Nonalcoholic steatohepatitis (NASH) is the most severe form of nonalcoholic fatty liver disease (NAFLD) and is associated with a high risk of progression to NASH related cirrhosis and NASH related hepatocellular carcinoma.1–3 NASH is considered as the hepatic component of the metabolic syndrome, which is a clinical syndrome characterized by obesity, dyslipidemia, type 2 diabetes mellitus (T2DM), and hypertension.1–3 Patients with NASH are at risk not only for the liver-related morbidity and mortality but also at a higher risk of morbidity and mortality due to cardiovascular diseases (CVDs).1–3
Histologically, NASH is defined as steatosis and inflammation associated with the presence of one of the three additional features: mallory hyaline, ballooning of hepatocytes, and fibrosis.2, 3 NASH mainly develops due to excess adiposity and systemic insulin resistance.4 The pathogenesis of NASH initiates with increased delivery of free fatty acids (FFA), carbohydrates, inflammatory cytokines and gut-microbiome-derived products such as endotoxin to the liver.4 This leads to an overloading of the hepatocellular metabolic machinery, which results in accumulation of lipids (mainly triglycerides) and induces cell stress that can trigger inflammatory and apoptotic signaling.4 Further, inflammation leads to fibrogenic remodeling, which progresses to cirrhosis.4
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors involved in the transcriptional regulation of glucose homeostasis, lipid metabolism, inflammation, atherosclerosis, and energy balance.2 PPAR agonists have the potential for treatment of NASH as they could act at various targets involved in the pathogenesis of NASH.2, 3
Saroglitazar is a dual PPAR alpha/gamma (PPAR α/γ) agonist (predominant PPAR-α and moderate PPAR-γ).5 Through its PPAR-α agonist action, Saroglitazar increases lipoprotein lipase activity and thereby reduces serum triglyceride levels and very low-density lipoprotein cholesterol (VLDL-C) levels, and increases high-density lipoprotein cholesterol (HDL-C) levels.5 Saroglitazar, through its PPAR-γ agonist action, improves insulin sensitivity in peripheral tissues, increases glucose uptake and reduces blood glucose levels.5 Overall, Saroglitazar improves lipid and glycemic profiles without significant increase in body weight and edema/fluid retention (commonly seen in PPAR-γ agonists such as thiazolidinediones).5–7
Saroglitazar has the potential to provide therapeutic benefit all along the pathologic spectrum of insulin resistance, diabetic dyslipidemia, T2DM, NAFLD and NASH.5–8 Clinical development has been completed in many of these indications and Saroglitazar has received marketing approval in a few countries.5–8
Diabetic dyslipidemia was the first indication for which clinical development was completed and in clinical studies completed in India, Saroglitazar improved dyslipidemia by reducing triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), VLDL-C, non HDL-C and increasing HDL-C and improved glycemic indices by reducing fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1c).5–7 Subsequent to the completion of the randomized controlled studies and marketing approval, numerous investigator initiated studies were performed across India leading to a considerable data of real world evidence.8 In an integrated analysis of real world clinical studies, which included 18 such studies, involving about 5,800 patients, effects of Saroglitazar on lipid and glycemic parameters in patients with diabetic dyslipidemia were analysed.8 Saroglitazar effectively improved lipid and glycemic parameters in patients with diabetic dyslipidemia from 12 weeks upto to 58 weeks of therapy in different IIT’s.8 Across these studies it reduced mean triglyceride levels by 45–62%, LDL-C levels by 11–27%, total cholesterol levels by 17–26%, non-HDL-C levels by 21–36%, HbA1c levels by 0.7–1.6%, and increased mean HDL-C levels (up to 9%) from baseline.8 It also reduced mean alanine aminotransferase (ALT) levels by 28–67% in NAFLD patients with diabetic dyslipidemia.8 Saroglitazar use was not associated with significant change in body weight and significant adverse events (AEs)/cardiovascular AEs.8
Saroglitazar is currently approved in India for treating “diabetic dyslipidemia and hypertriglyceridemia in T2DM not controlled by statin” [February 2013], “add-on therapy to metformin for treatment of T2DM” [January 2020], “non-cirrhotic NASH” [March 2020]. In addition, Saroglitazar has been approved in Mexico [October 2017], Burundi [August 2018] and Kenya [June 2018] for “diabetic dyslipidemia and hypertriglyceridemia with T2DM not controlled by statin”. [data on file]
This article aims to discuss the efficacy of Saroglitazar in NASH in the pre-clinical animal models and the phase 2 and 3 clinical trials. We believe that such a comprehensive discussion of the pre-clinical efficacy and the clinical efficacy in the same article, in which the effect on the typical pathological features of NASH can be correlated and understood, will provide the scientific community a comprehensive and holistic understanding of the effect of Saroglitazar in NASH.4, 9, 10
All the data depicted and discussed in this article are ‘data on file’. The pre-clinical DIAMOND mice model study results have been published in Scientific Reports (a nature research journal)4 / presented at the Liver Meeting 2018, AASLD, the USA (Abstract # 1297, 1768, and 1795). The data from the phase 2 clinical trial though not published anywhere as on original investigation, but was presented at the 5th Annual Meeting of EASL NAFLD Study Group 2017. The data from the phase 3 clinical trial has not been published anywhere as on original investigation, but was accepted as an oral presentation at the 29th Annual Conference of Asian Pacific Association for the Study of the Liver (APASL) at Bali, Indonesia.