Months - analyses also presented for additional times: 36, 48, and 60 Months (based on participants' original implant date during precursor study) . Cohort 2 sham surgery arm includes 16 participants (16 eyes) that received an NT-501 following their Month 36 follow-up. Note: there were	Baseline to 72 Months (based on participants' original implant date)

Collaborators and Investigators

• Sponsor: Neurotech Pharmaceuticals
• Investigators: Study Chair: Thomas Aaberg, Jr, MD, Neurotech Pharmaceuticals, LLC

Study record dates

Study Major Dates

• Study Start (Actual): May 12, 2017
• Primary Completion (Actual): May 11, 2021
• Study Completion (Actual): May 11, 2021

Study Registration Dates

• First Submitted: March 1, 2017
• First Submitted That Met QC Criteria: March 1, 2017
• First Posted (Actual): March 7, 2017

Study Record Updates

• Last Update Posted (Actual): May 9, 2025
• Last Update Submitted That Met QC Criteria: May 7, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Telangiectasis
• Other Study ID Numbers: NTMT-01/02E

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No