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.

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.

XL019 is a potent and selective JAK2 inhibitor. XL019 shows 50-fold or greater selectivity for JAK2, versus a panel of over 100 serine/threonine and tyrosine kinases, including other members of the JAK family. XL019 is non-selective for JAK2V617F or wild-type JAK2 and potently inhibits STAT3 and STAT5 phosphorylation in cells harboring either JAK2V617F or wild-type JAK2. Unfortunately, XL019 treatment was associated with the unexpected occurrence of neurotoxicity. Phase I clinical trials have been terminated.

CGM-097, a novel, highly optimized, and selective inhibitor of the p53-Mdm2 interaction. CGM-097 binds to human Mdm2 protein with a Ki value of 1.3 nM, activates p53 in human cells and induces robust p53-dependent cell cycle arrest and apoptosis in human p53 wild-type tumor cells. Its activity and selectivity has been tested and confirmed across a large panel of cancer cell lines from the Cancer Cell Line Encyclopedia. CGM-097 displays desirable pharmacokinetic and pharmacodynamic profiles in animals together with excellent oral bioavailability, which triggers rapid and sustained activation of p53-dependent pharmacodynamic biomarkers resulting in tumor regression in multiple xenografted models of p53 wild-type human cancer. The validation and understanding of its mechanism of action, the overall favorable drug-like properties and the characterization of its on-target toxicological profile in preclinical species strongly supported the initiation of Phase I clinical trials with CGM-097 in pre-selected patients with p53 wild-type tumors.

PF-06840003 is a highly selective orally bioavailable Indoleamine 2,3-dioxygenase-1 (IDO-1) inhibitor with a potent antineoplastic activity. PF-06840003 reversed IDO-1-induced T-cell anergy in vitro. In vivo, PF-06840003 reduced intratumoral kynurenine levels in mice by >80% and inhibited tumor growth in multiple preclinical syngeneic models in mice, in combination with immune checkpoint inhibitors. A Phase 1 study of PF-06840003 in patients with Malignant Gliomas is ongoing.

NLG919 is a novel small-molecule IDO-pathway inhibitor. NLG919 potently inhibits this pathway in vitro and in cell-based assays. It is orally bioavailable and has a favorable pharmacokinetic and toxicity profile. In mice, a single oral administration of NLG919 reduces the concentration of plasma and tissue Kyn by ∼ 50%. Using IDO-expressing human monocyte-derived DCs in allogeneic MLR reactions, NLG919 potently blocked IDO-induced T cell suppression and restored robust T cell responses with an ED50=80 nM. Similarly, using IDO-expressing mouse DCs from tumor-draining lymph nodes, NLG919 abrogated IDO-induced suppression of antigen-specific T cells (OT-I) in vitro. In vivo, in mice bearing large established B16F10 tumors, administration of NLG919 markedly enhanced the anti-tumor responses of naïve, resting pmel-1 cells to vaccination with cognate hgp100 peptide plus CpG-1826 in IFA

VTP-27999 is an alkyl amine renin inhibitor. This compound demonstrated excellent selectivity over related and unrelated off-targets, >15% oral bioavailability in three species, oral efficacy in a double transgenic rat model of hypertension, and good exposure in humans. Vitae Pharmaceuticals was developing VTP 27999 for the treatment of chronic kidney disease. VTP 27999 was in phase I clinical development in the US. However, the product is no more on the company pipeline and it appears that the development has been discontinued.

GSK-2256294 is a potent, reversible, tight binding inhibitor of isolated recombinant human sEH (soluble epoxide hydrolase) (IC50 = 27 pM; t1/2 = 121 min) and displays potent inhibition against the rat (IC50 = 61 pM) and murine (IC50 = 189 pM) orthologs of sEH. GSK-2256294A also displays potent cellular inhibition (IC50 = 0.66 nM) of sEH in an assay developed using a cell line transfected with the human sEH enzyme. GSK-2256294 was well-tolerated and demonstrated sustained inhibition of sEH enzyme activity. These data support further investigation in patients with endothelial dysfunction or abnormal tissue repair, such as diabetes, wound healing or COPD. GSK-2256294 is in phase I clinical trials for the treatment of COPD.

HSP-990 is an oral Hsp90 inhibitor being developed by Novartis in a collaboration with Vernalis. It is also known by NVP-HSP990. HSP-990 is an inhibitor of human heat-shock protein 90 (Hsp90) with potential antineoplastic activity. Hsp-990 binds to and inhibits the activity of Hsp90, which may result in the proteasomal degradation of oncogenic client proteins, including HER2/ERBB2, and the inhibition of tumor cell proliferation. Hsp90, upregulated in a variety of tumor cells, is a molecular chaperone that plays a key role in the conformational maturation, stability and function of oncogenic signaling proteins, such as HER2/ERBB2, AKT, RAF1, BCR-ABL, and mutated p53, as well as many other molecules that are important in cell cycle regulation and/or immune responses.

Merestinib (LY2801653) is a small molecule that has been shown in vitro to be a reversible type II ATP-competitive slowoff inhibitor of MET tyrosine kinase with a dissociation constant (Ki) of 2 nM, a pharmacodynamic residence time (Koff) of 0.00132 min−1 and a half-life (t1/2) of 525 min. Preclinical testing also has shown merestinib to inhibit several other receptor tyrosine oncokinases including MST1R, FLT3, AXL, MERTK, TEK, ROS1, NTRK1/2/3, and DDR1/2 and the serine/threonine kinases MKNK1/2. Merestinib is being investigated in a phase II clinical trials in patients with biliary tract cancer, non-small cell lung cancer and solid tumours.