AZD-3759 is an oral inhibitor of both wild-type and mutant EGFR with IC50 values in nanomolar range. The drug was discovered by AstraZeneca for the treatment of non-small-cell lung cancer with CNS metastases. AZD-3759 can penetrate the blood-brain barrier and was confirmed to be effective in vitro with NSCLC cell lines as well as in mouse model of brain metastases. AZD-3759 is currently in Phase 1 clinical trial.

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.

Glesatinib (MGCD265) is an orally bioavailable, small-molecule, multitargeted tyrosine kinase inhibitor with potential antineoplastic activity. Glesatinib binds to and inhibits the phosphorylation of several receptor tyrosine kinases (RTKs), including the c-Met receptor (hepatocyte growth factor receptor); the Tek/Tie-2 receptor; vascular endothelial growth factor receptor (VEGFR) types 1, 2, and 3; and the macrophage-stimulating 1 receptor (MST1R or RON). Inhibition of these RTKs and their downstream signaling pathways may result in the inhibition of tumor angiogenesis and tumor cell proliferation in tumors overexpressing these RTKs. Studies in a gastric cancer xenograft model revealed that, in addition to the typically reported cellular activities, glesatinib in combination with erlotinib disrupted the glycolysis pathway, suggesting a novel mechanism of action for this drug. Glesatinib has been studied in a variety of advanced solid tumors including NSCLC, as a monotherapy and in combination with either docetaxel or erlotinib. In an ongoing phase 1 study in patients with MET positive or AXL-rearranged advanced solid tumors, glesatinib demonstrated preliminary single-agent activity, with all three patients with MET dysregulated NSCLC (two with METex14 alterations and one with increased GCN) showing significant tumor regression at the first assessment. A phase 2 study is currently recruiting patients with MET-dysregulated (mutated or amplified) advanced or metastatic NSCLC.

Sitravatinib (MGCD516) is a receptor tyrosine kinases (RTK) inhibitor that blocks a wide array of RTKs known to be amplified/overexpressed in sarcomas, which are key regulators of signaling pathways that lead to cell growth, survival and tumor progression. It is involved in driving sarcoma cell growth with IC50 of 3980 nM and is superior to other multi-kinase inhibitors in inhibiting cell proliferation, RTK phosphorylation, and phosphorylation of downstream effectors. The efficacy of sitravatinib was tested using a wide panel of sarcoma cell lines, including malignant peripheral nerve sheath tumor (MPNST), Ewing sarcoma (A673), osteosarcoma (Saos2), and liposarcoma (DDLS, LS141). Both in vitro and in vivo efficacy sitravatinib was significantly better that the other two multi-kinase inhibitors, imatinib and crizotinib. Sitravatinib treatment not only inhibits tumor cell proliferation at low nanomolar concentrations in vitro but also results significant tumor growth suppression in vivo in mouse xenograft models. Sitravatinib is being evaluated in a Phase 1b dose expansion cohort in selected patients with specific genetic alterations that are drivers of tumor growth, with an initial focus on Non-Small-Cell Lung carcinoma (NSCLC) and in other solid tumors where sitravatinib may confer a benefit. Its efficacy and safety is also being tested in Phase II clinical trials in patients with advanced liposarcoma as a monotherapy and NSCLC in combination with nivolumab.

PF-06747775 is an irreversible pyrrolopyrimidine inhibitor of epidermal growth factor receptor (EGFR) T790M mutants which provides potent EGFR activity against the four common mutants (exon 19 deletion (Del), L858R, and double mutants T790M/L858R and T790M/Del), selectivity over wild-type EGFR, and desirable ADME properties. The third-generation class of EGFR tyrosine kinase inhibitors PF-06747775 is a clinical candidate drug for treatment of non-small-cell lung cancer (NSCLC) driven by mutant EGFR.

Motesanib (AMG 706), a novel nicotinamide, was identified as a potent, orally bioavailable inhibitor of the VEGFR1/Flt1, VEGFR2/kinase domain receptor/Flk-1, VEGFR3/Flt4 and Kit receptors. Motesanib was expected to reduce vascular permeability and blood flow in human tumours. A phase III trial of motesanib in combination with paclitaxel and carboplatin in non-squamous NSCLC has been terminated by Takeda and subsequently the development was discontinued. Motesanib has also been investigated up to phase II in breast, thyroid, colorectal and gastrointestinal stromal tumours. However, development has been discontinued in these indications.

JNJ-38877605 is an orally available, small molecule inhibitor of the proto-oncogene c-Met (hepatocyte growth factor receptor [HGFR]) with potential antineoplastic activity. c-Met inhibitor JNJ-38877605 selectively binds to c-Met, thereby inhibiting c-Met phosphorylation and disrupting c-Met signal transduction pathways. JNJ-38877605 was in Phase I clinical trials. Combined clinical and correlative preclinical studies suggest that renal toxicity of JNJ-38877605 is caused by the formation of species-specific insoluble metabolites. These observations preclude further clinical development of JNJ-38877605.

RRX-001, also known as ABDNAZ, is a dinitroazetidine derivative with potential radiosensitizing activity. Upon administration, RRx-001 is able to dilate blood vessels, thereby increasing tumor blood flow and thus improving oxygenation to the tumor site. By increasing oxygen levels, these tumor cells may be more susceptible to radiation therapy. Tumor hypoxia is correlated with tumor aggressiveness, metastasis and resistance to radiotherapy. In mouse models, RRx-001 administered intravenously as a single agent was equipotent to cisplatin while better tolerated. RRx-001 also showed activity as a radiosensitizer in both in vitro and in vivo models. The activity of RRx-001 is thought to be associated with a nucleophilic substitution by circulating thiol compounds and covalent binding of RRx-001 to cysteinyl residues in Hb, followed by the generation of nitrogen oxides. During 2014-2015 EpicentRx has launched Phase 2 trials in brain, colorectal, non-small cell lung, small cell lung and cholangiocarcinoma both alone and in combination. The anti-proliferative effects of RRx-001 are not explainable via a single mechanism. RRx-001 exerts its anti-proliferative effect, at least partially, through interference with glucose 6 phosphate dehydrogenase (G6PD), a key enzyme in the pentose phosphate pathway, responsible for maintaining adequate levels of the major cellular reductant, NADPH.

Echinomycin is a cyclic peptide of the family of quinoxaline antibiotics that was originally isolated from Streptomyces echinatus. It is thought to act as a bifunctional DNA intercalator. Echinomycin has a binding site size of four base pairs. The strong binding sites for echinomycin contain the central two-base-pair sequence 5'-CG-3'. Echinomycin interferes with HIF-1 DNA binding in a sequence-specific fashion. It was brought into clinical trials by the NCI 20 years ago based on its antitumor activity. It has been extensively tested in phase I-II clinical trials. Nausea, vomiting, reversible liver enzyme abnormalities, and allergic reactions were the most common toxicities encountered. However, minimal or no antitumor activity was found in phase II clinical trials.

CUDC-305, is a novel heat shock protein 90 (HSP90) inhibitor with strong affinity for HSP90 alpha/beta, high oral bioavailability and potent anti-proliferative activity against a broad range of cancer cell lines (with a mean IC50 of 220 nmol/L), including many non-small cell lung cancer (NSCLC) cell lines which are resistant to standard-of-care (SOC) agents. In both laboratory and animal testing, CUDC-305 demonstrated high potency in vitro and/or in vivo across a wide range of cancers. Most notably, Curis scientists observed complete tumor regression following oral administration of CUDC-305 in a mouse xenograft model of acute myelogenous leukemia (AML). Tumor regression has also been observed after treatment of CUDC-305 in mouse xenograft models of breast, non-small cell lung, gastric cancer and glioblastoma brain cancers. In this preclinical testing, the compound also demonstrated an ability to effectively cross the blood brain barrier, and demonstrated an ability to extend survival in an intracranial glioblastoma model. Early stage toxicity studies suggest that CUDC-305 appears to have a better therapeutic window than several leading Hsp90 inhibitors in clinical development.