Nonalcoholic fatty liver disease (NAFLD) is the accumulation of fat or lipids in the liver in the absence of significant alcohol uptake or viral infection. Within NAFLD there is a spectrum of disease ranging from excess storage of fat in the liver (NAFL) to fat plus inflammation (called nonalcoholic steatohepatitis or NASH), to liver fibrosis and cirrhosis, or end stage liver disease with loss of liver function. NASH is the most common cause of liver disease in developed countries, largely due to the increased prevalence of obesity and type 2 diabetes. A percentage of patients with NASH and liver fibrosis will progress to liver failure or hepatocellular carcinoma or liver cancer. In fact, NASH is expected to be the number one cause for liver transplantation in a few years, making it critical to identify high-risk patients early. Continue reading
Q&A with Claudia Filozof, MD, PhD, Senior Medical Director in the Phase II-IV Cardiovascular/Metabolic Group and Richard Williams, PhD, JD, Executive Strategist, Global Regulatory Affairs
Is this a good time to develop a NASH drug, and if so, why?
Claudia: Yes, it’s a very good time. There are multiple companies starting NASH development, and there is a huge unmet medical need with no treatment approved so far. Health authorities also have shown a lot of interest in supporting companies to speed up development. If you have the right compound, there are multiple advantages to starting a NASH program.
Richard: The cost to society will be enormous if we can’t treat this disease. I think most pharmaceutical companies, big and small, see this as a substantial unmet medical need. With this unmet medical need, regulatory agencies can grant conditional approval (accelerated approval in the US), where the drug is approved for marketing with the condition that the company later shows it has a clinical benefit based on clinical outcomes. Continue reading
Non-alcoholic steatohepatitis (NASH) can lead to serious conditions such as cirrhosis and its complications, liver cancer and hepatic transplantation. Many patients eventually die from liver-related problems or cardiovascular disease. The challenge in developing drugs for NASH is to demonstrate an improvement in clinical outcomes. Cirrhosis takes several years to develop, and it is impractical to perform such long studies to identify treatment benefits. Therefore, to expedite the process and deliver new drugs to patients, biopharmaceutical companies have to consider surrogate endpoints that are reliable, can be obtained within a reasonable amount of time and are associated with progression of the disease.
A range of liver-related outcomes
- Portal hypertension. Chronic injury to the liver results in a wounding response that leads to fibrosis, scarring and ultimately replacement of normal liver architecture with regenerative nodules. As a result of these changes, portal hypertension develops.
- The accumulation of fluid in the abdomen results from portal hypertension. Using diuretics and reducing sodium intake often helps, but some cases are difficult to treat.
Novel biomarkers represent a promising means to improve diagnosis of nonalcoholic steatohepatitis (NASH). Currently, a definitive diagnosis requires a liver biopsy, a surgical procedure with many limitations. There are a variety of biomarkers that can assess liver status, but they do not always distinguish between patients with NASH and those with other disorders. Advanced imaging techniques, while useful for evaluating some liver features, can be impractical and costly.
The ultimate goal is to find noninvasive biomarkers that clearly show if the patient has steatohepatitis or liver fibrosis associated with nonalcoholic fatty liver disease (NAFLD). Recent studies suggest that nuclear magnetic resonance (NMR) spectroscopy, microRNA tests and genotyping may prove to be useful tools. Incorporating additional biomarkers into clinical trials can give biopharmaceutical companies an early indication of whether a compound is efficacious — and provide the confidence to move forward to the next phase of clinical testing. Continue reading
The pre-clinical phase of development for non-alcoholic steatohepatitis (NASH) drugs faces many challenges. Biopharmaceutical companies have several options for rodent models, but they must weigh factors such as customization versus speed before deciding on the best approach.
Some of the challenges include:
- Diet: There is no prevailing wisdom in the field suggesting that one induction diet is superior to another.
- Duration of disease induction: Depending on the type of diet, it will take 6 to 9 months for models to exhibit NASH-like features.
- Translation: Novel biomarkers used in human clinical trials need further validation in rodent models.