A Study of Encapsulated Cell Technology (ECT) Implant for Participants With Early Stage Retinitis Pigmentosa

Phase 2

Completed

Brief 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.

Detailed Description: This study will involve about 18 visits over 2½ years for specific tests of the participant's vision and health. These visits may include visual exams, blood draw for laboratory testing, brief medical history and exam, and occasionally a questionnaire (survey), in addition to the visit for the surgical procedures. The primary effectiveness outcome for this study will be a visual field score one year after the implant surgery. There will be about 12 centers participating in this study, and up to 60 people enrolled, across the US. Each participant joining the study who has completed initial screening will then be scheduled to have a brief surgical procedure performed on each eye, one of which will include a very small cell-filled implant. Follow-up visits for repeat assessments will be required regularly to determine if the implant being tested is safe and effective for use to treat retinitis pigmentosa (RP).

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
High Dose	NT-501	NT-501 High Dose Implant: encapsulated cell therapy that delivers ciliary neurotrophic factor to the retina Sham Implant in Fellow Eye
Low Dose	NT-501	NT-501 Low Dose Implant: encapsulated cell therapy that delivers ciliary neurotrophic factor to the retina Sham Implant in Fellow Eye

Primary Outcome Measures

Name	Time	Method
Change in Humphrey Visual Fields - Total Sensitivity	12 months	The primary efficacy endpoint was the change in Humphrey VFS from baseline to month 12 (Visit 10) as determined by the HVF 30-2 test, comprised of 76 points. The measure was the sum of actual thresholds for all 76 locations.

Secondary Outcome Measures

Name	Time	Method
Change in Mean Humphrey Visual Fields Sensitivity	Baseline compared to 6, 12, 18, 24 and 30 months
Mean Humphrey Visual Fields Sensitivity	Baseline compared to 6, 12, 18, 24 and 30 months	Change in Humphrey Visual Field Sensitivity over time

Locations (12): The Hamilton Eye Institute
🇺🇸
Memphis, Tennessee, United States
Retina Foundation of Southwest
🇺🇸
Dallas, Texas, United States
The University of Utah - John A. Moran Eye Center
🇺🇸
Salt Lake City, Utah, United States
Retina-Vitreous Associates Medical Group
🇺🇸
Beverly Hills, California, United States
University of Califoria, Davis
🇺🇸
Sacramento, California, United States
University of California, San Francisco
🇺🇸
San Francisco, California, United States
Bascom Palmer Eye Insitute
🇺🇸
Miami, Florida, United States
Kellogg Eye Center
🇺🇸
Ann Arbor, Michigan, United States
University of Minnesota
🇺🇸
Minneapolis, Minnesota, United States
NY University Medical Center
🇺🇸
New York, New York, United States
Casey Eye Institue
🇺🇸
Portland, Oregon, United States
University of Utah
🇺🇸
Salt Lake City, Utah, United States