Medical Need and Market Opportunity
CLF involves the progressive destruction of liver cells over time resulting in fibrosis and cirrhosis. The cause of the chronic decompensation or liver failure may vary and, similar to ACLF, includes infections, such as subacute bacterial peritonitis, HCV or HBV, metabolic causes, such as NASH, autoimmune diseases and alcohol. Eventually, these patients will progress to the point where, if eligible, they may require transplantation. The difference between this population and ACLF is that in ACLF, patients have an acute event that triggers a decompensatory event that may be reversed whereas in CLF, the event is of a chronic nature and it is unlikely that the liver function will improve. Objectives for the management of patients with CLF will be either to ensure that they stabilize to the point that they are eligible for transplant or that they survive until the time of transplant. The same therapies as those employed for the management of ACLF and mentioned above are generally employed. In CLF, apoptosis is elevated as determined by serological biomarkers and histology, which correlates with clinical worsening. Independent published studies have shown that cCK18 levels are elevated in CLF patients and correlate with extent of liver inflammation and cholestasis.
Although we are not planning to exclusively study patients with CLF on the liver transplant waitlist, many of these patients may also be included in the study. According to the U.S. Department of Health and Human Services, there were over 5,800 adult liver transplants performed in the United States in 2011 and approximately 2,500 died while waiting for transplant and another 500 subsequently became ineligible for a liver transplant. We estimate that there are approximately 5,000 CLF patients in our target population on the transplant waitlist in the United States and the EU. The median wait time for a liver transplant for the subset of patients with MELD scores of 19-24 is 106 days and the mortality rate is approximately 25% during that time frame, according to the United Network for Organ Sharing database. We estimate that there will be at least the same number of patients with CLF who are not candidates for liver transplantation but who might also benefit from emricasan. Given its mechanism of action, emricasan has the potential to improve patients’ ability to survive longer while waiting for a liver transplant or potentially make them eligible for transplant.