Cysteamine Eye Drops to Treat Corneal Crystals in Cystinosis

Summary

Cystinosis is an inherited disease that results in poor growth and kidney disease, among other things. The damage to the kidneys and other organs is thought to be due to accumulation of cystine inside the cells of various body tissues. This chemical also accumulates in the cornea-the covering of the eye over the pupil and iris. After 10 to 20 years, the corneas of some patients become so packed with crystals that the surfaces may become irregular, occasionally causing small, painful breaks. Patients enrolled in a NIH study on cystinosis are receiving the drug cysteamine. Taken by mouth, this drug reduces cystine in some tissues, but not in the cornea. This study began in 1986 to test whether cysteamine eye drops could prevent or reduce corneal cystine crystals in these patients. The drops have been very effective in removing crystals and reducing pain in patients who take the medication as directed. Patients who do not take the medication as prescribed do not benefit. After the effectiveness of the drops was proven, the main purpose was modified to continue to evaluate the long-term safety and effectiveness of cysteamine eye drops for treating cystine crystals in the corneas of patients with cystinosis until the drops are approved by the Food and Drug Administration (FDA). When the New Drug Application (NDA) for the Sigma-Tau standard formulation is granted, this protocol will be terminated.

Timeline

Start

1986-04

Primary completion

2013-07

Completion

2013-07

Publications

• Background Kaiser-Kupfer MI, Fujikawa L, Kuwabara T, Jain S, Gahl WA. Removal of corneal crystals by topical cysteamine in nephropathic cystinosis. N Engl J Med. 1987 Mar 26;316(13):775-9. doi: 10.1056/NEJM198703263161304.
• Background Kaiser-Kupfer MI, Gazzo MA, Datiles MB, Caruso RC, Kuehl EM, Gahl WA. A randomized placebo-controlled trial of cysteamine eye drops in nephropathic cystinosis. Arch Ophthalmol. 1990 May;108(5):689-93. doi: 10.1001/archopht.1990.01070070075038.
• Background Gahl WA. Cystinosis coming of age. Adv Pediatr. 1986;33:95-126. No abstract available.
• Background Gahl WA, Kuehl EM, Iwata F, Lindblad A, Kaiser-Kupfer MI. Corneal crystals in nephropathic cystinosis: natural history and treatment with cysteamine eyedrops. Mol Genet Metab. 2000 Sep-Oct;71(1-2):100-20. doi: 10.1006/mgme.2000.3062.
• Background Iwata F, Kuehl EM, Reed GF, McCain LM, Gahl WA, Kaiser-Kupfer MI. A randomized clinical trial of topical cysteamine disulfide (cystamine) versus free thiol (cysteamine) in the treatment of corneal cystine crystals in cystinosis. Mol Genet Metab. 1998 Aug;64(4):237-42. doi: 10.1006/mgme.1998.2725.

Drugs

Indications