Vorasidenib (also known as AG 881) was developed as an isocitrate dehydrogenase (IDH) type 1 in the cytoplasm and type 2 in the mitochondria, with potential antineoplastic activity. It is known that IDH is an essential enzyme for cellular respiration in the tricarboxylic acid (TCA) cycle. Isocitrate dehydrogenases 1 and 2 (IDH1/2) are homodimeric enzymes that catalyze the conversion of isocitrate to α-ketoglutarate (α-KG) in the tricarboxylic acid cycle. Vorasidenib participated in phase I clinical trials in patients with advanced hematologic malignancies and in gliomas.

Momelotinib (CYT387) is an ATP-competitive small molecule that potently inhibits JAK1/JAK2 kinases. Momelotinib is developing by Gilead Sciences for the oral treatment of pancreatic and non-small cell lung cancers, and myeloproliferative disorders (including myelofibrosis, essential thrombocythaemia and polycythaemia vera).

APD-334 (Etrasimod) was discovered as part of our internal effort to identify potent, centrally available, functional antagonists of the S1P1 receptor for use as next generation therapeutics for treating multiple sclerosis (MS) and other autoimmune diseases. APD334 is a potent functional antagonist of S1P1 and has a favorable PK/PD profile, producing robust lymphocyte lowering at relatively low plasma concentrations in several preclinical species. This new agent was efficacious in a mouse experimental autoimmune encephalomyelitis (EAE) model of MS and a rat collagen induced arthritis (CIA) model and was found to have appreciable central exposure. APD-334 has therapeutic potential in immune and inflammatory-mediated diseases such as ulcerative colitis, Crohn’s disease, and atopic dermatitis.

Palovarotene (R-667, RO-3300074) was developed by Roche Holding AG as a selective retinoic acid receptor gamma agonist for the treatment of emphysema. Phase I clinical trials of palovarotene in patients with emphysema demonstrated that the drug is well tolerated, with improvements observed in markers of emphysema progression. Unlike all-trans retinoic acid, the pharmacokinetic profile of palovarotene appears to be dose-proportional. However, those studies were discontinued. Palovarotene is also being investigated in phase II of the clinical trial in the treatment of Fibrodysplasia Ossificans Progressiva (FOP). Palovarotene received Fast Track designation from the U.S. Food and Drug Administration (FDA) and orphan designations for the treatment of FOP from both the FDA and the European Medicines Agency (EMA).

A-4250 (odevixibat) is a selective inhibitor of the ileal bile acid transporter (IBAT) that acts locally in the gut. Ileum absorbs glyco-and taurine-conjugated forms of the bile salts. IBAT is the first step in absorption at the brush-border membrane. A-4250 works by decreasing the re-absorption of bile acids from the small intestine to the liver, whichreduces the toxic levels of bile acids during the progression of the disease. It exhibits therapeutic intervention by checking the transport of bile acids. Studies show that A-4250 has the potential to decrease the damage in the liver cells and the development of fibrosis/cirrhosis of the liver known to occur in progressive familial intrahepatic cholestasis. A-4250 is a designated orphan drug in the USA for October 2012. A-4250 is a designated orphan drug in the EU for October 2016. A-4250 was awarded PRIME status for PFIC by EMA in October 2016. A-4250 is in phase II clinical trials by Albireo for the treatment of primary biliary cirrhosis (PBC) and cholestatic pruritus. In an open label Phase 2 study in children with cholestatic liver disease and pruritus, odevixibat showed reductions in serum bile acids and pruritus in most patients and exhibited a favorable overall tolerability profile.

Maralixibat (Livmarli™) is a potent, apical, sodium‐dependent, bile acid transporter competitive inhibitor with minimal systemic absorption being developed by Mirum Pharmaceuticals for the treatment of rare cholestatic liver diseases including Alagille syndrome (ALGS), progressive familial intrahepatic cholestasis (PFIC) and biliary atresia. Maralixibat received its first approval on 29 September 2021, in the USA, for use in the treatment of cholestatic pruritus in patients with ALGS 1 year of age and older. Maralixibat is also under regulatory review for ALGS in Europe, and clinical development for cholestatic liver disorders including ALGS in patients under 1 year of age, PFIC and biliary atresia is continuing in several other countries. This article summarises the milestones in the development of maralixibat leading to this first approval for ALGS.

Finerenone (Kerendia®), a first-in-class, orally administered, selective, nonsteroidal mineralocorticoid receptor antagonist (MRA), is being developed by Bayer HealthCare Pharmaceuticals for the treatment of diabetic kidney disease (DKD) and heart failure (HF), including chronic HF (CHF). Finerenone blocks MR mediated sodium reabsorption and MR overactivation in both epithelial (e.g., kidney) and nonepithelial (e.g., heart, and blood vessels) tissues. MR overactivation is thought to contribute to fibrosis and inflammation. Finerenone has a high potency and selectivity for the MR and has no relevant affinity for androgen, progesterone, estrogen, and glucocorticoid receptors. Finerenone has been approved in the USA to reduce the risk of sustained estimated glomerular filtration rate (eGFR) decline, end stage renal disease (ESRD), cardiovascular death, nonfatal myocardial infarction (MI), and hospitalization for HF in adults with chronic kidney disease (CKD) associated with type 2 diabetes (T2D). Finerenone is undergoing regulatory assessment in the EU and in China. A phase III trial is investigating finerenone in patients who have HF with preserved ejection fraction.

KD025 is an orally available, selective small molecule inhibitor of ROCK2 (Rho-associated coiled-coil kinase 2), a molecular target in multiple autoimmune, fibrotic and neurodegenerative diseases. KD025 is the only ROCK2-specific inhibitor in the clinical trials. KD025 down-regulates the IL-17 and IL-21 secretion in human PBMCs, and leads to down-regulation of STAT3 phosphorylation, IRF4, and RORγt expression in CD4+ T cells. Kadmon Pharmaceuticals initiated phase II clinical trials of KD025 for the treatment of Graft-versus-host disease; Idiopathic pulmonary fibrosis; Plaque psoriasis.

Bempedoic acid (also known as ETC-1002) is a novel investigational drug being developed for the treatment of dyslipidemia, hypercholesterolemia and other cardio-metabolic risk factors. The hypolipidemic, anti-atherosclerotic, anti-obesity, and glucose-lowering properties of ETC-1002, characterized in preclinical disease models, are believed to be due to dual inhibition of sterol and fatty acid synthesis and enhanced mitochondrial long-chain fatty acid β-oxidation. Investigations into the mechanism of action revealed that bempedoic acid-free acid activates AMP-activated protein kinase in a Ca(2+)/calmodulin-dependent kinase β-independent and liver kinase β-1-dependent manner, without detectable changes in adenylate energy charge. In the liver, bempedoic acid is also converted to a coenzyme A (CoA) derivative (ETC-1002-CoA )which directly inhibits ATP citrate lyase (ACL), a key enzyme that supplies a substrate for cholesterol and fatty acid synthesis in the liver. Inhibition of ACL by ETC-1002-CoA results in reduced cholesterol synthesis and upregulation of LDL receptor activity in the liver. This promotes the removal of LDL-C from the blood.