Phase 4 Study: Long-term Safety and Efficacy of NT-501 in MacTel Type 2, Including Sham Procedure Participants
A Phase 4, Multicenter, Open-label Study to Evaluate Long-term Safety and Efficacy of Revakinagene Taroretcel-Lwey (NT-501) Previously Implanted During a Phase 1, Phase 2, or Phase 3 Clinical Study and to Evaluate NT-501 Implanted in Participants Who Underwent the Sham Procedure in a Phase 3 Clinical Study of Macular Telangiectasia Type 2 (MacTel)
- Macular Telangiectasia Type 2 (MacTel)
At a glance
- Phase
- Phase 4
- Study type
- Interventional
- Sponsor
- Neurotech Pharmaceuticals
- Enrolment target
- 234
- Started
- 21 November 2025
- Main results due
- 15 January 2032
- Study sites
- 26
- Registry updated
- 25 September 2026
Can you take part?
- Aged 18 years and over.
- Open to any sex.
- You need the condition being studied — healthy volunteers are not accepted.
These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.
Read the full eligibility criteria
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) and have retained at least 1 NT-501 at study entry.
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) and have retained at least 1 NT-501 at study entry.
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. 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.
3. 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.
Exclusion Criteria
To participate in this study, the potential participant must not meet any of the following criteria. (Note that the ocular exclusion criteria are relevant to the study eye\[s\], unless indicated for both eyes):
Exclusion Criteria Applicable to Arms 1, 2, and 3:
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 undergone explantation of NT-501 prior to screening. Note: A participant who received bilateral implants and underwent explantation in only 1 eye prior to screening may be enrolled in the study.
4. Participant received Encelto commercial implant in the fellow eye, if applicable, less than 3 months prior to study screening.
Exclusion Criteria Applicable to Arm 3 Only:
5. Participant has significant corneal or media opacities in the study eye to be implanted.
6. Participant has evidence of pathologic myopia in the study eye to be implanted.
7. 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.
8. 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.
9. 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).
10. Received intravitreal steroid therapy in the study eye to be implanted within 6 months prior to screening.
11. 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.
12. Evidence of central serous chorioretinopathy in the study eye to be implanted within 3 months prior to screening.
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.What this study is about
In the sponsor’s own words, from the registry.
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 and have retained at least 1 NT-501 at study entry. 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.
Study sites(26)
Scripps Health
La Jolla, California, United States
Not yet recruiting
Jules Stein Eye Institute/UCLA
Los Angeles, California, United States
Not yet recruiting
Stanford University School of Medicine
Palo Alto, California, United States
Recruiting
Bay Area Retina Associates
Walnut Creek, California, United States
Recruiting
Colorado Retina
Lakewood, Colorado, United States
Recruiting
Bascom Palmer
Miami, Florida, United States
Not yet recruiting
Emory Eye Center
Atlanta, Georgia, United States
Recruiting
Northwestern University
Chicago, Illinois, United States
Recruiting
National Eye Institute
Bethesda, Maryland, United States
Not yet recruiting
Cumberland Valley Retina Consultants
Frederick, Maryland, United States
Recruiting
Massachusetts Eye and Ear Infirmary, Retina Service
Boston, Massachusetts, United States
Not yet recruiting
Foundation for Vision Research
Grand Rapids, Michigan, United States
Recruiting
Retina Consultants of Minnesota
Minneapolis, Minnesota, United States
Not yet recruiting
Envision Ocular, LLC
Bloomfield, New Jersey, United States
Recruiting
Cincinnati Eye Institute
Cincinnati, Ohio, United States
Recruiting
Retina Associates of Cleveland, Inc.
Cleveland, Ohio, United States
Recruiting
Retina Northwest, P.C.
Portland, Oregon, United States
Recruiting
Scheie Eye Institute
Philadelphia, Pennsylvania, United States
Not yet recruiting
Southeastern Retina Associates, P.C.
Knoxville, Tennessee, United States
Recruiting
Texas Retina Associates
Dallas, Texas, United States
Recruiting
Retina Center of Texas
Dallas, Texas, United States
Recruiting
Retina Consultants of Texas
Houston, Texas, United States
Recruiting
University of Utah John A. Moran Center
Salt Lake City, Utah, United States
Recruiting
Cerulea
East Melbourne, Australia
Recruiting
Lion's Eye Institute
Perth, Australia
Recruiting
Sydney Eye Hospital
Sydney, Australia
Recruiting
Showing 26 of 26 sites. 19 of the 26 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.
Source: ClinicalTrials.gov record NCT06971939. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.
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