Phase 2
N=146
A Study of Encapsulated Cell Technology (ECT) Implant for Participants With Early Stage Retinitis Pigmentosa
Retinitis Pigmentosa
Bottom Line
View on ClinicalTrials.gov: NCT00447980 ↗Enrolled (actual)
146
Serious AEs
7.4%
Results posted
May 2025
Primary outcome: Primary: Change in Humphrey Visual Fields - Total Sensitivity — 1.4; 16.8; -164.8; -66.7 dB
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 2
- Interventions
- NT-501 (Drug)
- Age
- Adult · 18+ yrs
- Sex
- All
- Sponsor
- Neurotech Pharmaceuticals
- Primary completion
- Apr 2010
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Change in Humphrey Visual Fields - Total Sensitivity |
1.4; 16.8; -164.8; -66.7 | — |
| SECONDARY Change in Mean Humphrey Visual Fields Sensitivity |
-1.21; 25.80; -135.23; -42.99; 1.35; 16.75 | — |
| SECONDARY Mean Humphrey Visual Fields Sensitivity |
1142.43; 1135.94; 969.83; 961.70; 1141.21; 1161.74 | — |
Summary
The purpose of this study is to look at the safety and effectiveness of CNTF implants on vision in persons with retinitis pigmentosa, Usher type II & III, and Choroideremia. This research is being done because there are no effective therapies for people with these retinal degenerations. They are genetic disorders that affect one's ability to see at night, and later cause tunnel vision and loss of central vision. Retinal degenerations affect the retina, a light sensitive layer of cells in the back of the eye. Slowly over time, these cells die and cause permanent loss of vision.
The implant is a small capsule that contains human retinal pigment epithelium cells. These cells have been given the ability to make CNTF and release it through the capsule membrane into the surrounding fluid. In this study, two different CNTF dose levels will be used: a high dose and a low dose in one eye, as well as a sham (or placebo) surgery in the other eye.
Eligibility Criteria
Study inclusion / exclusion criteria:
Criteria for patients to qualify for the study include, but are not limited to:
- Over 18 years of age, and less than 65 years of age
- Diagnosis of retinitis pigmentosa, Usher Syndrome Type 2 or 3 or Choroideremia
- Visual acuity no worse than 20/63
- Experience with at least two full threshold Humphrey Visual Field 30-2 tests, one completed within the year prior to enrolling in this study
The following criteria will exclude patients from the study:
- Pregnant or lactating females, or females planning to become pregnant during the study or not using an acceptable method of contraception.
- Retinitis pigmentosa caused by a classic syndrome, including Usher Type I
- Other eye diseases including advanced cataract.
- Chronic systemic disease requiring continuous treatment with systemic steroids, immunosuppressive medications or insulin.
Data sourced from ClinicalTrials.gov (NCT00447980). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.