Many patients with scleroderma have damage to their kidneys caused by the disease. There is
limited evidence for treatments to prevent this damage or stop it progressing. Blocking a
substance in the blood called endothelin has helped treat some aspects of scleroderma. The
purpose of this study is to see how effective a new endothelin blocker called Zibotentan is
in treating patients who have scleroderma and have gone on to develop reduced kidney function
as a complication. It will be given in addition to the accepted treatments used for
scleroderma. There will be three parts to this study each for a different group of patients:
- ZEBRA 1 for patients with mild or moderate kidney disease caused by scleroderma
- ZEBRA 2A for patients with a more severe, acute form of kidney disease caused by
scleroderma (scleroderma renal crisis) who do not require dialysis
- ZEBRA 2B for patients who have had scleroderma renal crisis and are on dialysis