Imatinib (GLEEVEC®) is a tyrosine kinase inhibitor and antineoplastic agent that inhibits the BCR-ABL tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in chronic myeloid leukaemia (CML). It inhibits proliferation and induces apoptosis in BCR-ABL positive cell lines as well as fresh leukemic cells from Philadelphia chromosome positive CML. Imatinib (GLEEVEC®) inhibits colony formation in assays using ex vivo peripheral blood and bone marrow samples from CML patients. It is also an inhibitor of the receptor tyrosine kinases for platelet-derived growth factor (PDGF) and stem cell factor (SCF), c-kit, and inhibits PDGF- and SCF-mediated cellular events. In vitro, imatinib (GLEEVEC®) inhibits proliferation and induces apoptosis in gastrointestinal stromal tumor (GIST) cells, which express an activating c-kit mutation.

Ponatinib (trade name Iclusig, previously AP24534) is developed by ARIAD Pharmaceuticals for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome–positive (Ph ) acute lymphoblastic leukemia (ALL). Ponatinib has been designed to be effective against these types of tumors. The United States Food and Drug Administration approved the drug as a candidate in 2012, but temporarily suspended sales on 31 October 2013 because of "the risk of life-threatening blood clots and severe narrowing of blood vessels". This suspension was partially lifted on Dec. 20, 2013 with ponatinib being issued revised prescribing information, a new "Black Box Warning" and a "Risk Evaluation and Mitigation Strategy" in place to better evaluate the risks and benefits of using the drug. Ponatinib is an orally bioavailable multitargeted receptor tyrosine kinase (RTK) inhibitor with potential antiangiogenic and antineoplastic activities. Ponatinib inhibits unmutated and all mutated forms of Bcr-Abl, including T315I, the highly drug therapy-resistant missense mutation of Bcr-Abl. This agent also inhibits other tyrosine kinases including those associated with vascular endothelial growth factor receptors (VEGFRs) and fibroblast growth factor receptors (FGFRs); in addition, it inhibits the tyrosine kinase receptor TIE2 and FMS-related tyrosine kinase receptor-3 (Flt3). RTK inhibition by ponatinib may result in the inhibition of cellular proliferation and angiogenesis and may induce cell death. Bcr-Abl is a fusion tyrosine kinase encoded by the Philadelphia chromosome.

Axitinib (trade name Inlyta) is a small molecule tyrosine kinase inhibitor developed by Pfizer. It has been shown to significantly inhibit growth of breast cancer in animal (xenograft) models and has shown partial responses in clinical trials with renal cell carcinoma (RCC) and several other tumour types. Axitinib has been shown to inhibit receptor tyrosine kinases including vascular endothelial growth factor receptors (VEGFR)-1, VEGFR-2, and VEGFR-3 at therapeutic plasma concentrations. These receptors are implicated in pathologic angiogenesis, tumor growth, and cancer progression. VEGF-mediated endothelial cell proliferation and survival were inhibited by axitinib in vitro and in mouse models. It was approved by the U.S. Food and Drug Administration.

Nilotinib (AMN107, trade name Tasigna) is a kinase inhibitor indicated for the treatment of chronic phase and accelerated phase Philadelphia chromosome-positive chronic myelogenous leukemia (CML) in adult patients resistant to or intolerant to prior therapy that included imatinib. Nilotinib is an inhibitor of the Bcr-Abl kinase. Nilotinib binds to and stabilizes the inactive conformation of the kinase domain of Abl protein. In vitro, nilotinib inhibited Bcr-Abl mediated proliferation of murine leukemic cell lines and human cell lines derived from Ph+ CML patients. Under the conditions of the assays, nilotinib was able to overcome imatinib resistance resulting from Bcr-Abl kinase mutations, in 32 out of 33 mutations tested. In vivo, nilotinib reduced the tumor size in a murine Bcr-Abl xenograft model. Nilotinib inhibited the autophosphorylation of the following kinases at IC50 values as indicated: Bcr-Abl (20-60 nM), PDGFR (69 nM) and c-Kit (210 nM). Nilotinib is currently being trialed in people with Parkinson's disease, as it appears to be able to halt progression of the disease and even improve their symptoms. The drug also has a number of adverse effects typical of anti-cancer drugs: a headache, fatigue, gastrointestinal problems such as nausea, vomiting, diarrhea and constipation, muscle and joint pain, rash and other skin conditions, flu-like symptoms, and reduced blood cell count. Less typical side effects are those of the cardiovascular system, such as hypertension (high blood pressure), various types of arrhythmia, and prolonged QT interval. Interaction of nilotinib with OATP1B1 and OATP1B3 may alter its hepatic disposition and can lead to transporter mediated drug-drug interactions. Nilotinib is an inhibitor of OATP-1B1 transporter but not for OATP-1B3. Main metabolic pathways identified in healthy subjects are oxidation and hydroxylation. Nilotinib is the main circulating component in the serum. None of the metabolites contributes significantly to the pharmacological activity of nilotinib.

Temsirolimus is an intravenous drug for the treatment of renal cell carcinoma (RCC), developed by Wyeth Pharmaceuticals and approved by the FDA in late May 2007, and was also approved by the European Medicines Agency (EMEA) on November 2007. It is a derivative of sirolimus and is sold as Torisel. Temsirolimus is an inhibitor of mTOR (mammalian target of rapamycin). Temsirolimus binds to an intracellular protein (FKBP-12), and the protein-drug complex inhibits the activity of mTOR that controls cell division. Inhibition of mTOR activity resulted in a G1 growth arrest in treated tumor cells. When mTOR was inhibited, its ability to phosphorylate p70S6k and S6 ribosomal protein, which are downstream of mTOR in the PI3 kinase/AKT pathway was blocked. In in vitro studies using renal cell carcinoma cell lines, temsirolimus inhibited the activity of mTOR and resulted in reduced levels of the hypoxia-inducible factors HIF-1 and HIF-2 alpha, and the vascular endothelial growth factor.

Dasatinib [BMS 354825] is an orally active, small molecule, dual inhibitor of both SRC and ABL kinases that is under development with Bristol-Myers Squibb for the treatment of patients with chronic myelogenous leukaemia (CML) and imatinib-acquired resistance/intolerance. It’s used for the treatment of adults with chronic, accelerated, or myeloid or lymphoid blast phase chronic myeloid leukemia with resistance or intolerance to prior therapy. Also indicated for the treatment of adults with Philadelphia chromosome-positive acute lymphoblastic leukemia with resistance or intolerance to prior therapy. While imatinib remains a frontline therapy for CML, patients with advanced disease frequently develop resistance to imatinib therapy through multiple mechanisms. Dasatinib is also undergoing preclinical evaluation for its potential as a therapy against multiple myeloma. Bristol-Myers Squibb has a composition-of-matter patent covering this research approach that will expire in 2020. Dasatinib, at nanomolar concentrations, inhibits the following kinases: BCR-ABL, SRC family (SRC, LCK, YES, FYN), c-KIT, EPHA2, and PDGFRβ. Based on modeling studies, dasatinib is predicted to bind to multiple conformations of the ABL kinase.

GZD824 is a novel orally bioavailable Bcr-Abl inhibitor for Bcr-Abl(WT) and Bcr-Abl(T315I) with IC50 of 0.34 nM and 0.68 nM, respectively. In vivo efficacy studies in mouse xenograft or allograft models of human leukemia demonstrated that GZD824 successfully suppressed the growth of tumors driven by native Bcr-Abl, Bcr-Abl T315I, Bcr-Abl G250E, Bcr-Abl Q252H, Bcr-Abl E255K and Bcr-Abl F317L. GZD824 also provided a significant survival benefit leukemia model mice allografted with luciferase-expressing Ba/F3 cells driven by the mutant Bcr-Abl T315I kinase. The potential for compound GZD824 to overcome all of the Bcr-Abl mutations that result in clinically acquired resistance to imatinib indicates that this novel Bcr-Abl inhibitor is a promising lead candidate for further development. GZD824 has also being shown to suppresses pre-B ALL cells through inhibition of the SRC kinase and PI3K/AKT pathways and may be a potential therapeutic agent for the management of pre-B ALL.

Rebastinib (DCC-20) is a TIE2 kinase inhibitor currently in Phase 1 clinical development to treat breast cancer and Chronic Myeloid Leukemia. Rebastinib potently inhibited TIE2 kinase in cellular assays and blocked primary tumor growth by 75% as a single agent and by 90% in combination with the standard chemotherapeutic agent paclitaxel. Furthermore, rebastinib therapy significantly reduced the presence of tumor-promoting macrophages in tumor biopsies by 80%. This blockade of tumor macrophages correlated with inhibition of breast cancer lung metastases.

AT-9283 was being developed by Astex Pharmaceuticals as a treatment for cancer and myelofibrosis. AT-9283 is an inhibitor of mitosis (cell division) and is the second most progressed drug candidate in the Astex portfolio of novel molecularly targeted cancer drugs. All of Astex’s current products have been discovered internally using its proprietary drug discovery approach. AT9283 is a potent inhibitor of the Aurora A and B kinases and has been shown to arrest tumour growth in a range of tumour models. Aurora kinases play a key role in mitotic checkpoint control in cell division. Both Aurora A and B are over-expressed in many human tumours and are believed to be excellent targets for anti-cancer therapy.