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Almost all cancers show intrinsic and/or evasive resistance to vascular endothelial growth factor ( VEGF) inhibitors by multiple mechanisms. Serum angiopoietin-2 (Ang2) level has been proposed as a potential biomarker of VEGF inhibitor response in several cancers. From these clinical observations, the Ang2 and Tie2 (its receptor) axis has been focused on as a promising target. Here, we show a novel strategy to circumvent the resistance by combining multi-tyrosine kinase inhibitors lenvatinib ( VEGF receptor, fibroblast growth factor receptor, and RET inhibitor) and golvatinib (E7050; c-Met, Tie2, and EphB4 inhibitor). Tie2 identifies a highly pro-angiogenic macrophage subset, Tie2-expressing macrophages ( TEM). Angi-Tie2 and EphB4-EphrinB2 signaling plays critical roles in pericyte-mediated vessel stabilization. In vitro analyses suggested that golvatinib combined with lenvatinib inhibited pericyte-mediated vessel stabilization and TEM differentiation. In thyroid and endometrial cancer models, golvatinib and lenvatinib inhibited pericyte network development and TEM infiltration, resulting in severe perfusion disorder and massive apoptosis. Body weight loss was tolerable, and no macroscopic change was observed. These preclinical studies suggest that modulation of the tumor microenvironment by a strategic and well-tolerated combination of multi-targeting tyrosine kinase inhibitors may sensitize cancer to VEGF inhibitors. [ABSTRACT FROM AUTHOR]

The current standard treatment option for advanced hepatocellular carcinoma (HCC) is sorafenib, but its clinical benefit is modest. In spite of many attempts, few drugs can provide any significant improvement of survival as the first- or second-line therapy of choice in phase III randomized controlled trials. Recently, the subgroup analysis of a phase II randomized controlled trial has shown that tivantinib, a selective MET inhibitor, can significantly improve the overall survival in patients with MET-positive advanced HCC after the failure or intolerance of a prior systemic therapy. These findings enlighten the role of MET inhibitors in the treatment of advanced HCC. In this paper, we review all ongoing and completed clinical trials regarding this topic. As for the first-line therapy of advanced HCC, INC280 and foretinib are being evaluated in 2 phase II single-arm trials; and MSC2156119J and golvatinib plus sorafenib are being compared with sorafenib alone in 2 phase II randomized controlled trials. As for the second-line therapy of advanced HCC, tivantinib and cabozantinib are being compared with placebo in 2 phase III randomized controlled trials.