CNTF Implants for CNGB3 Achromatopsia

Summary

Background: * 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. Objectives: * 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. Eligibility: 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. Design: * 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.

Timeline

Start

2012-07

Primary completion

2013-03

Completion

2015-10

Publications

• Background Kohl S, Baumann B, Broghammer M, Jagle H, Sieving P, Kellner U, Spegal R, Anastasi M, Zrenner E, Sharpe LT, Wissinger B. Mutations in the CNGB3 gene encoding the beta-subunit of the cone photoreceptor cGMP-gated channel are responsible for achromatopsia (ACHM3) linked to chromosome 8q21. Hum Mol Genet. 2000 Sep 1;9(14):2107-16. doi: 10.1093/hmg/9.14.2107.
• Background Wissinger B, Gamer D, Jagle H, Giorda R, Marx T, Mayer S, Tippmann S, Broghammer M, Jurklies B, Rosenberg T, Jacobson SG, Sener EC, Tatlipinar S, Hoyng CB, Castellan C, Bitoun P, Andreasson S, Rudolph G, Kellner U, Lorenz B, Wolff G, Verellen-Dumoulin C, Schwartz M, Cremers FP, Apfelstedt-Sylla E, Zrenner E, Salati R, Sharpe LT, Kohl S. CNGA3 mutations in hereditary cone photoreceptor disorders. Am J Hum Genet. 2001 Oct;69(4):722-37. doi: 10.1086/323613. Epub 2001 Aug 30.
• Background Kohl S, Baumann B, Rosenberg T, Kellner U, Lorenz B, Vadala M, Jacobson SG, Wissinger B. Mutations in the cone photoreceptor G-protein alpha-subunit gene GNAT2 in patients with achromatopsia. Am J Hum Genet. 2002 Aug;71(2):422-5. doi: 10.1086/341835. Epub 2002 Jun 20.
• Results Zein WM, Jeffrey BG, Wiley HE, Turriff AE, Tumminia SJ, Tao W, Bush RA, Marangoni D, Wen R, Wei LL, Sieving PA. CNGB3-achromatopsia clinical trial with CNTF: diminished rod pathway responses with no evidence of improvement in cone function. Invest Ophthalmol Vis Sci. 2014 Sep 9;55(10):6301-8. doi: 10.1167/iovs.14-14860.

Drugs

Indications