CNTF Implants for CNGB3 Achromatopsia (CNTF-CNGB3-1)
- Achromatopsia is an inherited condition that causes vision loss because cells in the retina do not work properly. It causes loss of acuity, sensitivity to light, and loss of color vision. There are no effective treatments for achromatopsia.
- Four genes currently are known to cause achromatopsia. One of these, the cyclic nucleotide-gated channel beta 3 (CNGB3) gene, is the cause in about 50 percent of people.
- CNTF is a natural chemical found in the body that promotes survival and function of nerve cells. CNTF has been shown to be effective in treating retinal disease in animals and can slow vision loss.
- CNTF has also been studied in over 250 people with retinal disease other than achromatopsia. In these studies, a CNTF implant was placed into the eye during a simple surgery. The implant releases CNTF inside the eye, near the retina. These studies suggested that a CNTF implant might help vision in some eye diseases.
- To learn whether a CNTF implant is safe for people with CNGB3 achromatopsia.
- To learn whether CNTF can improve visual acuity or color vision, and whether it may reduce sensitivity to light in people with CNGB3 achromatopsia.
You may be able to take part in this study if you:
- Are at least 18 years old.
- Test positive for mutations in the CNGB3 gene and have no mutations in another achromatopsia gene.
- Have 20/100 vision or worse in at least one eye.
- Are not pregnant or nursing.
- To determine if you can take part, we will ask about your medical history and do a physical examination and an eye examination. Blood and urine samples will be taken.
- This study requires 11 visits to the National Eye Institute over 3 years.
- One visit will be for the implant surgery. The implant will be placed in one eye only.
- Study visits will take place 1 day after implant surgery, and again 1 week later and 1 month, 3 months, 6 months, 1 year, 1.5 years and 3 years later. These visits will help us evaluate the safety and benefit of the implant on your eye.
- At the 3 year visit, you can choose to keep the CNTF implant in your eye, or you can have us remove it.
Biological: NT-501 CNTF-releasing implant
|Study Design:||Endpoint Classification: Safety Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||A Phase I/II Study of the NT-501 Intraocular Implant Releasing Ciliary Neurotrophic Factor (CNTF) in Participants With CNGB3 Achromatopsia|
- Number of Adverse Events [ Time Frame: 6 months (24 weeks) post-implantation ] [ Designated as safety issue: Yes ]The number of all adverse events at six months post-implantation was calculated.
- Number of Severe Adverse Events [ Time Frame: 6 months (24 weeks) post-implantation ] [ Designated as safety issue: Yes ]The number of severe adverse events at six months post-implantation was calculated.
- Number of Ocular Adverse Events [ Time Frame: 6 months (24 weeks) post-implantation ] [ Designated as safety issue: Yes ]The number of eye-related adverse events at six months post-implantation was calculated.
- Number of Non-Ocular Adverse Events [ Time Frame: 6 months (24 weeks) post-implantation ] [ Designated as safety issue: Yes ]The number of adverse events that were not eye-related at six months post-implantation was calculated.
- Additional Safety of Ocular CNTF Implants in Participants With CNGB3 Achromatopsia Will be Determined From Assessment of Retinal Function, Ocular Structure and Occurrence of Adverse Events. [ Time Frame: All Time Points Post-Implantation (1 Day, 1 Week, 4 Weeks, 12 Weeks, 24 Weeks, 1 year, 1.5 years and 3 years) ] [ Designated as safety issue: Yes ]
- Secondary Outcomes Include Changes in Visual Function Including Visual Acuity and Color Vision, Electroretinogram (ERG) Response, and Retinal Imaging With Optical Coherence Tomography (OCT). [ Time Frame: All Time Points Post-Implantation (1 Day, 1 Week, 4 Weeks, 12 Weeks, 24 Weeks, 1 year, 1.5 years and 3 years) ] [ Designated as safety issue: No ]
|Study Start Date:||July 2012|
|Estimated Study Completion Date:||October 2015|
|Primary Completion Date:||March 2013 (Final data collection date for primary outcome measure)|
Experimental: NT-501 CNTF-releasing implant
Ocular implantation of a NT-501 CNTF-releasing capsule (20 ng/day) in one eye (the study eye) at baseline
Biological: NT-501 CNTF-releasing implant
20 ng/day released into the eye
Objective: The objective of this study is to evaluate the safety of ocular NT-501 device with encapsulated NT-201 cells releasing Ciliary Neurotrophic Factor (CNTF) to the retina of participants affected with CNGB3 achromatopsia.
Study Population: Five participants affected with CNGB3 achromatopsia will be enrolled, with one eye treated per participant.
Design: This is a Phase I/II, prospective, single-center study. One eye of each participant will receive a vitreous NT-501 device implant releasing CNTF. The study will be completed once the final participant has received three years of follow-up.
Outcome Measures: The primary outcome is the number and severity of adverse events and systemic and ocular toxicities at six months post-implantation. Additional safety of ocular CNTF implants in participants with CNGB3 achromatopsia will be determined from assessment of retinal function, ocular structure and occurrence of adverse events at all time points. Secondary outcomes include changes in visual function including visual acuity and color vision, electroretinogram (ERG) responses, and retinal imaging with optical coherence tomography (OCT).
Please refer to this study by its ClinicalTrials.gov identifier: NCT01648452
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|
|Principal Investigator:||Paul A Sieving, MD, PhD||National Eye Institute (NEI)|