Clinical Research Studies

PSC is a chronic disease which causes scarring of the bile ducts. When the bile ducts are damaged, the ducts become hard and narrow and this can block the flow of bile which can cause damage to the liver over time. This study will test an experimental drug named GS-9674 for the treatment of primary sclerosing cholangitis (PSC). An experimental drug is one that has not been approved by the Food and Drug Administration (FDA) for sale in the United States or by any regulatory authorities in any country in the world. Experimental drugs like GS-9674 may be tested in research studies such as this one. While PSC can be without symptoms, especially early in the disease, some symptoms of PSC can include fatigue (feeling tired), itching, and jaundice (yellowing of eyes and skin). The symptoms of PSC are related to the blockage of bile flow from the scarred bile ducts and a build-up of bile acids. Patients with PSC can develop cirrhosis (severe scarring of the liver) that can lead to liver failure. PSC is also a major risk factor for the development of cancer of the bile ducts (cholangiocarcinoma). The only effective treatment for PSC is liver transplantation (removing the damaged liver and replacing it with a healthy one from a donor). GS-9674 is being developed to reduce bile acids because elevated bile acids contribute to symptoms of PSC including inflammation and fibrosis in the liver. The purpose of this study is to see if GS-9674 slows the scarring process in subjects with PSC.