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Macular Telangiectasia Type 2 (MacTel)Phase 4NCT06971939

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

A Phase 4 study testing NT-501/revakinagene taroretcel-lwey in people with Macular Telangiectasia Type 2 (MacTel), run by Neurotech Pharmaceuticals at 26 sites in 2 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial summary

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… Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Macular Telangiectasia Type 2 (MacTel)
What is being tested?
NT-501/revakinagene taroretcel-lwey
Could I receive a placebo?
No, everyone receives an active treatment
How many people
234 participants
Where
26 sitesin 2 countries
Study dates
21 Nov 2025to 15 Jan 2032
Phase
Phase 4
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • To be eligible to participate in this study, an individual participant must meet all the following criteria:
  • Male or female adult participants who previously completed an NT-501 MacTel clinical study and:
  • 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.
  • 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).
  • Arm 3: underwent the sham procedure in either Phase 3 study (NTMT-03-A or NTMT-03-B)
  • 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.
  • 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.

Who cannot join

  • 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):
  • Participant is medically unable to comply with clinical study procedures or visits.
  • 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.
  • 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.
  • Participant received Encelto commercial implant in the fellow eye, if applicable, less than 3 months prior to study screening.
  • Participant has significant corneal or media opacities in the study eye to be implanted.
Show all 18Show fewer
  • Participant has evidence of pathologic myopia in the study eye to be implanted.
  • 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.
  • 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.
  • 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).
  • Received intravitreal steroid therapy in the study eye to be implanted within 6 months prior to screening.
  • 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.
  • Evidence of central serous chorioretinopathy in the study eye to be implanted within 3 months prior to screening.
  • A history of ocular herpes virus in the study eye to be implanted.
  • Participant is on chemotherapy.
  • Participant is pregnant or breastfeeding.
  • Participation in any other clinical study of an intervention (drug or device) within 6 months prior to the screening/baseline visit.
  • A history of malignancy that would compromise survival during the clinical study.

Trial locations and contacts

26 sites in 2 countries. Contact the study team or a site near you to ask about taking part.

Patricia Davis contact

401-333-3880

p.davis@neurotechusa.com

26 sites in 2 countries

United States23 sites, 23 recruiting

  • Emory Eye Center

    Atlanta, Georgia, 30322

    Donna Leef, dleef@emory.edu

    Jiong Yan, MD

    Recruiting

  • National Eye Institute

    Bethesda, Maryland, 20892

    Faith Chen, chenfa@nei.nih.gov

    Tiarnan Keenan, MD

    Not yet recruiting

  • Envision Ocular, LLC

    Bloomfield, New Jersey, 07003

    Kathleen Rodriguez, krodriguez@retinacenternj.com

    Patrick Higgins, MD

    Recruiting

  • Massachusetts Eye and Ear Infirmary, Retina Service

    Boston, Massachusetts, 02114

    Michael Cheung, mcheung@meei.harvard.edu

    Dean Eliott, MD

    Not yet recruiting

  • Northwestern University

    Chicago, Illinois, 60611

    Jessica Gacki-Smith, angela.giliana@northwestern.edu

    Ivy Zhu, MD

    Recruiting

  • Cincinnati Eye Institute

    Cincinnati, Ohio, 45242

    Kelye Conrad, kconrad@cvphealth.com

    Lucas Lindsell, MD

    Recruiting

  • Retina Associates of Cleveland, Inc.

    Cleveland, Ohio, 44126

    Diane Weiss, dew@retina-assoc.com

    Joseph Coney, MD

    Recruiting

  • Texas Retina Associates

    Dallas, Texas, 75231

    Ashley Hughes, ahughes@texasretina.com

    Ashkan Abbey, MD

    Recruiting

  • Retina Center of Texas

    Dallas, Texas, 75251

    Greg Dunn, greg.dunn@retinacentertx.com

    Jawad Qureshi, MD

    Recruiting

  • Cumberland Valley Retina Consultants

    Frederick, Maryland, 21702

    Brittany Carson, brittanyc@retinacare.net

    David Warrow, MD

    Recruiting

  • Foundation for Vision Research

    Grand Rapids, Michigan, 49525

    Holly Vincent, holly@fvr.org

    Liliya Sutherland, MD

    Recruiting

  • Retina Consultants of Texas

    Houston, Texas, 77030

    Rachel Bean, rachel.bean@retinaconsultantstexas.com

    Charles Wykoff, MD

    Recruiting

  • Southeastern Retina Associates, P.C.

    Knoxville, Tennessee, 37922

    Jeff Wheeler, jwheeler@seretina.com

    Stephen Perkins, MD

    Recruiting

  • Scripps Health

    La Jolla, California, 92037

    TBD TBD, lin.richard@scrippshealth.org

    Richard Lin, MD

    Not yet recruiting

  • Colorado Retina

    Lakewood, Colorado, 80228

    Victoria Lee, vlee@retinacolorado.com

    Murtaza Adam, MD

    Recruiting

  • Jules Stein Eye Institute/UCLA

    Los Angeles, California, 90085

    Reginald Hughes, rehughes@mednet.ucla.edu

    Colin McCannel, MD

    Not yet recruiting

  • Bascom Palmer

    Miami, Florida, 33136

    Monica Roxana Arango, MrArango@med.miami.edu

    Philip Rosenfield, MD

    Not yet recruiting

  • Retina Consultants of Minnesota

    Minneapolis, Minnesota, 55435

    Mallorie Schieck, 952-259-6264, MSchieck@RetinaMN.com

    Abdhish Bhavsar, MD

    Not yet recruiting

  • Stanford University School of Medicine

    Palo Alto, California, 94303

    Negin Yavari, nyavari@stanford.edu

    Diana Do, MD

    Recruiting

  • Scheie Eye Institute

    Philadelphia, Pennsylvania, 19104

    Devica Bhutani, devica.bhutani@pennmedicine.upenn.edu

    Alexander Brucker, MD

    Not yet recruiting

  • Retina Northwest, P.C.

    Portland, Oregon, 97221

    Mary Ann Aiken, maiken@retinanorthwest.com

    Michael Lee, MD

    Recruiting

  • University of Utah John A. Moran Center

    Salt Lake City, Utah, 84132

    Barbara Hart, barbara.hart@hsc.utah.edu

    Paul Bernstein, MD

    Recruiting

  • Bay Area Retina Associates

    Walnut Creek, California, 94598

    Grace Marudo, gmarudo@bayarearetina.com

    Roger Goldberg, MD

    Recruiting

Other trials in United States

Australia3 sites, 3 recruiting

  • Cerulea

    East Melbourne

    Thuy Chau, tchau@ceruleaclinicaltrials.org.au

    Penelope Allen, MD

    Recruiting

  • Lion's Eye Institute

    Perth

    Diana Bowman, diana.bowman@lei.org.au

    Ian Constable, MD

    Recruiting

  • Sydney Eye Hospital

    Sydney

    Emily Luu, emily.luu@sydney.edu.au

    Elisa Cornish, MD

    Recruiting

Other trials in Australia

About this study

Official title: 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)

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.

Read the detailed description

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) and have retained at least 1 NT-501at study entry.
  • 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) and have retained at least 1 NT-501 at study entry.
  • 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. For participants who previously received a single NT-501 implant, the implanted eye is designated the study eye. For participants who received an NT-501 in both eyes (ie, the first implant received in NTMT-01, NTMT-02, NTMT-01/02E, NTMT-03A, or NTMT-03B, and the second implant received in NTMT-02B), both eyes will be designated as study eyes.

Only participants in Arm 3 will receive active intervention during this Phase 4 study. A participant can receive NT-501 in either eye that meets eligibility criteria according to investigator assessment, and in accordance with participant choice. However, if only 1 eye is eligible for implantation based on all inclusion/exclusion criteria, then that eye will be selected for NT-501 implantation. The eye selected for NT-501 implantation will be designated as the study eye.

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

Being tested
NT-501/revakinagene taroretcel-lwey
Keywords
Ciliary Neurotrophic Factor (CNTF), Macular Telangiectasia Type 2 (MacTel)

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • NT-501/revakinagene taroretcel-lweyCombination product

    Also called ENCELTO

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

Study groups in NCT06971939
Study groupRoleWhat they receive
Arm 1 (Phase 3 Long-term Follow-up)OtherFor 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 1 is focused on long term follow-up for participant who already has the ENCELTO implant at time of study screening and enrollment.
Receives: Combination Product: NT-501/revakinagene taroretcel-lwey
Arm 2 (Phase 1 and Phase 2 Long-term Follow-up)OtherFor 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.
Receives: Combination Product: NT-501/revakinagene taroretcel-lwey
Arm 3 (Phase 3 Sham to Implant Crossover)ExperimentalFor 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.
Receives: Combination Product: NT-501/revakinagene taroretcel-lwey

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of ocular and nonocular adverse events (AEs) and serious adverse events (SAEs)

    Incidence of ocular and nonocular adverse events (AEs) and serious adverse events (SAEs)

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

  2. Percentage of participants with a loss of 15 letters or more in best corrected visual acuity (BCVA) compared to presurgery baseline BCVA

    Percentage of participants with a loss of 15 letters or more in best corrected visual acuity (BCVA) compared to presurgery baseline BCVA using the Early Treatment Diabetic Retinopathy Study (ETDRS) distance chart

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

Secondary outcomes (5)

  1. Change from presurgery baseline in ellipsoid zone (EZ) area loss

    Change from presurgery baseline in ellipsoid zone (EZ) area loss as measured by en face spectral domain optical coherence tomography (SD-OCT) for both eyes

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

  2. Change from presurgery baseline in BCVA

    Change from presurgery baseline in BCVA using the ETDRS distance chart for both eyes

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

  3. Change from presurgery baseline in aggregate retinal sensitivity

    Change from presurgery baseline in aggregate retinal sensitivity as measured by microperimetry within the EZ line break area for both eyes

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

  4. Change from presurgery baseline in monocular reading speed

    Change from presurgery baseline in monocular reading speed for both eyes

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

  5. Change from presurgery baseline in the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25)

    Change from presurgery baseline in NEI-VFQ-25 near activities subscale score. All items are scored so that a high score represents better functioning. Each item is then converted to a 0 to 100 scale so that the lowest and highest possible scores are set at 0 and 100 points, respectively.

    Measured: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 May 2025
  2. Study start21 Nov 2025
  3. Primary completion15 Jan 2032 (estimated)
  4. Study completion15 Jan 2032 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 4
Primary purpose
Treatment
Allocation
Non-randomised
Intervention model
Parallel groups
Model description
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.
Masking
None (open label)
Enrolment
234 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06971939
Sponsor's protocol ID
NTMT-04
Status last verified
Sep 2026
First submitted
29 Apr 2025
Last updated
25 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
Yes
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 4 study testing NT-501/revakinagene taroretcel-lwey in people with Macular Telangiectasia Type 2 (MacTel), run by Neurotech Pharmaceuticals at 26 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 8 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 25 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 26 sites in United States, Australia. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Patricia Davis (401-333-3880, p.davis@neurotechusa.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of ocular and nonocular adverse events (AEs) and serious adverse events (SAEs) (time frame: Baseline and annually for up to 5 yrs for Arms 1 and 2 and baseline, perioperative, and annually for up to 5 yrs for Arm 3 participants). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06971939.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Sep 2026.

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