The thiazolidinediones, abbreviated as TZD, also known as glitazones after the prototypical drug ciglitazone, are a class of heterocyclic compounds consisting of a five-membered C3NS ring. The term usually refers to a family of drugs used in the treatment of diabetes mellitus type 2 that were introduced in the late 1990s.
Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver. It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build up in the liver, a condition called cholestasis. Further slow damage to the liver tissue can lead to scarring, fibrosis, and eventually cirrhosis.
Fatty liver disease (FLD), also known as hepatic steatosis and steatotic liver disease (SLD), is a condition where excess fat builds up in the liver. Often there are no or few symptoms. Occasionally there may be tiredness or pain in the upper right side of the abdomen. Complications may include cirrhosis, liver cancer, and esophageal varices.
Metabolic dysfunction–associated steatotic liver disease (MASLD) is the name adopted in 2023 for the condition previously known as non-alcoholic fatty liver disease (NAFLD). This condition is diagnosed when there is excessive fat build-up in the liver, and at least one metabolic risk factor. When there is also moderate alcohol use, the term MetALD is used, and these are differentiated from alcoholic liver disease (ALD) when this is the sole cause of steatotic liver disease. The terms non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis have been used to describe different severities, with the latter indicating the presence of further liver inflammation. NAFL is less dangerous than NASH and usually does not progress towards it, but this progression may eventually lead to complications such as cirrhosis, liver cancer, liver failure, or cardiovascular disease.
Glucagon-like peptide-1 (GLP-1) receptor agonists, also known as GLP-1 analogs, GLP-1DAs or incretin mimetics, are a class of drugs that reduce blood sugar and energy intake by activating the GLP-1 receptor. They mimic the actions of the endogenous incretin hormone GLP-1 that is released by the gut after eating.
Cirrhosis, also known as liver cirrhosis or hepatic cirrhosis, and end-stage liver disease, is the impaired liver function caused by the formation of scar tissue known as fibrosis due to damage caused by liver disease. Damage to the liver leads to repair of liver tissue and subsequent formation of scar tissue. Over time, scar tissue can replace normal functioning tissue, leading to the impaired liver function of cirrhosis. The disease typically develops slowly over months or years. Early symptoms may include tiredness, weakness, loss of appetite, unexplained weight loss, nausea and vomiting, and discomfort in the right upper quadrant of the abdomen. As the disease worsens, symptoms may include itchiness, swelling in the lower legs, fluid build-up in the abdomen, jaundice, bruising easily, and the development of spider-like blood vessels in the skin. The fluid build-up in the abdomen may develop into spontaneous infections. More serious complications include hepatic encephalopathy, bleeding from dilated veins in the esophagus, stomach, or intestines, and liver cancer.
Seladelpar is a PPARδ receptor agonist that is being investigated for drug use by Metabolex. According to a press release they are examining its potential use for the treatment of dyslipidemia, metabolic syndrome, type 2 diabetes, and non-alcoholic steatohepatitis (NASH). The compound was licensed from Janssen Pharmaceutica NV. The drug completed a phase II trial for primary biliary cholangitis. "Seladelpar demonstrated robust, dose-dependent, clinically significant, and durable improvements in biochemical markers of cholestasis and inflammation in patients with PBC at risk of disease progression. Seladelpar appeared safe and well tolerated and was not associated with any increase in pruritus." A phase III trial in patients with PBC also found reduced pruritus and improved liver biochemistry, despite being terminated early.
Saroglitazar is a drug for the treatment of type 2 diabetes mellitus and dyslipidemia. It is approved for use in India by the Drug Controller General of India. Saroglitazar is indicated for the treatment of diabetic dyslipidemia and hypertriglyceridemia with type 2 diabetes mellitus not controlled by statin therapy. In clinical studies, saroglitazar has demonstrated reduction of triglycerides (TG), LDL cholesterol, VLDL cholesterol, non-HDL cholesterol and an increase in HDL cholesterol a characteristic hallmark of atherogenic diabetic dyslipidemia (ADD). It has also shown anti-diabetic medication properties by reducing the fasting plasma glucose and HBA1c in diabetes patients.
Obeticholic acid (OCA), sold under the brand name Ocaliva, is a semi-synthetic bile acid analogue which has the chemical structure 6α-ethyl-chenodeoxycholic acid. It is used as a medication used to treat primary biliary cholangitis. Intercept Pharmaceuticals Inc. hold the worldwide rights to develop OCA outside Japan and China, where it is licensed to Dainippon Sumitomo Pharma.
Tropifexor is an investigational drug that acts as an agonist of the farnesoid X receptor (FXR). It was discovered by researchers from Novartis and Genomics Institute of the Novartis Research Foundation. Its synthesis and pharmacological properties were published in 2017. It was developed for the treatment of cholestatic liver diseases and nonalcoholic steatohepatitis (NASH). In combination with cenicriviroc, a CCR2 and CCR5 receptor inhibitor, it is undergoing a phase II clinical trial for NASH and liver fibrosis.
Nidufexor (LMB-763) is a drug which acts as a partial agonist of the farnesoid X receptor (FXR). It has reached Phase II clinical trials for the treatment of diabetic nephropathy and nonalcoholic steatohepatitis.
Cilofexor is a nonsteroidal farnesoid X receptor (FXR) agonist in clinical trials for the treatment of non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), and primary sclerosing cholangitis (PSC). It is being investigated for use alone or in combination with firsocostat, selonsertib, or semaglutide. In rat models and human clinical trials of NASH it has been shown to reduce fibrosis and steatosis, and in human clinical trials of PSC it improved cholestasis and reduced markers of liver injury.
Resmetirom is an experimental drug for the treatment of non-alcoholic steatohepatitis (NASH). It is a selective agonist of thyroid hormone receptor-β which increases hepatic fat metabolism and reduces lipotoxicity.
Efocipegtrutide (HM15211) is a triple agonist of the glucagon, GIP, and glucagon-like peptide 1 receptors. It is being studied for obesity and nonalcoholic steatohepatitis.
Pegozafermin (BIO89-100) is a long-acting, glycopegylated FGF21 analog developed for the treatment of nonalcoholic steatohepatitis and hypertriglyceridemia.
PXL065 (deuteropioglitazone) is an experimental drug for the treatment of nonalcoholic steatohepatitis (NASH). It is a deuterated derivative of the (R)-enantiomer of pioglitazone that is designed to have a better safety profile than pioglitazone itself.
Aldafermin is a fibroblast growth factor 19 (FGF19) analogue developed for non-alcoholic steatohepatitis.
EDP-305 is a non-bile acid farnesoid X receptor (FXR) agonist developed by Enanta Pharmaceuticals for non-alcoholic fatty liver disease. According to preclinical research CYP3A4 is the main enzyme used to metabolize the drug and there is a low potential for drug interactions.
Azemiglitazone (MSDC-0602) is a novel insulin sensitizer designed to retain the effect of thiazolidinediones on mitochondrial pyruvate carriers with limited PPAR-gamma binding. It is hoped to have fewer adverse effects than the thiazolidinediones and is being developed by Cirius Therapeutics for type 2 diabetes and non-alcoholic fatty liver disease. It is formulated as its potassium salt, azemiglitazone potassium (MSDC-0602K).
HU6 is a prodrug of the mitochondrial uncoupler 2,4-dinitrophenol (DNP) that is intended to "minimize the rapid absorption and high peak blood concentrations of DNP to provide a wider therapeutic index and improve safety." Developed by Rivus Pharmaceuticals, the drug is tested to reduce weight and liver fat in humans with risk factors for metabolic dysfunction-associated steatohepatitis. In a phase 2a trial, the higher dosage levels reduced liver fat on average by more than 30 percent and also reduced body weight significantly. A phase 2b trial was launched in late 2023.
