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CompletedNCT03071965Updated May 9, 2025Results posted

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

A Phase 2 interventional study of Ciliary neurotrophic factor (CNTF) and Surgery in MacTel (Macular Telangiectasia) Type 2, sponsored by Neurotech Pharmaceuticals. Completed at 11 sites in 2 countries. Open to participants aged 21 Years to 80 Years. Per ClinicalTrials.gov, last updated 2025-05-09.

Sponsored by Neurotech Pharmaceuticals · Phase 2, Interventional, and Treatment

Phase
Phase 2
Study type
Interventional
Enrollment
70
Allocation
Non-randomized
Ages
21 Years to 80 Years
Sex
All
01

Study summary

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

02

Conditions studied

  • MacTel (Macular Telangiectasia) Type 2

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03

In context

Telangiectasis

69 studies on the registry are indexed under Telangiectasis; 12 are open to participants now.

This study's enrollment of 70 is above the median of 30 across 59 interventional studies indexed under Telangiectasis.

Browse Telangiectasis studies →

Lead sponsor

Neurotech Pharmaceuticals is the lead sponsor of 13 studies on the registry; 2 are open to participants now.

Of its 8 completed or terminated interventional studies of FDA-regulated products, 7 (88%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
21 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

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 form, agree to the form's contents, and provide written informed consent.

Exclusion criteria

Exclusion Criteria:

  • There are no Exclusion Criteria
Terms in these criteria, in plain language(1)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
70 participants (actual)

Study arms

  • 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) · Procedure: 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) · Procedure: Surgery

Interventions

  • BiologicalCiliary 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.

  • ProcedureSurgery

    Surgery to implant device for NT-501

  • ProcedureSurgery

    Sham surgery

06

What researchers measure

Primary outcomes

  1. 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

    Time frame: 72, 84, 96, and 108 months (based on participants' original implant date during precursor study)

  2. 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

    Time frame: Baseline to 36, 48, 60 and 72 Months post-surgery (based on participants' original implant date during precursor study)

Secondary outcomes

  1. 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.

    Time frame: Baseline to 72 Months (based on participants' original implant date)

  2. 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)

    Time frame: Baseline to 108 Months (based on participants' original implant date)

  3. 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

    Time frame: Baseline to 72 Months (based on participants' original implant date)

  4. 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

    Time frame: Baseline to 72 Months (based on participants' original implant date)

07

Results

Posted May 9, 2025

Participant flow

Participant flow — Overall Study
MilestoneCohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 Implant
Started6191530
Switched to nt-50101600
Retained nt-501 throughout the study6161430
Completed6181327
Not completed0123
Withdrew: Adverse event0010
Withdrew: Death0011
Withdrew: Covid-190101
Withdrew: Other health reason0001

Outcome measures

PrimaryEllipsoid 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

Time frame:
72, 84, 96, and 108 months (based on participants' original implant date during precursor study)
Reported as:
Mean · mm2
Ellipsoid Zone (Area of IS/OS Loss) - Cohort 1
mm2Cohort 1 - Fellow EyeCohort 1 - NT-501 Implant
Baseline0.697 ± 0.83340.629 ± 0.08135
72 Months Post-Surgery Actual1.37 ± 1.46481.137 ± 1.2905
72 Months Post-Surgery Change from Baseline0.620 ± 0.75260.508 ± 0.6348
84 Months Post-Surgery Actual1.241 ± 1.46911.132 ± 1.1194
84 Months Post-Surgery Change from Baseline0.705 ± 0.74740.503 ± 0.5001
96 Months Post-Surgery Actual1.338 ± 1.32641.169 ± 1.0987
96 Months Post-Surgery Change from Baseline0.642 ± 0.69220.540 ± 0.5159
108 Months Post-Surgery Actual0.394 ± 0.51560.301 ± 0.4909
108 Months Post-Surgery Change from Baseline0.165 ± 0.15580.277 ± 0.4605
PrimaryEllipsoid 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

Time frame:
Baseline to 36, 48, 60 and 72 Months post-surgery (based on participants' original implant date during precursor study)
Reported as:
Mean · mm2
Ellipsoid Zone (Area of IS/OS Loss) - Cohort 2
mm2Cohort 2 - NT-501 ImplantCohort 2 - Sham
Baseline0.684 ± 0.07070.766 ± 0.0687
Change at 36 Months Post-Surgery0.259 ± 0.06090.279 ± 0.0585
Change at 48 Months Post-Surgery0.360 ± 0.06090.282 ± 0.0589
Change at 60 Months Post-Surgery0.450 ± 0.06440.105 ± 0.0760
Change at 72 Months Post-Surgery0.443 ± 0.07280.497 ± 0.0680
Statistical analysis
  • Cohort 2 - NT-501 Implant vs Cohort 2 - Sham · Mixed Models Analysis · p = 0.5455 · Median difference (final values): -0.053 · 95% CI -0.226 to 0.120
SecondaryChange 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.

Time frame:
Baseline to 72 Months (based on participants' original implant date)
Reported as:
Mean · dB
Change in Retinal Sensitivity (dB) From Baseline - Cohort 2 Only
dBCohort 2 - NT-501 ImplantCohort 2 - Sham
Baseline25.688 ± 0.337725.672 ± 0.3317
Retinal Sensitivity Change at 36 Months Post-Surgery-1.391 ± 0.3377-1.054 ± 0.3320
Retinal Sensitivity Change at 48 Months Post-Surgery-2.312 ± 0.3376-1.965 ± 0.3319
Retinal Sensitivity Change at 60 Months Post-Surgery-2.912 ± 0.3562-2.369 ± 0.3347
Retinal Sensitivity Change at 72 Months Post-Surgery-3.047 ± 0.3674-2.909 ± 0.3595
SecondaryChange 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)

Time frame:
Baseline to 108 Months (based on participants' original implant date)
Reported as:
Mean · letters
Change in BCVA From Baseline for Cohort 1
lettersCohort 1 - Fellow EyeCohort 1 - NT-501 Implant
Baseline Actual80.5 ± 7.3475.0 ± 7.92
72 Months Post-Surgery Actual72.8 ± 11.9171.8 ± 7.76
72 Months Post-Surgery Change from Baseline-7.7 ± 7.23-3.2 ± 2.48
84 Months Post-Surgery Actual72.7 ± 9.3772.3 ± 6.65
84 Months Post-Surgery Change from Baseline-7.8 ± 4.83-2.7 ± 2.80
96 Months Post-Surgery Actual72.7 ± 8.8272.3 ± 6.22
96 Months Post-Surgery Change from Baseline-7.8 ± 3.43-2.7 ± 3.20
108 Months Post-Surgery Actual72.5 ± 8.3168.8 ± 10.30
108 Months Post-Surgery Change from Baseline-8.0 ± 3.74-6.2 ± 3.37
SecondaryChange 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

Time frame:
Baseline to 72 Months (based on participants' original implant date)
Reported as:
Mean · letters
Change in BCVA From Baseline for Cohort 2
lettersCohort 2 - NT-501 ImplantCohort 2 - Sham
Baseline77.2 ± 0.9777.0 ± 0.93
Change at 36 Months Post-Surgery-4.8 ± 0.80-3.2 ± 0.77
Change at 48 Months Post-Surgery-5.7 ± 0.81-3.9 ± 0.78
Change at 60 Months Post-Surgery-8.5 ± 0.82-3.9 ± 0.79
Change at 72 Months Post-Surgery-10.1 ± 0.87-6.9 ± 0.83
SecondaryChange 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

Time frame:
Baseline to 72 Months (based on participants' original implant date)
Reported as:
Mean · words per minute
Change in Reading Speed From Baseline - Cohort 2 Only
words per minuteCohort 2 - NT-501 ImplantCohort 2 - Sham
Baseline94.740 ± 6.4973107.222 ± 6.2866
Reading Speed Change at 36 Months Post-Surgery-8.838 ± 5.4428-17.798 ± 5.2686
Reading Speed Change at 48 Months Post-Surgery-18.931 ± 5.5846-25.488 ± 5.3072
Reading Speed Change at 60 Months Post-Surgery-28.627 ± 5.6369-18.324 ± 5.4825
Reading Speed Change at 72 Months Post-Surgery-24.713 ± 5.9294-34.478 ± 5.6311

Adverse events

Collected over Any serious AE occurring after surgery through study completion, up to 108 months based on participants original implant date. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Cohort 1 - Implant Only0/6 (0%)2/6 (33.3%)6/6 (100%)
Cohort 2 - Sham Only0/19 (0%)3/19 (15.8%)18/19 (94.7%)
Cohort 2 - NT-501 Implant1/15 (6.7%)4/15 (26.7%)14/15 (93.3%)
Cohort 2 - Sham + NT-501 Implant1/30 (3.3%)7/30 (23.3%)20/30 (66.7%)
Most frequent serious events
Showing 10 of 18
Most frequent serious events
EventCohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 Implant
Duodenal ulcer perforationGastrointestinal disorders1/60/190/150/30
Incarcerated herniaGeneral disorders1/60/190/150/30
Vascular pseudoaneurysmInjury, poisoning and procedural complications1/60/190/150/30
Metastatic neoplasmNeoplasms benign, malignant and unspecified (incl cysts and polyps)0/60/191/150/30
DiverticulitisInfections and infestations0/60/191/150/30
Non-infectious endophthalmitisEye disorders0/60/191/150/30
PainGeneral disorders0/60/191/150/30
Device expulsionProduct Issues0/60/191/150/30
Prostate cancerNeoplasms benign, malignant and unspecified (incl cysts and polyps)0/61/190/150/30
HyponatraemiaMetabolism and nutrition disorders0/61/190/150/30
Most frequent other events
Showing 10 of 138
Most frequent other events
EventCohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 Implant
CataractEye disorders0/64/192/150/30
Vitreous floatersEye disorders0/60/193/150/30
Dry eyeEye disorders1/60/192/150/30
Eye irritationEye disorders1/61/191/150/30
Cataract corticalEye disorders1/60/190/150/30
Conjunctivitis allergicEye disorders1/60/190/150/30
Dacryostenosis acquiredEye disorders1/60/190/150/30
Eye allergyEye disorders1/60/190/150/30
Periorbital dermatitisEye disorders1/60/190/150/30
InfluenzaInfections and infestations1/61/191/151/30

Baseline characteristics

Age, Categorical
Age, Categorical(Participants)Cohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 ImplantTotal
<=18 years00000
Between 18 and 65 years616101648
>=65 years0351422
Age, Continuous
Age, Continuous(years)Cohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 ImplantTotal
Mean53.8 ± 5.1259.4 ± 7.6159.5 ± 10.8263.6 ± 8.5961.4 ± 8.99
Sex: Female, Male
Sex: Female, Male(Participants)Cohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 ImplantTotal
Female41192044
Male2861026
Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)Cohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 ImplantTotal
Hispanic or Latino00112
Not Hispanic or Latino618142967
Unknown or Not Reported01001
Race (NIH/OMB)
Race (NIH/OMB)(Participants)Cohort 1 - Implant OnlyCohort 2 - Sham OnlyCohort 2 - NT-501 ImplantCohort 2 - Sham + NT-501 ImplantTotal
American Indian or Alaska Native00000
Asian11002
Native Hawaiian or Other Pacific Islander00000
Black or African American00011
White416112859
More than one race00000
Unknown or Not Reported12418
08

Study locations

11 sites
  • Stein Eye Institute / David Geffen School of Medicine
    Los Angeles, California 90095, United States
  • University of Miami-Miller School of Medicine, Bascom Palmer Eye Institute
    Miami, Florida 33136, United States
  • Emory University School of Medicine, Dept of Ophthalmology, Emory University Eye Center
    Atlanta, Georgia 30322, United States
  • NIH Clinical Center
    Rockville, Maryland 20892, United States
  • Massachusetts Eye and Ear Infirmary
    Boston, Massachusetts 02114, United States
  • University of Michigan, Kellogg Eye Center
    Ann Arbor, Michigan 48105, United States
  • Retina Associates of Cleveland, Inc
    Cleveland, Ohio 44122, United States
  • University of Wisconsin-Madison, Department of Ophthalmology and Visual Sciences
    Madison, Wisconsin 53705, United States
  • Sydney Eye Hospital
    Sydney, New South Wales 2000, Australia
  • Centre for Eye Research Australia
    East Melbourne, Victoria 3002, Australia
  • Lions Eye Institute
    Nedlands, Western Australia 6009, Australia
09

References and documents

Study documents

PDFs hosted by the registry, ClinicalTrials.gov.

Individual participant data

Plan to share: No

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on May 9, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT03071965
Lead sponsor
Neurotech Pharmaceuticals
Responsible party
Sponsor
First posted
Mar 7, 2017
Start date
May 12, 2017
Primary completion
May 11, 2021
Completion
May 11, 2021
Results posted
May 9, 2025
Last update
May 9, 2025

Study contacts

Thomas Aaberg, Jr, MD
study chair · Neurotech Pharmaceuticals, LLC

Oversight

FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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