PF-3758309 was developed as an ATP-competitive inhibitor of PAK4. In cells, PF-3758309 inhibits phosphorylation of the PAK4 substrate GEF-H1 (IC50 = 1.3 nM) and anchorage-independent growth of a panel of tumor cell lines (IC50 = 4.7 nM). PF-3758309 blocks the growth of multiple human tumor xenografts, with a plasma EC50 value of 0.4 nM in the most sensitive model. PF-3758309 is antiproliferative and induces apoptosis in an HCT116 tumor model.

Pevonedistat (MLN4924), discovered by Millennium, is a small molecule inhibitor of the NEDD8-Activating Enzyme (NAE), a key component of the protein homeostasis pathway. MLN4924 is a mechanism-based inhibitor of NAE and creates a covalent NEDD8-MLN4924 adduct catalyzed by the enzyme. The NEDD8-MLN4924 adduct resembles NEDD8 adenylate, the first intermediate in the NAE reaction cycle, but cannot be further utilized in subsequent intraenzyme reactions. The stability of the NEDD8-MLN4924 adduct within the NAE active site blocks enzyme activity, thereby accounting for the potent inhibition of the NEDD8 pathway by MLN4924. This drug is in phase II clinical trial for the treatment acute myeloid leukemia, chronic myelomonocytic leukemia and myelodysplastic syndromes. In addition in phase I for treatment acute lymphoblastic leukemia. The ability of MLN4924 to cross the blood-brain barrier, its low toxicity, and clinical efficacy in other cancers suggests that this drug is an attractive treatment against glioblastomas.

ZSTK474 is a new PI3K inhibitor with strong antitumor activity against human cancer xenografts without toxic effects in critical organs. Specifically, ZSTK474 is an ATP-competitive inhibitor of class I phosphatidylinositol 3 kinase isoforms. ZSTK474 blocks VEGF-induced cell migration and the tube formation in human umbilical vein endothelial cells (HUVECs), and inhibits the expression of HIF-1α and secretion of VEGF in RXF-631L cells, exhibiting potent in vitro antiangiogenic activity. ZSTK474 demonstrated prophylactic efficacy in a rat model of rheumatoid arthritis (RA) through inhibition of T cell and FLS functions.

Veribulin is a novel microtubule destabilizer that both functions as a potent cytotoxin and acts as a vascular disrupting agent (VDA). It binds to the same (or nearby) sites on β-tubulin as colchicine. It is capable of evading multidrug resistance pumps and, thus, achieves high CNS concentrations. It is efficacious in multiple xenograft models without CNS toxicity. Veribulin had previously demonstrated pre-clinical and clinical activity in multiple tumor types. Veribulin is in phase II clinical trial for the treatment of Glioblastoma and Malignant melanoma.

AstraZeneca was developing AZD-8055, an orally active mTORC1/mTORC2 inhibitor, for the treatment of advanced solid tumours. AZD-8055 is an ATP-competitive mTORC1/2 inhibitor that exhibits immunosuppressive and anticancer chemotherapeutic activities. AZD-8055 promotes antibody class switching in B cells at low doses and decreases B cell proliferation and differentiation at high doses. In vivo, this compound suppresses CC4 and CD8 T cell proliferation, increasing survival among MHC-mismatched heart transplant recipients. In vitro, AZD-8055 decreases viability of brain tumor cells; in vivo, it inhibits tumor growth. AZD-8055 had been in phase I trials by AstraZeneca for the treatment of malignant gliomas and solid tumours. However, this research has been discontinued.

Ganetespib (formerly called STA-9090) is a novel, injectable resorcinolic triazolone small molecule inhibitor of Hsp90, developed by Synta Pharmaceuticals. Ganetespib inhibits the growth of many tumor types in vitro and in vivo including AML, ALL, CML, NHL, neuroblastoma, Ewing sarcoma, rhabdoid cancer, rhabdomyosarcoma, melanoma, and carcinomas of the breast, lung, prostate, bladder and colon7-10,14-27. Ganetespib has being studied in multiple adult oncology indications. The 50% inhibitory concentrations (IC50) for Ganetespib against malignant mast cell lines are 10-50 times lower than that for 17-AAG, indicating that triazolone class of HSP90 inhibitors likely exhibits greater potency than geldanamycin based inhibitors. Ganetespib inhibits MG63 cell lines with IC50 of 43 nM. Ganetespib binds to the ATP-binding domain at the N-terminus of Hsp90 and serves as a potent Hsp90 inhibitor by causing degradation of multiple oncogenic Hsp90 client proteins including HER2/neu, mutated EGFR, Akt, c-Kit, IGF-1R, PDGFRα, Jak1, Jak2, STAT3, STAT5, HIF-1α, CDC2 and c-Met as well as Wilms' tumor 1. Ganetespib, at low nanomolar concentrations, potently arrests cell proliferation and induces apoptosis in a wide variety of human cancer cell lines, including many receptor tyrosine kinase inhibitor- and tanespimycin-resistant cell lines. Ganetespib exhibits potent cytotoxicity in a range of solid and hematologic tumor cell lines, including those that express mutated kinases that confer resistance to small-molecule tyrosine kinase inhibitors. Ganetespib has been studied in 5 completed Synta-sponsored clinical trials (Studies 9090-02, 9090-03, 9090-04, 9090-05, and 9090-07) and 3 completed Synta-sponsored studies in normal healthy volunteers (9090-12, 9090-13, and 9090-15). Ganetespib is currently being studied in 6 Synta-sponsored clinical trials. Studies include: one Phase 1 study, three Phase 2 studies, one Phase 2b study, and one Phase 3 study. Ganetespib is also being studied in 24 Investigator Sponsored Trials (ISTs)

Barasertib (AZD1152) is a dihydrogen phosphate prodrug of a pyrazoloquinazoline Aurora kinase inhibitor [AZD1152–hydroxyquinazoline pyrazol anilide (HQPA)] and is converted rapidly to the active AZD1152-HQPA in plasma. AstraZeneca was developing the aurora kinase inhibitor, barasertib (AZD 1152) as a therapeutic for cancer. AZD1152-HQPA is a highly potent and selective inhibitor of Aurora B (Ki, 0.36nmol/L) compared with Aurora A (Ki, 1,369nmol/L) and has a high specificity versus a panel of 50 other kinases. Consistent with inhibition of Aurora B kinase, addition of AZD1152-HQPA to tumour cells in vitro induces chromosome misalignment, prevents cell division, and consequently reduces cell viability and induces apoptosis. Barasertib (AZD1152) potently inhibited the growth of human colon, lung, and haematologic tumour xenografts (mean tumour growth inhibition range, 55% to ≥100%; P < 0.05) in immunodeficient mice. Detailed pharmacodynamic analysis in colorectal SW620 tumour-bearing athymic rats treated i.v. with Barasertib (AZD1152) revealed a temporal sequence of phenotypic events in tumours: transient suppression of histone H3 phosphorylation followed by accumulation of 4N DNA in cells (2.4-fold higher compared with controls) and then an increased proportion of polyploid cells (>4N DNA, 2.3-fold higher compared with controls). Histologic analysis showed aberrant cell division that was concurrent with an increase in apoptosis in AZD1152-treated tumours. Bone marrow analyses revealed transient myelosuppression with the drug that was fully reversible following cessation of Barasertib (AZD1152) treatment. Barasertib (AZD1152) was in phase III for the treatment of Acute myeloid leukaemia, but later these studies were discontinued.

Brivanib is a pyrrolotriazine-based compound and an inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) with potential antineoplastic activity. It specifically targets and strongly binds to human VEGFR-2, a tyrosine kinase receptor and pro-angiogenic growth factor expressed almost exclusively on vascular endothelial cells. Blockade of VEGFR-2 by this agent may lead to an inhibition of VEGF-stimulated endothelial cell migration and proliferation, thereby inhibiting tumor angiogenesis. Brivanib has a moderate potency compared to VEGFR-2 against VEGFR-1 and FGFR-1 as well. Brivanib is suggested to be efficient in treatment of hepatocellular carcinoma (HCC). As first-line and as second-line therapy brivanib demonstrated promising antitumor activity and a manageable safety profile in patients with advanced, unresectable HCC in phase II clinical trials. On 3 march 2011, orphan designation was granted by the European Commission to Bristol-Myers Squibb for brivanib alaninate for the treatment of hepatocellular carcinoma.[

AZD1775 selectively targets and inhibits WEE1, a tyrosine kinase that phosphorylates cyclin-dependent kinase 1 (CDK1, CDC2) to inactivate the CDC2/cyclin B complex. Inhibition of WEE1 activity prevents the phosphorylation of CDC2 and impairs the G2 DNA damage checkpoint. This may lead to apoptosis upon treatment with DNA damaging chemotherapeutic agents. Current ongoing trials of AZD1775 include monotherapy and combination therapy with certain DNA damaging agents in solid tumors, ovarian tumors, gynaecological cancer, non-small cell lung cancer. AZD1775 is genotoxic, which is considered to be a result of its mechanism of action. Common serious adverse events (with chemotherapy) include: febrile neutropenia, neutropenia, thrombocytopenia.

GSK1070916 is a novel, azaindole derived, reversible and ATP-competitive inhibitor of the Aurora B/C kinases. GSK1070916 inhibits the proliferation of tumor cells and has antitumor effects in 10 human tumor xenograft models including breast, colon, lung, and two leukemia models. Nemucore Medical Innovations and Cancer Research UK are developing NMI 900 (previously GSK 1070916) for the intravenous treatment of cancer. The product was originally developed by GlaxoSmithKline. A phase I/II trial in patients with solid tumours has been completed in the UK. Phase II development in ovarian cancer is underway in the US.