Treosulfan (l-threitol-1,4-bis-methanesulfonate; dihydroxybusulfan) is a prodrug of a bifunctional alkylating cytotoxic agent that is approved for the treatment of ovarian carcinomas in a number of European countries. The antitumor activity of treosulfan has been shown in a variety of solid tumors. It is used for the treatment of all types of ovarian cancer, either supplementary to surgery or palliatively. Treosulfan is a prodrug that is converted nonenzymatically first to a mono-epoxide – (2S,3S)- 1,2-epoxy-3,4-butanediol-4-methanesulfonate – and then to a diepoxide – l-diepoxybutane, which is also a metabolite of butadiene – under physiological conditions. Such conversions are assumed to account for the alkylating and therapeutic activities of treosulfan.

Xanomeline (LY-246,708) is an orthosteric muscarinic acetylcholine receptor (mAChR) agonist, often referred to as M1/M4-preferring. It is also known to act as a M5 receptor antagonist. Xanomeline was studied in clinical trials phase I in schizophrenia. In Phase II clinical trials in Alzheimer’s patients, xanomeline significantly improved several measures of cognitive function, yet produced unwanted side effects that limited patient compliance. The side effects seem to be associated with rapid metabolism of the alkyloxy side chain following oral administration, resulting in a nonselective, yet active compound with limited therapeutic utility. Despite a second Phase II clinical trial with a patch formulation, the liabilities of xanomeline still outweigh its benefits.

Gavinostat is an orally bioavailable hydroxymate inhibitor of histone deacetylase (HDAC) with potential anti-inflammatory, anti-angiogenic, and antineoplastic activities. Gavinostat inhibits class I and class II HDACs, resulting in an accumulation of highly acetylated histones, followed by the induction of chromatin remodeling and an altered pattern of gene expression. At low, nonapoptotic concentrations, this agent inhibits the production of pro-inflammatory cytokines such as tumor necrosis factor- (TNF-), interleukin-1 (IL-1), IL-6 and interferon-gamma. It is currently in phase 2 trials for Myeloproliferative disorders, Polycythaemia vera and Phase III for Duchenne muscular dystrophy announced. In clinical trials of givinostat as a salvage therapy for advanced Hodgkin's lymphoma, the most common adverse reactions were fatigue, mild diarrhea or abdominal pain, moderate thrombocytopenia, and mild leukopenia.

X-396 (Ensartinib) is a novel, potent anaplastic lymphoma kinase (ALK) small molecule tyrosine kinase inhibitor (TKI) with additional activity against MET, ABL, Axl, EPHA2, LTK, ROS1 and SLK. Ensartinib has demonstrated activity in ALK treatment naïve and previously treated patients and has a generally well tolerated safety profile. Ensartinib is currently in a global phase 3 trial in ALK positive non-small cell lung cancer (NSCLC) patients. The phase 1/2 clinical findings support the preclinical results that the use of ensartinib may result in favorable therapeutic outcomes in patients with ALK NSCLC, including patients with CNS metastases. In this study, ensartinib was generally well tolerated with the most common adverse event being a rash.

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).

Elacestrant (ER-306323 or RAD 1901 [6R)-6-(2-(N-(4-(2-(ethylamino)ethyl)benzyl)-N-ethylamino)-4-methoxyphenyl)-5,6,7,8-tetrahydronaphthalen-2-ol dihydrochloride]) is an estrogen receptor antagonist that binds to estrogen receptor-alpha (ERα). In ERpositive (ER ) HER2-negative (HER2-) breast cancer cells, elacestrant inhibited 17β-estradiol mediated cell proliferation at concentrations inducing degradation of ERα protein mediated through proteasomal pathway. Elacestrant demonstrated in vitro and in vivo antitumor activity including in ER HER2- breast cancer models resistant to fulvestrant and cyclin-dependent kinase 4/6 inhibitors and those harboring estrogen receptor 1 gene (ESR1) mutations. On January 27, 2023, the Food and Drug Administration (FDA) approved elacestrant (Orserdu, Stemline Therapeutics, Inc.) for postmenopausal women or adult men with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.

Pacritinib (SB1518), discovered in Singapore at the labs of S*BIO Pte Ltd., is an oral tyrosine kinase inhibitor (TKI) with activity against two important activating mutations: Janus Associated Kinase 2 (JAK2) and FMS-like tyrosine kinase 3 (FLT3). The JAK family of enzymes is a central component in signal transduction pathways, which are critical to normal blood cell growth and development as well as inflammatory cytokine expression and immune responses. Activating mutations of JAK2 are implicated in certain blood-related cancers, including myeloproliferative neoplasms (MPNs), leukemia and certain solid tumors. FLT3 is a gene commonly found mutated in patients with acute myeloid leukemia (AML). Pacritinib has demonstrated encouraging results in Phase 1 and 2 studies for patients with myelofibrosis and may offer an advantage over other JAK inhibitors through effective treatment of symptoms while having less treatment-emergent thrombocytopenia and anemia than has been seen in currently approved and in-development JAK inhibitors. Pacritinib is acquired by Cell Therapeutics, Inc. (CTI) and Baxter international and could effectively address an unmet medical need for patients living with myelofibrosis who face treatment-emergent thrombocytopenia on marketed JAK inhibitors. Currently Pacritinib is undergoing preregistration for myelofibrosis.

Adagrasib (KRAZATI™) is an orally available, potent, small molecule inhibitor of KRAS G12C mutant isoform being developed by Mirati Therapeutics for the treatment of solid tumours harbouring KRAS G12C oncogenic driver mutation, including non-small cell lung cancer (NSCLC) and colorectal cancer (CRC). Adagrasib is an irreversible inhibitor of KRAS G12C that covalently binds to the mutant cysteine in KRAS G12C and locks the mutant KRAS protein in its inactive state that prevents downstream signaling without affecting wild-type KRAS protein. Adagrasib inhibits tumor cell growth and viability in cells harboring KRAS G12C mutations and results in tumor regression in KRAS G12C-mutated tumor xenograft models with minimal off-target activity. In December 2022, adagrasib received its first approval in the USA for the treatment of adults with KRAS G12C-mutated locally advanced or metastatic NSCLC (as determined by an FDA approved test) who have received ≥ 1 prior systemic therapy. It was approved under accelerated approval based on objective response rate and duration of response, and its continued approval for this indication may be contingent upon verification and description of a clinical benefit in a confirmatory trial(s). The drug is under regulatory review for NSCLC in the European Union and is in development for CRC in the US. Clinical studies of adagrasib in solid tumours, including CRC, are underway in several countries.

Olutasidenib (FT-2102) is a highly potent, orally bioavailable, brain-penetrant, and selective inhibitor of mutant IDH1. Olutasidenib was designed to reduce R-2-HG and revert pathologic epigenetic modifications that impair cellular differentiation to restore regulatory enzyme function. In patients with AML, susceptible IDH1 mutations are defined as those leading to increased levels of 2-hydroxyglutarate (2-HG) in the leukemia cells and where efficacy is predicted by 1) clinically meaningful remissions with the recommended dose of olutasidenib and/or 2) inhibition of mutant IDH1 enzymatic activity at concentrations of olutasidenib sustainable at the recommended dosage according to validated methods. The most common of such mutations in patients with AML are R132H and R132C substitutions. In vitro, olutasidenib inhibited mutated IDH1 R132H, R132L, R132S, R132G, and R132C proteins; wild-type IDH1 or mutated IDH2 proteins were not inhibited. Olutasidenib inhibition of mutant IDH1 led to decreased 2-HG levels in vitro and in in vivo xenograft models. On December 1, 2022, the FDA approved olutasidenib (brand name Rezlidhia) capsules for adult patients with relapsed or refractory acute myeloid leukemia with a susceptible IDH1 mutation as detected by an FDA-approved test.