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

This study has been completed.
Information provided by (Responsible Party):
Neurotech Pharmaceuticals Identifier:
First received: March 9, 2007
Last updated: November 15, 2016
Last verified: November 2016

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.

Condition Intervention Phase
Retinitis Pigmentosa
Drug: NT-501
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Phase II/III Study of Encapsulated Human NTC-201 Cell Implants Releasing Ciliary Neurotrophic Factor (CNTF) for Participants With Retinitis Pigmentosa Using Visual Field Sensitivity as the Primary Outcome

Resource links provided by NLM:

Further study details as provided by Neurotech Pharmaceuticals:

Primary Outcome Measures:
  • Change in Humphrey visual field sensitivity from baseline to month 12. [ Time Frame: 12 months ]

Secondary Outcome Measures:
  • Change in visual field sensitivity [ Time Frame: 24 months ]
  • Mean, median and distribution of change in Best Corrected Visual Acuity [ Time Frame: 12 to 24 months ]
  • Change in ERG [ Time Frame: 12 to 24 months ]
  • Change in OCT [ Time Frame: 12 to 24 months ]
  • Change in inflammation [ Time Frame: 12 to 24 months ]
  • Change in vision-related quality of life [ Time Frame: 12 to 24 months ]

Enrollment: 68
Study Start Date: January 2007
Study Completion Date: July 2010
Primary Completion Date: July 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1 NT-501 implant
High Dose
Drug: NT-501
High Dose
Other Name: CNTF implant
Experimental: 2 NT-501 implant
Low Dose
Drug: NT-501
Low Dose
Other Name: CNTF implant

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).

Ages Eligible for Study:   18 Years to 64 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00447980

United States, California
Retina-Vitreous Associates Medical Group
Beverly Hills, California, United States, 90211
University of Califoria, Davis
Sacramento, California, United States, 95817
University of California, San Francisco
San Francisco, California, United States, 94143-0730
United States, Florida
Bascom Palmer Eye Insitute
Miami, Florida, United States, 33101
United States, Massachusetts
Ophthalmic Consultants of Boston
Boston, Massachusetts, United States, 02114
United States, Michigan
Kellogg Eye Center
Ann Arbor, Michigan, United States, 48105
United States, Minnesota
University of Minnesota
Minneapolis, Minnesota, United States, 55455-0501
United States, New York
NY University Medical Center
New York, New York, United States, 10016
United States, Oregon
Casey Eye Institue
Portland, Oregon, United States, 97239-4197
United States, Tennessee
The Hamilton Eye Institute
Memphis, Tennessee, United States, 38163
United States, Texas
Retina Foundation of Southwest
Dallas, Texas, United States, 75231
United States, Utah
University of Utah
Salt Lake City, Utah, United States, 84112
Sponsors and Collaborators
Neurotech Pharmaceuticals
Study Director: Weng Tao, MD, PhD Neurotech Pharmaceuticals
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Neurotech Pharmaceuticals Identifier: NCT00447980     History of Changes
Other Study ID Numbers: CNTF 4
Study First Received: March 9, 2007
Last Updated: November 15, 2016

Keywords provided by Neurotech Pharmaceuticals:
Retinitis Pigmentosa
eye disease
retinal disorder

Additional relevant MeSH terms:
Retinitis Pigmentosa
Retinal Diseases
Eye Diseases
Eye Diseases, Hereditary
Retinal Dystrophies
Retinal Degeneration
Genetic Diseases, Inborn processed this record on April 28, 2017