Sun Qiaoling, Zhou Jinghong, Zhang Zheng, Guo Mingchuan, Liang Junqing, Zhou Feng, Long Jingwen, Zhang Wei, Yin Fang, Cai Huaqing, Yang Haibin, Zhang Weihan, Gu Yi, Ni Liang, Sai Yang, Cui Yumin, Zhang Meifang, Hong Minhua, Sun Junen, Yang Zheng, Qing Weiguo, Su Weiguo, Ren Yongxin
a Department of Oncology; Hutchison MediPharma Limited ; Shanghai , China ;
Cancer Biol Ther. 2014;15(12):1635-45. doi: 10.4161/15384047.2014.964087.
VEGF/VEGFR signal axis has been proven to be an important target for development of novel cancer therapies. One challenging aspect in small molecular VEGFR inhibitors is to achieve sustained target inhibition at tolerable doses previously seen only with the long-acting biologics. It would require high potency (low effective drug concentrations) and sufficient drug exposures at tolerated doses so that the drug concentration can be maintained above effective drug concentration for target inhibition within the dosing period. Fruquintinib (HMPL-013) is a small molecule inhibitor with strong potency and high selectivity against VEGFR family currently in Phase II clinical studies. Analysis of Phase I pharmacokinetic data revealed that at the maximum tolerated dose of once daily oral administration fruquintinib achieved complete VEGFR2 suppression (drug concentrations were maintained above that required to produce >85% inhibition of VEGFR2 phosphorylation in mouse) for 24 hours/day. In this article, the preclinical data for fruquintinib will be described, including kinase enzyme activity and selectivity, cellular VEGFR inhibition and VEGFR-driven functional activity, in vivo VEGFR phosphorylation inhibition in the lung tissue in mouse and tumor growth inhibition in a panel of tumor xenograft and patient derive xenograft models in mouse. Pharmacokinetic and target inhibition data are also presented to provide a correlation between target inhibition and tumor growth inhibition.
VEGF/VEGFR信号轴已被证明是新型癌症治疗药物研发的重要靶点。小分子VEGFR抑制剂面临的一个挑战是,要在可耐受剂量下实现持续的靶点抑制,而这在以前只有长效生物制剂才能做到。这需要高效能(低有效药物浓度)以及在可耐受剂量下有足够的药物暴露,以便在给药期间药物浓度能维持在有效药物浓度之上,从而抑制靶点。呋喹替尼(HMPL-013)是一种小分子抑制剂,对VEGFR家族具有强效和高选择性,目前正处于II期临床研究阶段。对I期药代动力学数据的分析表明,在每日一次口服给药的最大耐受剂量下,呋喹替尼可实现VEGFR2的完全抑制(药物浓度维持在小鼠体内产生>85%的VEGFR2磷酸化抑制所需浓度之上),且每天持续24小时。在本文中,将描述呋喹替尼的临床前数据,包括激酶酶活性和选择性、细胞VEGFR抑制和VEGFR驱动的功能活性、小鼠肺组织中的体内VEGFR磷酸化抑制以及一组肿瘤异种移植模型和患者来源的异种移植模型中的肿瘤生长抑制。还将展示药代动力学和靶点抑制数据,以提供靶点抑制与肿瘤生长抑制之间的相关性。