Losmapimod (GW856553, GSK-AHAB) is a selective, potent, and orally active p38 MAPK (p38α and p38β isoforms) inhibitor that acts by competing for the kinase ATP binding site. GlaxoSmithKline (GSK) is developing oral losmapimod for the treatment of acute coronary syndromes (phase III), chronic obstructive pulmonary disease (phase II) and primary focal segmental glomerulosclerosis (phase II). Oral losmapimod was in phase II development for the treatment of rheumatoid arthritis and major depressive disorder; however, it appears that development for these indications has been discontinued. No further development was reported for atherosclerosis, dyslipidaemia and neuropathic pain.

SAR407899 is a potent, ATP-competitive Rho kinase inhibitor. It antihypertensive action in animals. Sanofi is developing SAR 407899 for the treatment of microvascular angina (Syndrome X). It was previously being developed in clinical trials for the treatment of diabetic neuropathies, diabetic nephropathies, erectile dysfunction, pulmonary hypertension, hypertension and kidney disorders, but development was discontinued for those indications.

VX-970 (VE-822) is an ATR kinase inhibitor. VE-822 decreased maintenance of cell-cycle checkpoints, increased persistent DNA damage and decreased homologous recombination in irradiated cancer cells. Vertex Pharmaceuticals is developing VX 970 for the treatment of advanced solid tumours. Phase I/II development is underway in the US for small-cell lung cancer and in the UK for solid tumours. Phase II development of VX 970 as a combination therapy in urogenital cancer, ovarian, primary peritoneal and fallopian tube cancer indications is underway in the US.

GSK690693 is an aminofurazan derivative, a novel ATP-competitive, low-nanomolar pan-Akt kinase inhibitor. It is selective for the Akt isoforms versus the majority of kinases in other families; however, it does inhibit additional members of the AGC kinase family. GlaxoSmithKline was developing this compound for the treatment of lymphoma solid tumours but the clinical development of this compound was terminated due to the associated side-effect of transient hyperglycemia.

SNS 314 is a selective small molecule inhibitor of Aurora kinases A, B and C. The compound was being developed by Sunesis Pharmaceuticals for the treatment of cancer. Proliferating cells treated with SNS-314 bypass the mitotic spindle checkpoint and fail to undergo cytokinesis, leading to multiple rounds of endoreduplication and eventually cell death. SNS-314 inhibits tumor growth in a variety of preclinical models, and it was being tested in single agent Phase 1 studies in patients with advanced solid tumours.

Selonsertib, also known as GS-4997, is a small-molecule inhibitor of apoptosis signal-regulating kinase 1 (ASK1), which promotes inflammation, apoptosis and fibrosis in settings of increased oxidative stress associated with NASH pathogenesis. GS-4997 prevents the production of inflammatory cytokines, down-regulates the expression of genes involved in fibrosis, suppresses excessive apoptosis and inhibits cellular proliferation. GS-4997 is currently being evaluated in an ongoing Phase 2 study in patients with NASH and moderate to severe liver fibrosis.

Crenolanib is an orally active, highly selective, small molecule, next generation inhibitor of platelet-derived growth factor receptor (PDGFR) tyrosine kinase. Crenolanib, manufactured by Arog Pharmaceuticals in Dallas, is taken orally with chemotherapy. The compound is currently being evaluated for safety and efficacy in clinical trials for various types of cancer, including acute myeloid leukemia (AML), gastrointestinal stromal tumor (GIST), and glioma. Crenolanib is an orally bioavailable, selective small molecule inhibitor of type III tyrosine kinases with nanomolar potencies against platelet-derived growth factor receptors (PDGFR) (isoforms PDGFRα and PDGFRβ) and Fms-related tyrosine kinase 3 (FLT3). Besides PDGFR and FLT3, crenolanib does not inhibit any other known receptor tyrosine kinase (RTK) (e.g. VEGFR and FGFR) or any other serine/threonine kinase (e.g., Abl, Raf) at clinically achievable concentrations. Preclinical trials have shown Crenolanib to be active in inhibiting both wild-type and mutant FLT3. Crenolanib is cytotoxic to the FLT3/ITD-expressing leukemia cell lines Molm14 and MV411, with IC50s of 7 nM and 8 nM, respectively. In immunoblots, crenolanib inhibited phosphorylation of both the wild-type FLT3 receptor (in SEMK2 cells) and the FLT3/ITD receptor (in Molm14 cells) in culture medium with IC50s of 1-3 nM. Importantly, the IC50 of crenolanib against the D835Y mutated form of FLT3 was 8.8 nM in culture medium. Furthermore, crenolanib had cytotoxic activity against primary samples that were obtained from patients who had developed D835 mutations while receiving FLT3 TKIs. In vitro, the IC50 of crenolanib for inhibition of FLT3/ITD in plasma was found to be 34 nM, indicating a relatively low degree of plasma protein binding. From pharmacokinetic studies of crenolanib in solid tumor patients, steady state trough plasma levels of roughly 500 nM were found to be safe and tolerable, suggesting that crenolanib could potentially inhibit the target in vivo. Crenolanib has no significant activity against c-KIT, which may be an advantage in that myelosuppression can be avoided.1Furthermore, there was no evidence of QTc prolongation in patients treated with crenolanib. In summary, crenolanib offers a number of advantages over other FLT3 TKIs. Clinical trials of crenolanib in AML patients with FLT3 activating mutations are being planned.

Lestaurtinib (CEP-701, KT-5555) is an orally bio-available polyaromatic indolocarbazole alkaloid derived from K-252a. Lestaurtinib is a multi-targeted tyrosine kinase inhibitor which has been shown to potently inhibit FLT3 at nanomolar concentrations in preclinical studies, leading to its rapid development as a potential targeted agent for treatment of AML. Phase I studies have shown lestaturtinib to be an active agent particularly when used in combination with cytotoxic drugs. Currently, Phase II and Phase III studies are underway aiming to establish the future of this agent as a treatment option for patients with FLT3-ITD AML.

Filgotinib (GLPG0634) is a highly selective JAK1 inhibitor. GLPG0634 is a promising drug candidate for the future treatment of autoimmune and inflammatory disorders. It is in phase III clinical trials (initiated mid-2016) for the treatment of rheumatoid arthritis, Crohn's disease and ulcerative colitis. Most common adverse events observed were infections, gastrointestinal disorders and nervous system disorders.