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Phase 4 Study: Long-term Safe...

Phase 4 Study: Long-term Safety and Efficacy of NT-501 in MacTel Type 2, Including Sham Procedure Participants

NCT ID: NCT06971939

Last Updated: 2025-07-09

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

NOT_YET_RECRUITING

Clinical Phase

PHASE4

Total Enrollment

285 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-08-15

Study Completion Date

2030-08-15

Brief Summary

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The purpose of this global, multicenter, open-label, Phase 4 clinical extension study is to evaluate the long-term safety and efficacy of revakinagene taroretcel-lwey (Encelto™; hereinafter referred to as NT-501), in participants with macular telangiectasia type 2 (MacTel) who previously received the intraocular implant in a Phase 1, Phase 2, or Phase 3 clinical study. In addition, this study will evaluate the safety and efficacy of NT501 in participants who previously underwent the sham procedure in a Phase 3 MacTel clinical study and elect to have NT-501 implanted intraocularly in this Phase 4 study.

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Detailed Description

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This extension study consists of 3 arms:

* Arm 1 (Phase 3 Treated Participants' Long-term Follow-up): Arm 1 is to assess the long-term safety and efficacy of NT-501 in participants who received NT-501 in a previous MacTel Phase 3 clinical study (NTMT-03-A or NTMT-03-B).
* Arm 2 (Phase 1 and Phase 2 Long-term Follow-up): Similar to Arm 1, Arm 2 is to assess the long-term safety of NT-501 in participants who received NT-501 in a previous MacTel Phase 1 or Phase 2 clinical study (NTMT-01, NTMT-02, or NTMT-01/02E).
* Arm 3 (Phase 3 Sham to Implant Crossover): Arm 3 will evaluate the safety and efficacy of NT-501 in participants who previously underwent the sham procedure in a Phase 3 MacTel clinical study (NTMT-03-A or NTMT-03-B) and elect to have NT-501 implanted intraocularly in this extension study.

Arms 1 and 2 are noninterventional and observational studies. Participants who received NT-501 in both eyes (ie, participated in study NTMT-02B) will be enrolled in either Arm 1 or Arm 2 based on the study in which the first NT-501 was implanted (ie, participants who received the first implant in a Phase 3 study will be enrolled in Arm 1 and those who received the first implant in the Phase 1 study or Phase 2 study will be enrolled in Arm 2).

Only Arm 3 is an interventional study where participants will receive an NT-501 implant. A participant can receive NT-501 in either eye that meets eligibility criteria according to investigator assessment, and in accordance with participant choice.

Conditions

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Macular Telangiectasia Type 2 (MacTel)

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Arms 1 and 2: For participants who previously received a single NT-501, the implanted eye is designated the study eye. For participants who received an NT-501 implant in both eyes (ie. the first implant received in NTMT-01, NTMT-02, NTMT 01/02E, NTMT-03-A, or NTMT-03-B, and the second implant received in NTMT-02B), both eyes will be designated as study eyes (the eye in which NT-501 was originally implanted will be study eye 1 and the other implanted eye will be study eye 2).

Arm 3: The implanted eye will be designated as the study eye in Arm 3. Note, if NT-501 in not implanted in the Sham eye (ie. the eye that did not undergo intervention during the parent Phase 3 clinical study), then the sham eye will also be considered a study eye for long-term follow-up.

Regardless of study eye designation, both eyes of each participant in all 3 study arms will be evaluated during the study.

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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Arm 1 (Phase 3 Long-term Follow-up)

For participants who received NT-501 (ENCELTO) in a previous Phase 3 study (NTMT-03-A or NTMT-03-B), or for participants who received NT-501 (ENCELTO) in both eyes (i.e. participated in study NTMT-02B) but received the first NT-501 (ENCELTO) implant in a Phase 3 study. No new treatment intervention will be administered. Arm 2 is focused on long term follow-up for participant who already has the ENCELTO implant at time of study screening and enrollment.

Group Type OTHER

NT-501/revakinagene taroretcel-lwey

Intervention Type COMBINATION_PRODUCT

NT-501 is surgically implanted into the vitreous cavity to continuously release recombinant human ciliary neurotrophic factor (CNTF).

Arm 2 (Phase 1 and Phase 2 Long-term Follow-up)

For participants who received NT-501 (ENCELTO) in a previous Phase 1 study (NTMT-01), Phase 2 study (NTMT-02), in the sub study of Phase 1 and Phase 2 extension study (NTMT-01/02E), or for participants who received NT-501 (ENCELTO) in both eyes (i.e. participated in study NTMT-02B) but received the first NT-501 (ENCELTO) implant in a Phase 1 or Phase 2 study. No new treatment intervention will be administered. Arm 2 is focused on long term follow-up for participant who already has the ENCELTO implant at time of study screening and enrollment.

Group Type OTHER

NT-501/revakinagene taroretcel-lwey

Intervention Type COMBINATION_PRODUCT

NT-501 is surgically implanted into the vitreous cavity to continuously release recombinant human ciliary neurotrophic factor (CNTF).

Arm 3 (Phase 3 Sham to Implant Crossover)

For participants who underwent Sham procedure in either Phase 3 study (NTMT-03-A or NTMT-03-B) and will receive NT-501 in this study.

Group Type EXPERIMENTAL

NT-501/revakinagene taroretcel-lwey

Intervention Type COMBINATION_PRODUCT

NT-501 is surgically implanted into the vitreous cavity to continuously release recombinant human ciliary neurotrophic factor (CNTF).

Interventions

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NT-501/revakinagene taroretcel-lwey

NT-501 is surgically implanted into the vitreous cavity to continuously release recombinant human ciliary neurotrophic factor (CNTF).

Intervention Type COMBINATION_PRODUCT

Other Intervention Names

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ENCELTO

Eligibility Criteria

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Inclusion Criteria

To be eligible to participate in this study, an individual participant must meet all the following criteria:

1. Male or female adult participants who previously completed an NT-501 MacTel clinical study and:

1. Arm 1: received NT-501 intraocular implant in either Phase 3 study (NTMT-03-A or NTMT-03-B)
2. Arm 2: received NT-501 intraocular implant in the Phase 1 study (NTMT-01), Phase 2 study (NTMT-02), or in the substudy of the Phase 1 and Phase 2 extension study (NTMT-01/02E)

Note: participants who received NT-501 in both eyes (ie, participated in study NTMT-02B) will be enrolled in either Arm 1 or Arm 2 based on the study in which the first NT 501 was implanted (ie, participants who received the first implant in a Phase 3 study will be enrolled in Arm 1 and those who received the first implant in the Phase 1 study or Phase 2 study will be enrolled in Arm 2).
3. Arm 3: underwent the sham procedure in either Phase 3 study (NTMT-03-A or NTMT-03-B)
2. Participants must have steady fixation in the foveal or parafoveal area and sufficiently clear media for good quality retinal imaging.
3. Participant or their legally authorized representative must be able to provide written informed consent to participate in the study, in accordance with the International Conference on Harmonisation (ICH) Good Clinical Practice (GCP) guidelines, and local regulations, before initiating any clinical study related procedures.
4. Arm 3: female participants of childbearing potential must agree to use highly effective contraception. Highly effective forms of contraception (generally a first-year typical use pregnancy risk of 1% or less) include the following: contraceptive implants; an intrauterine device; permanent contraceptive procedures (vasectomy, bilateral salpingectomy, bilateral tubal occlusion, or partial salpingectomy); abstinence. A combination of male condom with either cap, diaphragm, or sponge with spermicide (ie, double barrier methods) is also considered an acceptable, but not highly effective, method of birth control.

Note: Participants enrolled at investigator sites in France or Germany must agree to use 2 forms of contraception listed above during study participation.

Exclusion Criteria

1. Participant is medically unable to comply with clinical study procedures or visits.
2. 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.

3. Participant has significant corneal or media opacities in the study eye to be implanted.
4. Participant has evidence of pathologic myopia in the study eye to be implanted.
5. Participant has any of the following lens opacities in the study eye to be implanted: 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. Note: the participant can be reconsidered for enrollment 90 days after undergoing cataract surgery.
6. Participant has undergone lens removal in the study eye to be implanted in the previous 3 months or YAG laser within 4 weeks of the screening/baseline visit.
7. Participant has evidence of ocular disease in the study eye to be implanted 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).
8. Received intravitreal steroid therapy in the study eye to be implanted within the last year.
9. Received intravitreal anti-vascular endothelial growth factor therapy in the study eye to be implanted within the last 6 months.
10. Evidence of active exudative intraretinal neovascularization or subretinal neovascularization in the study eye to be implanted, as evidenced by hemorrhage, hard exudate, subretinal fluid, or intraretinal fluid.
11. Evidence of central serous chorioretinopathy in the study eye to be implanted.
12. Participant underwent vitrectomy, penetrating keratoplasty, trabeculectomy, or trabeculoplasty in the study eye to be implanted.
13. A history of ocular herpes virus in the study eye to be implanted.
14. Participant is on chemotherapy.
15. Participant is pregnant or breastfeeding.
16. Participation in any other clinical study of an intervention (drug or device) within 6 months prior to the screening/baseline visit.
17. A history of malignancy that would compromise survival during the clinical study.

Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers