Ibrutinib is an orally bioavailable Bruton's tyrosine kinase (BTK) inhibitor indicated for the treatment of mantle cell lymphoma (MCL) patients that previously received at least one therapy. The drug was jointly developed by Janssen Biotech and Pharmacyclics. Ibrutinib selectively binds to Cys-481 residue in the allosteric inhibitory segment of BTK (TK/SH1 domain), and irreversibly blocks its enzymatic activity thus preventing B-cell activation and signaling, totally blocking the B-cell receptor and cytokine receptor pathways. This leads to an inhibition of the growth of malignant B cells that overexpress BTK. Apart from mantle cell lymphoma Ibrutinib is approved for the treatment of chronic lymphocytic leukemia and Waldenstrom Macroglobulinemia.

Afatinib is a anilino-quinazoline derivative and irreversible antagonist of the receptor tyrosine kinase epidermal growth factor receptor family, with antineoplastic activity. Afatinib selectively and covalently binds to and inhibits the epidermal growth factor receptors 1 (ErbB1; EGFR), 2 (ErbB2; HER2), and 4 (ErbB4; HER4), and certain EGFR mutants, including those caused by EGFR exon 19 deletion mutations or exon 21 (L858R) mutations. This may result in the inhibition of tumor growth and angiogenesis in tumor cells overexpressing these kinases. Additionally, afatinib inhibits the EGFR T790M gatekeeper mutation which is resistant to treatment with first-generation EGFR inhibitors. EGFR, HER2 and HER4 are RTKs that belong to the EGFR superfamily; they play major roles in both tumor cell proliferation and tumor vascularization and are overexpressed in many cancer cell types. Afatinib is a substrate and an inhibitor of P-gp and of the transporter BCRP. Co-administration of P-gp inhibitors can increase afatinib exposure while co-administration of chronic P­gp inducers can decrease afatinib exposure.

Tofacitinib is an orally available inhibitor of Janus kinases (JAK), with immunomodulatory and anti-inflammatory activities. Upon administration, tofacitinib binds to JAK and prevents the activation of the JAK-signal transducers and activators of transcription (STAT) signaling pathway. This may decrease the production of pro-inflammatory cytokines, such as interleukin (IL)-6, -7, -15, -21, interferon-alpha and -beta, and may prevent both an inflammatory response and the inflammation-induced damage caused by certain immunological diseases. JAK kinases are intracellular enzymes involved in signaling pathways affecting hematopoiesis, immunity and inflammation. Tofacitinib was discovered and developed by the National Institutes of Health and Pfizer. Besides rheumatoid arthritis, tofacitinib has also been studied in clinical trials for the prevention of organ transplant rejection, and the treatment of psoriasis and ulcerative colitis. Patients treated with tofacitinib (XELJANZ) are at increased risk for developing serious infections that may lead to hospitalization or death and adverse reactions. Most patients who developed these infections were taking concomitant immunosuppressants such as methotrexate or corticosteroids.

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.

Cabozantinib (development code name XL184; marketed under the trade name Cometriq) is an orally bioavailable, small molecule receptor tyrosine kinase (RTK) inhibitor with potential antineoplastic activity. Cabozantinib strongly binds to and inhibits several RTKs, which are often overexpressed in a variety of cancer cell types, including hepatocyte growth factor receptor (MET), RET (rearranged during transfection), vascular endothelial growth factor receptor types 1 (VEGFR-1), 2 (VEGFR-2), and 3 (VEGFR-3), mast/stem cell growth factor (KIT), FMS-like tyrosine kinase 3 (FLT-3), TIE-2 (TEK tyrosine kinase, endothelial), tropomyosin-related kinase B (TRKB) and AXL. This may result in an inhibition of both tumor growth and angiogenesis, and eventually lead to tumor regression. Cabozantinib was granted orphan drug status by the U.S. Food and Drug Administration (FDA) in January 2011. It is currently undergoing clinical trials for the treatment of prostate, bladder, ovarian, brain, melanoma, breast, non-small cell lung, pancreatic, hepatocellular and kidney cancers.

Crizotinib (trade name Xalkori, Pfizer, Inc.) is an anti cancer drug approved for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors are anaplastic lymphoma kinase (ALK)-positive as detected by an FDA-approved test. Crizotinib is an inhibitor of receptor tyrosine kinases including ALK, Hepatocyte Growth Factor Receptor (HGFR, c-Met), ROS1 (c-ros), and Recepteur d’Origine Nantais (RON). Common adverse reactions in clinical trials with crizotinib, occurring at an incidence of 25% or higher, included visual disorders, nausea, diarrhea, vomiting, constipation, edema, elevated transaminases, and fatigue. Crizotinib is currently under investigational study for use in treatment of Uveal Melanoma.

Ruxolitinib (trade names Jakafi and Jakavi, by Incyte Pharmaceuticals and Novartis) is a drug for the treatment of intermediate or high-risk myelofibrosis, a type of myeloproliferative disorder that affects the bone marrow. It is also being investigated for the treatment of other types of cancer (such as lymphomas and pancreatic cancer), for polycythemia vera, for plaque psoriasis, and for alopecia areata. Myelofibrosis (MF) is a myeloproliferative neoplasm (MPN) known to be associated with dysregulated JAK1 and JAK2 signaling. Ruxolitinib is a Janus-associated kinase (JAK) inhibitor with potential antineoplastic and immunomodulating activities. Ruxolitinib specifically binds to and inhibits protein tyrosine kinases JAK 1 and 2, which may lead to a reduction in inflammation and an inhibition of cellular proliferation. The JAK-STAT (signal transducer and activator of transcription) pathway plays a key role in the signaling of many cytokines and growth factors and is involved in cellular proliferation, growth, hematopoiesis, and the immune response; JAK kinases may be upregulated in inflammatory diseases, myeloproliferative disorders, and various malignancies. In a mouse model of JAK2V617F-positive MPN, ruxolitinib prevented splenomegaly, preferentially decreased JAK2V617F mutant cells in the spleen and decreased circulating inflammatory cytokines (eg, TNF-α, IL-6). Ruxolitinib was initially synthesized at Incyte Corporation that acquired the rights to develop and commercialize the drug in US. Incyte amended its Collaboration and License Agreement with Novartis, granting Novartis exclusive research, development and commercialization rights for ruxolitinib outside the U.S.

Vandetanib, 4-anilinoquinazoline, is an anti-cancer drug that with the potential for use in a broad range of tumour types. In 2011 vandetanib (trade name Caprelsa) was approved by the FDA to treat nonresectable, locally advanced, or metastatic medullary thyroid cancer in adult patients. In vitro studies have shown that vandetanib inhibits the tyrosine kinase activity of the EGFR and VEGFR families, RET, BRK, TIE2, and members of the EPH receptor and Src kinase families. These receptor tyrosine kinases are involved in both normal cellular function and pathologic processes such as oncogenesis, metastasis, tumor angiogenesis, and maintenance of the tumor microenvironment. Vandetanib was shown to inhibit epidermal growth factor (EGF)-stimulated receptor tyrosine kinase phosphorylation in tumor cells and endothelial cells and VEGF-stimulated tyrosine kinase phosphorylation in endothelial cells. Vandetanib administration reduced tumor cell-induced angiogenesis, tumor vessel permeability, and inhibited tumor growth and metastasis in mouse models of cancer.

Pazopanib (VOTRIENT) is an orally bioavailable multi-targeted tyrosine kinase receptor inhibitor. Pazopanib inhibits vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, VEGFR-3, platelet-derived growth factor receptor (PDGFR)-α and -β, fibroblast growth factor receptor (FGFR) -1 and -3, cytokine receptor (Kit), interleukin-2 receptor inducible T-cell kinase (Itk), leukocyte-specific protein tyrosine kinase (Lck), and transmembrane glycoprotein receptor tyrosine kinase (c-Fms). In an vitro study, pazopanib exerted anti-tumor effect through mechanisms including the Raf-MAPK/ERK (MEK)-extracellular signal-regulated kinase (ERK) pathway. It has good oral exposure and inhibits angiogenesis and tumor growth in mice. Pazopanib (VOTRIENT) was developed by GlaxoSmithKline for the treatment of solid tumours and age-related macular degeneration. However, Novartis acquired all the rights to the drug from GlaxoSmithKline. Pazopanib (VOTRIENT) is indicated for the treatment of patients with advanced renal cell carcinoma and advanced soft tissue sarcoma.

Lapatinib is a small molecule and a member of the 4-anilinoquinazoline class of kinase inhibitors. It is present as the monohydrate of the ditosylate salt (trade name TYKERB). Lapatinib is dual inhibitor of the EGFR (epidermal growth factor receptor; also called HER1 or ErbB1) and HER2 receptor tyrosine kinases. Lapatinib was developed by GlaxoSmithKline, however, Novartis subsequently acquired all the rights to the drug from GlaxoSmithKline. TYKERB is indicated in combination therapy for the treatment of metastatic breast cancer that overexpresses the HER2 receptor.