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

NCT06971939 | Recruiting Phase 4 DMC FDA Drug FDA Device

• 1 other identifier: NTMT-04
• Study Type: interventional
• Target: 285
• Locations: 5 countries
• Sites: 33

Brief 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 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.

Conditions

Macular Telangiectasia Type 2 (MacTel)

Keywords

Ciliary Neurotrophic Factor (CNTF); Macular Telangiectasia Type 2 (MacTel)

Outcome Measures

Primary Outcomes (2)

• 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)

  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

• 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

  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)

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

  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

• Change from presurgery baseline in BCVA

  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

• Change from presurgery baseline in aggregate retinal sensitivity

  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

• Change from presurgery baseline in monocular reading speed

  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

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

  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

Study Arms (3)

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

OTHER

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.

Combination Product: NT-501/revakinagene taroretcel-lwey

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

OTHER

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.

Combination Product: NT-501/revakinagene taroretcel-lwey

Arm 3 (Phase 3 Sham to Implant Crossover)

EXPERIMENTAL

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.

Combination Product: NT-501/revakinagene taroretcel-lwey

Interventions

NT-501/revakinagene taroretcel-lwey COMBINATION_PRODUCT

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

Also known as: ENCELTO

Arm 1 (Phase 3 Long-term Follow-up); Arm 2 (Phase 1 and Phase 2 Long-term Follow-up); Arm 3 (Phase 3 Sham to Implant Crossover)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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)
• 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).
• Arm 3: underwent the sham procedure in either Phase 3 study (NTMT-03-A or NTMT-03-B)
• Participants must have steady fixation in the foveal or parafoveal area and sufficiently clear media for good quality retinal imaging.
• 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.
• Note: Participants enrolled at investigator sites in France or Germany must agree to use 2 forms of contraception listed above during study participation.

You may not qualify if:

• 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 significant corneal or media opacities in the study eye to be implanted.
• 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 the last year.
• Received intravitreal anti-vascular endothelial growth factor therapy in the study eye to be implanted within the last 6 months.
• 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.
• Participant underwent vitrectomy, penetrating keratoplasty, trabeculectomy, or trabeculoplasty in the study eye to be implanted.
• A history of ocular herpes virus in the study eye to be implanted.
• Participant is on chemotherapy.
• Participant is pregnant or breastfeeding.

Sponsors & Collaborators

• Neurotech Pharmaceuticals: lead

Study Sites (33)

Scripps Health

La Jolla, California, 92037, United States

NOT YET RECRUITING

Jules Stein Eye Institute/UCLA

Los Angeles, California, 90085, United States

NOT YET RECRUITING

Stanford University School of Medicine

Palo Alto, California, 94303, United States

NOT YET RECRUITING

Bay Area Retina Associates

Walnut Creek, California, 94598, United States

RECRUITING

Colorado Retina

Lakewood, Colorado, 80228, United States

RECRUITING

Bascom Palmer

Miami, Florida, 33136, United States

NOT YET RECRUITING

Emory Eye Center

Atlanta, Georgia, 30322, United States

RECRUITING

Northwestern University

Chicago, Illinois, 60611, United States

NOT YET RECRUITING

National Eye Institute

Bethesda, Maryland, 20892, United States

NOT YET RECRUITING

Cumberland Valley Retina Consultants

Frederick, Maryland, 21702, United States

NOT YET RECRUITING

Massachusetts Eye and Ear Infirmary, Retina Service

Boston, Massachusetts, 02114, United States

NOT YET RECRUITING

Foundation for Vision Research

Grand Rapids, Michigan, 49525, United States

RECRUITING

Retina Consultants of Minnesota

Minneapolis, Minnesota, 55435, United States

NOT YET RECRUITING

Envision Ocular, LLC

Bloomfield, New Jersey, 07003, United States

RECRUITING

Cincinnati Eye Institute

Cincinnati, Ohio, 45242, United States

RECRUITING

Retina Associates of Cleveland, Inc.

Cleveland, Ohio, 44126, United States

RECRUITING

Tulsa Retina Consultants

Tulsa, Oklahoma, 74132, United States

NOT YET RECRUITING

Retina Northwest, P.C.

Portland, Oregon, 97221, United States

NOT YET RECRUITING

Scheie Eye Institute

Philadelphia, Pennsylvania, 19104, United States

NOT YET RECRUITING

Southeastern Retina Associates, P.C.

Knoxville, Tennessee, 37922, United States

RECRUITING

Texas Retina Associates

Dallas, Texas, 75231, United States

NOT YET RECRUITING

Retina Center of Texas

Dallas, Texas, 75251, United States

RECRUITING

Retina Consultants of Texas

Houston, Texas, 77030, United States

RECRUITING

University of Utah John A. Moran Center

Salt Lake City, Utah, 84132, United States

RECRUITING

Cerulea

East Melbourne, Australia

RECRUITING

Lion's Eye Institute

Perth, Australia

RECRUITING

Sydney Eye Hospital

Sydney, Australia

RECRUITING

Lariboisiére Hospital

Paris, France

NOT YET RECRUITING

University Eye Hospital Bonn

Bonn, Germany

NOT YET RECRUITING

UNIVERSITÄTSKLINIKUM FREIBURG, Klinik für Augenheilkunde

Freiburg im Breisgau, Germany

NOT YET RECRUITING

Augenzentrum am St. Franziskus-Hospital

Münster, Germany

NOT YET RECRUITING

Moorefield Hospital

London, United Kingdom

NOT YET RECRUITING

Oxford University Hospitals NHS FT

Oxford, United Kingdom

NOT YET RECRUITING

Study Officials

• Thomas Aaberg, Jr, MD

  Neurotech Pharmaceuticals

  STUDY CHAIR

Central Study Contacts

Patricia Davis

CONTACT

401-333-3880; p.davis@neurotechusa.com

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: 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.

Study Record Dates

• First Submitted: April 29, 2025
• First Posted: May 14, 2025
• Study Start: November 21, 2025
• Primary Completion (Estimated): January 15, 2032
• Study Completion (Estimated): January 15, 2032
• Last Updated: April 29, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

US (24); DE (3); GB (2); FR (1); AU (3)