NCT06971939 · Neurotech Pharmaceuticals
Phase 4 Study: Long-term Safety and Efficacy of NT-501 in MacTel Type 2, Including Sham Procedure Participants
What this study is about
The purpose of this global, conducted at multiple hospitals, where both patients and doctors know the treatment given, Phase 4 clinical extension study is to evaluate the long-term safety and effectiveness 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 effectiveness of NT501 in participants who previously underwent the sham procedu
View original scientific description
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.
Interventions
COMBINATION_PRODUCT
NT-501/revakinagene taroretcel-lwey
NT-501 is surgically implanted into the vitreous cavity to continuously release recombinant human ciliary neurotrophic factor (CNTF).
Primary outcome measures
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
Incidence of ocular and nonocular adverse events (AEs) and serious adverse events (SAEs)
Percentage of participants with a loss of 15 letters or more in best corrected visual acuity (BCVA) compared to presurgery baseline BCVA
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
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
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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.
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:
- 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. Exclusion Criteria Applicable to Arm 3 Only:
- 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 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.
Where
- La Jolla, California
- Los Angeles, California
- Palo Alto, California
- Walnut Creek, California
- Lakewood, Colorado
- Miami, Florida
- Atlanta, Georgia
- Chicago, Illinois
- Bethesda, Maryland
- Frederick, Maryland
- Boston, Massachusetts
- Grand Rapids, Michigan
And 10 more locations — see the full list below.
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 25, 2026 · Source of record for eligibility and locations