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A Study to Determine the Safety and Efficacy of NT-501 in Macular Telangiectasia Type 2 - Protocol B

A Phase III Multicenter Randomized, Sham Controlled, Study to Determine the Safety and Efficacy of NT-501 in Macular Telangiectasia Type 2

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03319849
Enrollment
119
Registered
2017-10-24
Start date
2018-01-22
Completion date
2022-09-23
Last updated
2024-09-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Macular Telangiectasia Type 2

Keywords

Ciliary Neurotrophic Factor (CNTF), Macular Telangiectasia (MacTel), MacTel

Brief summary

This study is a phase 3, randomized, multi-center study to evaluate the efficacy and safety of the NT-501 implants in participants with macular telangiectasia type 2.

Detailed description

Phase 3, prospective, multicenter, masked, sham-controlled study with the overall study objective to evaluate the efficacy and safety of NT-501 for the treatment of MacTel. Secondary objective was to evaluate the safety of NT-501 in participants with MacTel. This was a multicenter study conducted at 20 study centers in the United States, Australia, Germany, and the United Kingdom.

Interventions

COMBINATION_PRODUCTNT-501

Each NT-501 implant consisted of hCNTF-secreting NTC-201-6A.02 cells encapsulated within supportive matrices and surrounded by a semipermeable polymer membrane. The NTC-201-6A cells continuously secrete CNTF from the NT-501 implant into the vitreous cavity. Implanted by a qualified Health Care Professional.

PROCEDURESham

The sham surgery involved a superficial conjunctival incision performed under local anesthetic and closure with a single suture.

Sponsors

The Lowy Medical Research Institute Limited
CollaboratorOTHER
Neurotech Pharmaceuticals
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)

Masking description

The subjects and all personnel at the image reading center remained masked to the treatment assignment throughout the study. In addition, the refractionist, VA examiner, and photographers/imagers were masked to treatment assignment (NT-501 implantation or sham procedure) at all follow-up visits. The ophthalmologist, surgeon, and clinic coordinator were instructed not to discuss the assigned treatment with the subject.

Intervention model description

After confirming eligibility in conjunction with the reading center, the study eye of each subject was randomized (1:1) to either have NT-501 implanted or to undergo the sham procedure.

Eligibility

Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
No

Inclusion criteria

Key Inclusion Criteria: 1. Participant must have at least one study eye with a positive diagnosis of MacTel with evidence of fluorescein leakage typical of MacTel and at least one of the other features that include hyperpigmentation that is outside of a 500 micron radius from the center of the fovea, retinal opacification, crystalline deposits, right-angle vessels, or inner/outer lamellar cavities 2. Participant must have an Inner Segment - Outer Segment Junction Line (IS/OS) Photo Receptor (PR) break in the study eye(s) and en face EZ (area of IS/OS loss) as measured by spectral-domain optical coherence tomography (SD-OCT) between 0.16 mm\^2 and 2.00 mm\^2 3. Participant's best corrected visual acuity (BCVA) is a 54-letter score or better (20/80 or better) as measured by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart at screening. 4. Participant must have steady fixation in the foveal or parafoveal area and sufficiently clear media for good quality photographs 5. Participant must be greater than 21 years of age or less than 80 years of age at screening 6. Participant must be able to provide written informed consent to participate in the study, in accordance with the International Conference on Harmonisation Good Clinical Practices guidelines, and local regulations, before initiating any study-related procedures 7. Women of childbearing potential must agree to use highly effective contraception (Germany and France only) Key

Exclusion criteria

1. Participant is medically unable to comply with study procedures or follow-up visits 2. Participant received intravitreal steroid therapy for non-neovascular MacTel within the last 3 months 3. Participant has ever received intravitreal anti-vascular endothelial growth factor (VEGF) therapy in the study eye OR has, within the past 3 months, received intravitreal anti-VEGF in the fellow eye at randomization 4. Participant has evidence of ocular disease other than MacTel that, in the judgment of the examining physician, may confound the diagnosis, procedures or outcome of the study (eg, glaucoma, severe nonproliferative or proliferative diabetic retinopathy, uveitis) 5. Participant has a chronic requirement (eg, ≥ 4 weeks at a time) for ocular medications and/or has a diagnosed disease that, in the judgment of the examining physician, may be vision threatening or may affect the primary outcome (artificial tears are permitted) 6. Participant has evidence of intraretinal neovascularization or subretinal neovascularization (SRNV), as evidenced by hemorrhage, hard exudate, subretinal fluid or intraretinal fluid in either eye 7. Participant has evidence of central serous chorio-retinopathy in either eye 8. Participant has evidence of pathologic myopia in either eye 9. Participant has significant corneal or media opacities in either eye 10. Participant has had a vitrectomy, penetrating keratoplasty, trabeculectomy, or trabeculoplasty 11. Participant has any of the following lens opacities: cortical opacity \> standard 3, posterior subcapsular opacity \> standard 2, or a nuclear opacity \> standard 3 as measured on the Age-Related Eye Disease Study (AREDS) clinical lens grading system 12. Participant has undergone lens removal in the previous 3 months or YAG laser within 4 weeks 13. Participant was a participant in any other clinical trial of an intervention (drug or device) within the last 6 months 14. Participant is on chemotherapy 15. Participant is pregnant or breastfeeding 16. Participant has a history of malignancy that would compromise the 24-month study survival 17. Participant with a history of ocular herpes virus in either eye 18. Participant has, in the opinion of the investigator, any physical or mental condition that would increase the risk of participation in the study or may interfere with the study procedures, evaluations, and outcome assessments 19. Participant has evidence of intraretinal hyperreflectivity by OCT

Design outcomes

Primary

MeasureTime frameDescription
The Rate of Change in the Area of EZ Area of Loss From Baseline Through Month 24End point timeframe is through Month 24. Baseline, Month 6, 12, 16, 20 and 24. Month 6 was collected but not included in the primary analyses.The rate of change in the area of EZ loss (IS/OS; macular photoreceptor loss) from baseline through month 24, as assessed using SD-OCT in the study eye of participants with MacTel.

Secondary

MeasureTime frameDescription
Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Baseline through 24 months.Change from baseline in retinal sensitivity loss as measured by as measured by Macular Integrity Assessment (MAIA)
Monocular Reading Speed (mITT Population)Baseline through 24 months.Change from baseline through Month 24 for Monocular reading speed assessed using International Reading Speed Texts (IReST) cards developed by the IReST Study Group 21

Countries

Australia, Germany, United States

Participant flow

Recruitment details

Screening period for up to 30 days

Pre-assignment details

119 subjects enrolled (6 participants withdrew after randomization) but prior to the implantation/sham surgery procedure; 59 subjects in NT-501 arm and 54 subjects in sham arm.

Participants by arm

ArmCount
NT-501
Test product NT-501: Each NT-501 implant consisted of hCNTF-secreting NTC-201-6A.02 cells encapsulated within supportive matrices and surrounded by a semipermeable polymer membrane. The NTC-201-6A cells continuously secrete CNTF from the NT-501 implant into the vitreous cavity. Implanted by a qualified Health Care Professional.
59
Sham
A sham surgical procedure was performed to mimic the implant procedure; there was no comparator product. Sham Procedure: The sham surgery involved a superficial conjunctival incision performed under local anesthetic and closure with a single suture.
54
Total113

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyAdverse Event10
Overall StudyCOVID-1901
Overall StudyEligible and did not enroll in amendment13
Overall StudyLost to Follow-up02
Overall StudyOther12
Overall StudyPhysician Decision01
Overall StudyWithdrawal by Subject01

Baseline characteristics

CharacteristicNT-501ShamTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
17 Participants18 Participants35 Participants
Age, Categorical
Between 18 and 65 years
42 Participants36 Participants78 Participants
Age, Continuous58.5 years
STANDARD_DEVIATION 7.61
58.7 years
STANDARD_DEVIATION 8.87
58.6 years
STANDARD_DEVIATION 8.2
Baseline Ocular Characteristics (mITT) - Area of EZ loss (mm^2)0.518 Area of EZ loss (mm^2)
STANDARD_DEVIATION 0.312
0.476 Area of EZ loss (mm^2)
STANDARD_DEVIATION 0.2934
0.498 Area of EZ loss (mm^2)
STANDARD_DEVIATION 0.3027
Baseline Ocular Characteristics (mITT) - Monocular Reading Speed96.49 words per minute
STANDARD_DEVIATION 47.314
94.09 words per minute
STANDARD_DEVIATION 42.806
95.36 words per minute
STANDARD_DEVIATION 45.051
Baseline Ocular Characteristics (mITT) - Ocular Visual Acuity74.4 Best-corrected visual acuity (letters)
STANDARD_DEVIATION 7.76
73.6 Best-corrected visual acuity (letters)
STANDARD_DEVIATION 9.23
74.0 Best-corrected visual acuity (letters)
STANDARD_DEVIATION 8.47
Baseline Ocular Characteristics (mITT) - Pupil Diameter3.53 Pupil diameter (mm)
STANDARD_DEVIATION 1.13
3.90 Pupil diameter (mm)
STANDARD_DEVIATION 1.092
3.70 Pupil diameter (mm)
STANDARD_DEVIATION 1.123
Ethnicity (NIH/OMB)
Hispanic or Latino
4 Participants4 Participants8 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
55 Participants49 Participants104 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants1 Participants1 Participants
Intraocular Pressure (mmHg)15.2 mmHg
STANDARD_DEVIATION 3.19
14.6 mmHg
STANDARD_DEVIATION 2.7
14.9 mmHg
STANDARD_DEVIATION 2.97
Natural Lens Present
No
7 Participants8 Participants15 Participants
Natural Lens Present
Yes
52 Participants46 Participants98 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
3 Participants1 Participants4 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants6 Participants7 Participants
Race (NIH/OMB)
White
55 Participants47 Participants102 Participants
Sex: Female, Male
Female
46 Participants36 Participants82 Participants
Sex: Female, Male
Male
13 Participants18 Participants31 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
1 / 590 / 54
other
Total, other adverse events
56 / 5948 / 54
serious
Total, serious adverse events
11 / 5910 / 54

Outcome results

Primary

The Rate of Change in the Area of EZ Area of Loss From Baseline Through Month 24

The rate of change in the area of EZ loss (IS/OS; macular photoreceptor loss) from baseline through month 24, as assessed using SD-OCT in the study eye of participants with MacTel.

Time frame: End point timeframe is through Month 24. Baseline, Month 6, 12, 16, 20 and 24. Month 6 was collected but not included in the primary analyses.

Population: The efficacy and safety of the NT-501 implant that delivers a daily dose of CNTF in comparison to sham surgery with no implant, in participants with confirmed MacTel.

ArmMeasureValue (MEAN)Dispersion
NT-501The Rate of Change in the Area of EZ Area of Loss From Baseline Through Month 240.111 mm^2Standard Error 0.0142
ShamThe Rate of Change in the Area of EZ Area of Loss From Baseline Through Month 240.160 mm^2Standard Error 0.0149
p-value: 0.018695% CI: [-0.089, -0.0082]Mixed Models Analysis
Secondary

Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)

Change from baseline in retinal sensitivity loss as measured by as measured by Macular Integrity Assessment (MAIA)

Time frame: Baseline through 24 months.

Population: All treated participants (mITT population)

ArmMeasureGroupValue (MEAN)Dispersion
NT-501Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Baseline Actual55.54 dBStandard Deviation 56.05
NT-501Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Change from Baseline40.02 dBStandard Deviation 51.278
NT-501Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Actual97.77 dBStandard Deviation 78.62
ShamMean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Baseline Actual51.84 dBStandard Deviation 57.38
ShamMean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Change from Baseline41.97 dBStandard Deviation 41.111
ShamMean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Actual93.02 dBStandard Deviation 70.414
Aggregate Interpolated Retinal Sensitivity Loss (dB) - NT-501Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Actual61076.49 dBStandard Deviation 52619.379
Aggregate Interpolated Retinal Sensitivity Loss (dB) - NT-501Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Baseline Actual34864.17 dBStandard Deviation 35305.26
Aggregate Interpolated Retinal Sensitivity Loss (dB) - NT-501Mean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Change from Baseline24859.88 dBStandard Deviation 31165.862
Aggregate Interpolated Retinal Sensitivity Loss (dB) - ShamMean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Baseline Actual32445.03 dBStandard Deviation 38667.79
Aggregate Interpolated Retinal Sensitivity Loss (dB) - ShamMean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Change from Baseline26309.32 dBStandard Deviation 25374.04
Aggregate Interpolated Retinal Sensitivity Loss (dB) - ShamMean Change in Aggregate Retinal Sensitivity Loss and Aggregate Interpolated Retinal Sensitivity Loss by Microperimetry (mITT Population)Month 24 Actual58360.26 dBStandard Deviation 50535.07
Secondary

Monocular Reading Speed (mITT Population)

Change from baseline through Month 24 for Monocular reading speed assessed using International Reading Speed Texts (IReST) cards developed by the IReST Study Group 21

Time frame: Baseline through 24 months.

Population: All treated participants (mITT population) without missing data

ArmMeasureGroupValue (MEAN)Dispersion
NT-501Monocular Reading Speed (mITT Population)Baseline Actual96.49 Reading Speed (words per minute)Standard Deviation 47.314
NT-501Monocular Reading Speed (mITT Population)Month 24 Actual92.18 Reading Speed (words per minute)Standard Deviation 45.09
NT-501Monocular Reading Speed (mITT Population)Month 24 Change from Baseline-5.46 Reading Speed (words per minute)Standard Deviation 29.648
ShamMonocular Reading Speed (mITT Population)Baseline Actual94.09 Reading Speed (words per minute)Standard Deviation 42.806
ShamMonocular Reading Speed (mITT Population)Month 24 Actual77.33 Reading Speed (words per minute)Standard Deviation 43.899
ShamMonocular Reading Speed (mITT Population)Month 24 Change from Baseline-18.88 Reading Speed (words per minute)Standard Deviation 33.705

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026