Dr Bowlus: Treatments for primary biliary cholangitis (PBC) are currently ursodeoxycholic acid, and recently approved in the United States and Europe, obeticholic acid. Obeticholic acid is indicated in PBC when there is an incomplete response to urso, or in patients who are unable to tolerate urso. The main benefit of obeticholic acid that has been demonstrated has been the improvement in liver biochemistry with treatment. These improvements suggest that there are long-term benefits in terms of clinical outcomes, but that remains to be demonstrated in a clinical trial. In terms of the consideration for use of obeticholic acid, the most common adverse event associated with it has been itching or pruritis. That can be relatively common in patients who have pre-existing underlying pruritis. However, at the dose that is currently recommended (5mg daily with titration to 10mg), pruritis or itching tends to be relatively well tolerated and minimal. There was a recent warning issued by the FDA in terms of use of obeticholic acid in patients with PBC where most of the concerns were associated with patients with decompensated liver disease (Child's B or C cirrhosis). For those patients, the recommended dose is 5mg weekly, then to increase slowly if tolerated. The problems have been in patients who were dosed at 5mg daily. I think strong consideration should be given to any use of obeticholic acid in those patients who have decompensated cirrhosis.
Dr Bowlus: Primary sclerosing cholangitis (PSC) remains a disease without any proven therapies. Part of the problem in developing new treatments for PSC has to do with the lack of validated biomarkers for disease progression that could be used in clinical trial development. In clinical practice, of course, we monitor liver tests and markers of portal hypertension, liver biochemistries, as well as surveillance for cholangiosarcoma, which is relatively common in these patients. There has been some work developing new biomarkers for this condition to be used in clinical trials. Some of the most promising ones involve serum markers, including the enhanced liver fibrosis (ELF) test. Imaging modalities to measure liver stiffness including vibration controlled transient elastography (FibroScan) and MR elastography have also been shown to be associated with outcomes. Then liver histology via biopsy is another good indicator of outcomes. Any number of these need to be validated further and likely will be in the future.
Dr Bowlus: For new therapies for the autoimmune diseases (typically considered to be PBC, PSC, autoimmune hepatitis and rarely IgG4-related sclerosing cholangitis), the biggest advances have obviously been made with PBC where we have obeticholic acid. There are several other drugs in clinical trials right now, including other farnesoid X receptor (FR) agonists. There have also been some recently published studies at the International Liver Congress on the use of bezafibrate in PBC, which is very promising. Other PPAR agonists are being studied as well. In PSC, there have been some recent studies with norursodeoxycholic acid, as well as obeticholic acid showing biochemical improvements. Those are promising as well. There are other therapies in clinical trials for that disease, and we look forward to some results from those studies. In terms of autoimmune hepatitis, we are doing well with our current regimen of prednisone and azathioprine, but there is still a need for new therapies in that group of patients who don’t have a good response to those drugs. There are a couple of studies in development right now, but much less has been done in that disease area.