GSK2879552 – is an orally available, irreversible, inhibitor of lysine specific demethylase 1 (LSD1), with potential antineoplastic activity. Upon administration, GSK2879552 binds to and inhibits LSD1, a demethylase that suppresses the expression of target genes by converting the dimethylated form of lysine at position 4 of histone H3 (H3K4) to mono- and unmethylated H3K4. LSD1 inhibition enhances H3K4 methylation and increases the expression of tumor-suppressor genes. This may lead to an inhibition of cell growth in LSD1-overexpressing tumor cells. LSD1, overexpressed in certain tumor cells, plays a key role in tumor cell growth and survival. On October 2016 GlaxoSmithKline plans a phase I/II trial for Myelodysplastic syndromes (Monotherapy, Combination therapy, Second-line therapy or greater) in USA, Canada and Europe (PO) (NCT02929498).

R428 (BGB324) is an inhibitor of Axl with IC50 of 14 nM. R428 was originated in Rigel Pharmaceuticals and was licensed to BerGenBio, which initiated clinical trials for the treatment of non-small cell lung cancer, metastatic melanoma and acute myeloid leukaemia.

AMG-925, a dual FLT3/CDK4 inhibitor, has been developed to overcome resistance to FLT3 inhibitors, which is a serious clinical issue in treating acute myelogenous leukemia (AML). AMG-925 inhibits FLT3, including many FLT3 mutants reported to date. AMG-925 inhibits the proliferation of a panel of human tumor cell lines including Colo205 (Rb(+)) and U937 (FLT3(WT)) and induced cell death in MOLM13 (FLT3(ITD)) and even in MOLM13 (FLT3(ITD, D835Y)), which exhibits resistance to a number of FLT3 inhibitors currently under clinical development. At well-tolerated doses, AMG-925 leads to significant growth inhibition of MOLM13 xenografts in nude mice, and the activity correlates with inhibition of STAT5 and Rb phosphorylation. AMG-925 is in Phase I clinical trials for the treatment of Acute myeloid leukaemia.

p53 is a critical tumor suppressor and is the most frequently inactivated gene in human cancer. Inhibition of the interaction of p53 with its negative regulator MDM2 represents a promising clinical strategy to treat p53 wild-type tumors. AMG 232 is a potential best-in-class inhibitor of the MDM2-p53 interaction and is currently in clinical trials. Based on X-ray cocrystal structures a model of AMG 232 bound to MDM2 was developed. The model shows that the m-chlorophenyl, the p-chlorophenyl, and C-linked isopropyl fragments of AMG 232 bind to the Leu 26(p53), Trp 23(p53), and Phe 19(p53) pockets of MDM2, respectively. The carboxylic acid forms a salt bridge with His 96 and the isopropyl sulfone forms a novel interaction with the glycine shelf region of MDM2. AMG 232 in phase II in combination with trametinib and dabrafenib in subjects with metastatic melanoma; in phase I for the treatment of solid tumors, multiple myeloma and Acute Myeloid Leukemia.

BVD-523 potently and selectively inhibits ERK1 and ERK2 kinases in a reversible, ATP-competitive fashion. Consistent with its mechanism of action, BVD-523 inhibits signal transduction, cell proliferation, and cell survival, most potently in cell lines bearing mutations that activate MAPK pathway signaling. Similarly, single-agent BVD-523 inhibits tumor growth in vivo in BRAF-mutant melanoma and colorectal xenografts as well as in KRAS-mutant colorectal and pancreatic models. BioMed Valley Discoveries is developing ulixertinib, a potent and selective small molecule inhibitor of ERK 1 and 2 kinases, as an oral treatment for cancers harbouring mutations in the MAPK signaling pathway. Phase I/II development of the drug for advanced cancers including, acute myeloid leukaemia and myelodysplastic syndromes is underway in the US. A phase I trial is underway in the US for pancreatic cancer.

RO-5045337 (RG7112) is a small molecule that binds to a MDM2, a negative regulator of tumor-supressor protein p53. It was discovered by Roche and investigated in clinical trials against solid tumors, leukemias and sarcomas.

Amgen is developing AMG-900, an orally active, small molecule aurora kinase A, B and C inhibitor for the treatment of solid tumours and haematological malignancies. In tumor cells, AMG-900 inhibited autophosphorylation of aurora-A and -B as well as phosphorylation of histone H3 on Ser(10), a proximal substrate of aurora-B. The predominant cellular response of tumor cells to AMG-900 treatment was aborted cell division without a prolonged mitotic arrest, which ultimately resulted in cell death. AMG-900 inhibited the proliferation of 26 tumor cell lines, including cell lines resistant to the antimitotic drug paclitaxel and to other aurora kinase inhibitors (AZD1152, MK-0457, and PHA-739358), at low nanomolar concentrations. Furthermore, AMG-900 was active in an AZD1152-resistant HCT116 variant cell line that harbors an aurora-B mutation (W221L). Oral administration of AMG-900 blocked the phosphorylation of histone H3 in a dose-dependent manner and significantly inhibited the growth of HCT116 tumor xenografts. Importantly, AMG-900 was broadly active in multiple xenograft models, including 3 multidrug-resistant xenograft models, representing 5 tumor types. AMG-900 has entered clinical evaluation in adult patients with advanced cancers and has the potential to treat tumors refractory to anticancer drugs such as the taxanes.

MK-8776 (SCH900776) is inhibitor of CHK1. It was tested in clinical trials against acute myeloid leukaemia, solid tumors and lymphoma.

AZD-1208 is an orally available, potent and highly selective Pim inhibitor that effectively inhibits all three isoforms. AZD-1208 inhibits the growth of several AML cell lines and sensitivity correlates with the level of Pim-1 expression, STAT5 activation and presence of protein tyrosine kinase mutation. AZD-1208 causes cell cycle arrest and apoptosis in MOLM-16 cells in culture. This is accompanied by a dose-dependent reduction in phosphorylation of BAD, 4EBP1 and p70S6K. In addition, AZD-1208 leads to potent inhibition of colony growth of primary AML cells from bone marrow aspirates and downregulates phosphorylation of Pim targets. AZD-1208 was in Phase 1 trials to evaluate the safety and tolerability profile and to determine the maximum tolerated dose (MTD). There were two trials where AZD-1208 had been administered orally in AML and solid tumour (of all types) patients. The studies had being discontinued due to safety reasons.

I-BET-762 (GSK 525762) is a small molecule benzodiazepine, by 'mimicking' acetylated histones interferes with the recognition of acetylated histones by BET family of bromodomains (BRD2, BRD3, and BRD4), which disrupts chromatin remodeling and gene expression. Prevention of the expression of certain growth-promoting genes may lead to an inhibition of tumour cell growth. GlaxoSmithKline is developing GSK 525762 for the oral treatment of solid tumours and haematological malignancies.