Corresponding Author: Hidenori Fujita, Tsukuba Research Center, Taiho Pharmaceutical Co., Ltd., 3 Okubo, Tsukuba, Ibaraki 300-2611, Japan.
Mol Cancer Ther. 2013 Dec;12(12):2685-96. doi: 10.1158/1535-7163.MCT-13-0459. Epub 2013 Oct 18.
VEGF receptor (VEGFR) signaling plays a key role in tumor angiogenesis. Although some VEGFR signal-targeted drugs have been approved for clinical use, their utility is limited by associated toxicities or resistance to such therapy. To overcome these limitations, we developed TAS-115, a novel VEGFR and hepatocyte growth factor receptor (MET)-targeted kinase inhibitor with an improved safety profile. TAS-115 inhibited the kinase activity of both VEGFR2 and MET and their signal-dependent cell growth as strongly as other known VEGFR or MET inhibitors. On the other hand, kinase selectivity of TAS-115 was more specific than that of sunitinib and TAS-115 produced relatively weak inhibition of growth (GI50 > 10 μmol/L) in VEGFR signal- or MET signal-independent cells. Furthermore, TAS-115 induced less damage in various normal cells than did other VEGFR inhibitors. These data suggest that TAS-115 is extremely selective and specific, at least in vitro. In in vivo studies, TAS-115 completely suppressed the progression of MET-inactivated tumor by blocking angiogenesis without toxicity when given every day for 6 weeks, even at a serum-saturating dose of TAS-115. The marked selectivity of TAS-115 for kinases and targeted cells was associated with improved tolerability and contributed to the ability to sustain treatment without dose reduction or a washout period. Furthermore, TAS-115 induced marked tumor shrinkage and prolonged survival in MET-amplified human cancer-bearing mice. These data suggest that TAS-115 is a unique VEGFR/MET-targeted inhibitor with improved antitumor efficacy and decreased toxicity.
血管内皮生长因子受体(VEGFR)信号在肿瘤血管生成中起着关键作用。尽管一些 VEGFR 信号靶向药物已被批准用于临床应用,但由于相关毒性或对这种治疗的耐药性,其应用受到限制。为了克服这些限制,我们开发了 TAS-115,一种新型的 VEGFR 和肝细胞生长因子受体(MET)靶向激酶抑制剂,具有改善的安全性。TAS-115 强烈抑制 VEGFR2 和 MET 的激酶活性及其信号依赖性细胞生长,与其他已知的 VEGFR 或 MET 抑制剂相当。另一方面,TAS-115 的激酶选择性比舒尼替尼更特异,TAS-115 对 VEGFR 信号或 MET 信号不依赖的细胞生长的抑制作用较弱(GI50 > 10 μmol/L)。此外,TAS-115 对各种正常细胞的损伤比其他 VEGFR 抑制剂小。这些数据表明,TAS-115 至少在体外具有极高的选择性和特异性。在体内研究中,TAS-115 通过阻断血管生成,每天给药 6 周,即使在 TAS-115 血清饱和剂量下,也完全抑制了 MET 失活肿瘤的进展,而无毒性。TAS-115 对激酶和靶细胞的显著选择性与可耐受性的提高有关,并有助于在不减少剂量或不洗脱的情况下维持治疗。此外,TAS-115 诱导 MET 扩增的人源肿瘤荷瘤小鼠的肿瘤显著缩小和生存延长。这些数据表明,TAS-115 是一种具有改善的抗肿瘤疗效和降低毒性的独特的 VEGFR/MET 靶向抑制剂。