Futibatinib (Lytgobi®) is an oral, covalently binding, irreversible inhibitor of fibroblast growth factor receptor (FGFR)1-4 that is being developed by Taiho Oncology and Taiho Pharmaceutical for the treatment of cancers, including cholangiocarcinoma, breast cancer, gastric cancer, urothelial cancer, oesophageal cancer and non-small cell lung cancer. Futibatinib is a small molecule kinase inhibitor of FGFR 1, 2, 3, and 4 with IC50 values of less than 4 nM. Futibatinib covalently binds FGFR. Constitutive FGFR signaling can support the proliferation and survival of malignant cells. Futibatinib inhibited FGFR phosphorylation and downstream signaling and decreased cell viability in cancer cell lines with FGFR alterations including FGFR fusions/rearrangements, amplifications, and mutations. Futibatinib demonstrated anti-tumor activity in mouse and rat xenograft models of human tumors with activating FGFR genetic alterations. Futibatinib was approved in the USA on 30 September 2022 for the treatment of adult patients with previously treated, unresectable, locally advanced or metastatic intrahepatic cholangiocarcinoma harbouring FGFR2 gene fusions or other rearrangements.

Trofinetide (NNZ 2566), a proprietary small molecule analogue of glycine-proline-glutamate [Glypromate®], is being developed by Neuren Pharmaceuticals and Acadia Pharmaceuticals for the treatment of brain injuries, fragile X syndrome, Rett syndrome. Trofinetide is a synthetic analogue of a naturally occurring neurotrophic peptide derived from IGF-1, a growth factor produced by brain cells. In animal models, trofinetide exhibits a wide range of important effects including inhibiting neuroinflammation, normalizing the role of microglia and correcting deficits in synaptic function. Trofinetide was approved in March 2023 in the USA for the treatment of Rett syndrome in adult and pediatric patients 2 years of age and older.

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.

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.

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.

Fexinidazole is an antiparasitic drug, which is in the phase III of clinical trial for the treatment of Human African Trypanosomiasis, and in the phase II for the treatment Disease, Chagas and Visceral Leishmaniosis. However, for the Visceral Leishmaniosis, studies were terminated, due to lack of efficacy. Fexinidazole rapidly metabolized to two active metabolites, a sulfone and a sulfoxide, which prolong the pharmacological action of parent drug. These metabolites retaine trypanocidal activity but are less effective in nifurtimox-resistant lines, which can lead to the potential danger in the use of fexinidazole as a monotherapy.

Bristol-Myers Squibb developed Rimegepant, also known as BMS-927711. Rimegepant is a potent, selective, competitive and orally active calcitonin gene-related peptide (CGRP) antagonist in clinical trials for treating migraine. Rimegepant has shown in vivo efficacy without vasoconstrictor effect; it is superior to placebo at several different doses (75 mg, 150 mg, and 300 mg) and has an excellent tolerability profile.

PF-04449913 is a potent and selective inhibitor of the Hh signaling pathway through binding to the target, smoothened. PF-04449913 inhibits Hh signaling in vitro and has demonstrated significant antitumor activity in vivo. In the clinic, PF-04449913 is being evaluated both in hematological and solid malignancies, with a phase II trial currently underway in both fit and unfit patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS). Treatment-related adverse-events were nausea, dizziness, somnolence, QT prolongation and pruritus. Based on pre-clinical assessments, CYP3A4 is believed to be primarily involved in the metabolism of PF-04449913 that is why PF-04449913 plasma exposures and peak concentrations were increased following concurrent administration of ketoconazole (CYP3A4 inhibitor).