Belzutifan (PT2977) is an orally active, small molecule inhibitor of hypoxia-inducible factor (HIF)-2alpha (HIF-2a). Upon oral administration, HIF-2alpha inhibitor PT2977 binds to and blocks the function of HIF-2alpha, thereby preventing HIF-2alpha heterodimerization and its subsequent binding to DNA. This results in decreased transcription and expression of HIF-2alpha downstream target genes, many of which regulate hypoxic signaling. This inhibits cell growth and survival of HIF-2alpha-expressing tumor cells. HIF-2alpha, the alpha subunit for the heterodimeric transcription factor HIF-2, is overexpressed in many cancers and promotes tumorigenesis.

Fosdenopterin (NulibryTM) is a synthetic cyclic pyranopterin monophosphate that is being developed by Origin Biosciences (a subsidiary of BridgeBio Pharma) for the treatment of molybdenum cofactor deficiency (MoCD) type A. Patients with MoCD Type A have mutations in the MOCS1 gene leading to deficient MOCS1A/B dependent synthesis of the intermediate substrate, cPMP. Substrate replacement therapy with NULIBRY provides an exogenous source of cPMP, which is converted to molybdopterin. Molybdopterin is then converted to molybdenum cofactor, which is needed for the activation of molybdenum-dependent enzymes, including sulfite oxidase (SOX), an enzyme that reduces levels of neurotoxic sulfites. Fosdenopterin was approved by the US FDA in February 2021 for use in reducing the risk of mortality in paediatric and adult patients with MoCD type A.

Sotorasib (LUMAKRAS™) is a RAS GTPase family inhibitor being developed by Amgen for the treatment of solid tumours with KRAS mutations, including non-small cell lung cancer (NSCLC) and colorectal cancer. Sotorasib is an inhibitor of KRASG12C, a tumor-restricted, mutant-oncogenic form of the RAS GTPase, KRAS. Sotorasib forms an irreversible, covalent bond with the unique cysteine of KRASG12C, locking the protein in an inactive state that prevents downstream signaling without affecting wild-type KRAS. Sotorasib blocked KRAS signaling, inhibited cell growth, and promoted apoptosis only in KRAS G12C tumor cell lines. Sotorasib inhibited KRASG12C in vitro and in vivo with minimal detectable off-target activity. In May 2021, sotorasib was granted accelerated approval by the US FDA for the treatment of adult patients with KRAS G12C-mutated locally advanced or metastatic NSCLC, as determined by an FDA-approved test, who have received at least one prior systemic therapy.

Voclosporin (Lupkynis™) is an oral calcineurin inhibitor immunosuppressant that is being developed by Aurinia Pharmaceuticals. Voclosporin is an analogue of cyclosporine with a modification at the amino acid-1 position. The drug has been designed to show improved potency against calcineurin inhibition and better metabolic stability than cyclosporine. Although the exact mechanism of voclosporin is not yet clear, it inhibits calcineurin, thereby blocking lymphocyte proliferation and T-cell mediated immune responses, as well as increasing podocyte integrity in the kidney. In January 2021, based on positive results from the pivotal phases II and III trials, oral voclosporin received its first approval in the USA for use in combination with a background immunosuppressive therapy regimen for adults with active lupus nephritis. Voclosporin is also being explored for the novel coronavirus disease 2019 (COVID-19) in kidney transplant recipients. Clinical evaluation of voclosporin for plaque psoriasis, coronary artery restenosis and rheumatoid arthritis has been discontinued and no recent development for prevention of renal transplant rejection has been identified since 2015.

Difelikefalin (Korsuva™) is a synthetic peptide agonist of the kappa opioid receptor being developed by Cara Therapeutics for the treatment of pruritus. In August 2021, intravenous difelikefalin was approved in the USA for the treatment of moderate-to-severe pruritus associated with chronic kidney disease (CKD) in adults undergoing haemodialysis. Difelikefalin selectively acts on kappa opioid receptors in peripheral tissues, which contribute to pruritis and nociception. The activation of opioid receptors in peripheral neurons and keratinocytes reduces afferent (sensory) impulses towards the central nervous system, decreasing pain signals. Activating kappa opioid receptors on immune cells, including monocytes and T lymphocytes, decreases the release of pro-inflammatory chemicals such as prostaglandins.

Trilaciclib (Cosela™) is a small-molecule, short-acting, inhibitor of cyclin-dependent kinases (CDK) 4 and 6 developed by G1 Therapeutics for its myeloprotection and potential antitumor efficacy and safety benefits in combination with cancer chemotherapy. CDKs govern cell cycle progression, and trilaciclib induces a transient, reversible G1 cell cycle arrest of proliferating haematopoietic stem and progenitor cells in bone marrow, thus protecting them from damage during chemotherapy. In February 2021, trilaciclib received its first approval in the USA to decrease the incidence of chemotherapy-induced myelosuppression in adult patients when administered prior to a platinum/etoposide-containing regimen or topotecan-containing regimen for extensive-stage small cell lung cancer (ES-SCLC). Clinical studies in breast cancer, colorectal cancer and small cell lung cancer are underway in several countries.

MK-8031 (also known as Atogepant) is piperidinonylcarboxamideazaindane derivative patented by Merck Sharp & Dohme Corp as CGRP receptor antagonist useful for prevention and treatment of Migraine. A press release in June 2018 announced positive results for MK-8031, in a Phase 2 trial of daily use for episodic migraine prevention. MK-8031appeared to show good efficacy in migraine prevention and no significant liver toxicity signal at any dose despite daily dosing for 3 months. Phase III clinical trial was initiated in 2019 and currently in progress.

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.

Ibrexafungerp (BREXAFEMME®) is an orally active triterpenoid antifungal drug being developed by SCYNEXIS, Inc. for the treatment of fungal infections. The inhibition of β-1,3-D glucan synthetase by ibrexafungerp compromises the integrity of fungal cell walls. Ibrexafungerp has been recently approved for the treatment of vulvovaginal candidiasis (VVC), and it is the first novel antifungal drug class to be approved in more than 20 years. Food and Drug Administration's decision was based on positive results from two pivotal phase III studies in which oral ibrexafungerp proved both safe and effective in patients with vulvovaginal candidiasis. Development for the treatment of recurrent VVC and invasive fungal infections is ongoing.

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.