The liver is the largest internal organ in the human body and its proper function is indispensable for many critical metabolic functions, including the regulation of lipid and sugar metabolism, the production of important proteins, including those involved in blood clotting, and purification of blood. There are over 100 described diseases of the liver, and because of its many functions, these can be highly debilitating and life-threatening unless effectively treated. Common causes of liver disease include viral infections, such as HCV and HBV, obesity, chronic excessive alcohol use or autoimmune diseases. Many people with active liver disease remain undiagnosed largely because liver disease patients are often asymptomatic for many years. The NIH estimates that 5.5 million Americans have chronic liver disease or cirrhosis, and liver disease is the twelfth leading cause of death in the United States. According to the EASL, 29 million Europeans have chronic liver disease and liver disease represents approximately two percent of deaths annually.
Liver disease is often first detected as active hepatitis, which is defined as inflammation of the liver. Hepatitis is easily detected by a routine laboratory test to measure blood levels of the liver enzyme ALT. ALT is elevated in almost all liver diseases and represents an overall measure of liver inflammation and liver cell death. As liver disease progresses, fibrotic scar tissue will begin to replace healthy liver tissue and over time will reduce the liver’s ability to function properly. A liver biopsy is used to diagnose fibrosis and determine how much liver scarring has developed. If fibrosis is allowed to progress, it will lead to cirrhosis. As liver cirrhosis becomes progressively worse, all aspects of liver function will dramatically decline.
Some patients with liver cirrhosis have a partially functioning liver, which is referred to as compensated liver disease, and may appear asymptomatic for long periods of time. When the liver is unable to perform its normal functions this is referred to as decompensated liver disease. ACLF occurs in patients who are in relatively stable condition until an acute event sets off a rapid deterioration of liver function. The morbidity and mortality of the patient population with ACLF we plan to study is high, with approximately 45% of patients dying or progressing to multi-organ failure or requiring transplant within 28 days of hospitalization as a result of the acute decompensating episode. If the patient survives the acute decompensating event, they may return to a stable state. Patients with CLF suffer from continual disease progression which may eventually lead them to require liver transplantation. Despite advances in liver transplantation, morbidity and mortality in the CLF patient population remains high with some patients ineligible for a liver transplant and others unable to be matched with a suitable donor liver.
Patients who receive liver transplants as a result of HCV infection are at risk of accelerated fibrosis of the transplanted liver. This occurs because residual HCV is still present in the patient’s blood and can immediately infect the new liver , thus increasing the risk of accelerated inflammation and fibrosis. This patient population is referred to as HCV-POLT. Liver fibrosis can be scored using the standard Ishak Fibrosis Score, which stages the severity of fibrosis and/or cirrhosis on a 0-6 scale. Approximately 55% of the patient population we plan to study will progress more than one stage in fibrosis score within two years of transplant and 50% of these HCV-POLT patients will have stage 3 fibrosis within five years after their transplants. If emricasan demonstrates the ability to halt the progression of fibrosis in the HCV-POLT population, we believe that this could serve as a basis to evaluate emricasan for additional indications in patients at earlier stages of liver fibrosis resulting from HCV, HBV, obesity, chronic excessive alcohol use or autoimmune diseases.
Resources
Additional Information about your liver and liver disease can be found at the links below:
American Liver Foundation
http://www.liverfoundation.org/
National Digestive Diseases Information Clearinghouse
http://digestive.niddk.nih.gov/ddiseases/topics/liver.asp
Directory of Digestive Disease Organizations for Patients
http://digestive.niddk.nih.gov/resources/organizations.htm