Tumor-specific anti-angiogenic anti-CD70-FGF/VEGF-trap fusion antibodies for renal cancer therapy

项目总结 肾细胞癌(RCC)是一种发病率呈上升趋势的致命性疾病。它被归类为各种 亚型，其中透明细胞肾癌(CcRCC)约占所有肾癌肿瘤的85%。当前靶向分子 包括酪氨酸激酶抑制剂(TKI)在内的策略已经导致无进展存活率增加一倍 CcRCC患者的总存活率显著提高。尽管治疗取得了进展，但完全和 仅在少数情况下注意到了持久的反应。晚期癌症治疗方法的前景 近年来，由于在发展方面取得了重大进展，RCC迅速扩张 免疫治疗药物。VEGFR靶向和免疫疗法的结合已经显示出显著的意义 临床前景看好，并开启了治愈这种致命疾病的可能性。然而，这样的疗法也有 产生了从中度到不良的额外毒性，需要中断或减少剂量， 从而限制了疗效。另一个限制VEGFR靶向治疗晚期肺癌成功的因素 CcRCC，是均匀发展的阻力。多项研究揭示了成纤维细胞的关键作用 生长因子-2(FGF2)在晚期肾细胞癌耐药中的作用 用抗血管内皮生长因子/血管内皮生长因子2抗体作为抗血管内皮生长因子受体的试剂。因此，我们第一次设计了， 一类新型的双陷阱多肽(F/V陷阱)，可以阻断两条生物上不同的促血管生成途径， VEGFR和FGFR依赖，对肾细胞癌的进展至关重要。将我们的F/V陷阱与抗-HBs Fab片段融合 在CD70抗体的基础上，我们研制了一种新型的三特异性抗CD70-FGF/VEGFTrap融合抗体(F/V-Trap FA)。 这种抗体确实同时与ccRCC中特异表达的配体CD70结合，并中和两者， 血管内皮生长因子-A和成纤维细胞生长因子2。预计通过中和FGF2，一种关键的替代促血管生成细胞因子， F/V-Trap FA可防止或至少显著延缓对抗血管内皮生长因子/血管内皮生长因子受体的耐药性的发展 晚期肾细胞癌的治疗。重要的是，肿瘤内血管内皮生长因子和成纤维细胞生长因子家族的缺失 F/V-Trap FA有望克服靶外抑制血管内皮生长因子/血管内皮生长因子受体所产生的副作用 全身性抗血管生成方法。拟议的研究将检验这样一种假设，即新的双特异性F/V- 与现有的血管内皮生长因子中和剂相比，TRAP FA有两个主要优势。通过靶向成纤维细胞生长因子/血管内皮生长因子陷阱 对于肿瘤，它将：(I)实现更高的肿瘤内FGF/VEGF Trap浓度；(Ii)克服FGF2- 中晚期肾细胞癌患者对常规抗血管生成治疗的耐受性；和(Iii)限制 系统性抗血管内皮细胞生长因子方法中非靶点VEGFR抑制所产生的副作用。测试我们的 为了验证F/V-Trap FA的治疗价值，我们提出了以下具体目标：(1) 新型F/V-Trap FA衍生物的研制、鉴定及性质研究 (2)用抗血管内皮生长因子受体TKI-抗体检测F/V-Trap FA的体内抗血管生成作用。 肾癌耐药的PDX小鼠模型。

PROJECT SUMMARY Renal cell carcinoma (RCC) is a lethal disease whose incidence is on the rise. It is categorized into various subtypes, with clear cell RCC (ccRCC) representing about 85% of all RCC tumors. Current targeted molecular strategies, including tyrosine kinase inhibitors (TKIs), have resulted in a doubling of progression-free survival and significant gains in overall survival in ccRCC patients. Despite the therapeutic progress, complete and durable responses have been noted in only a few cases. The landscape of therapeutic approaches for advanced RCC has expanded rapidly in recent years as a result of significant progress in the development of immunotherapeutic drugs. The combination of VEGFR-targeting and immunotherapies have shown significant clinical promise and opened the possibility of a cure for this lethal disease. However, such therapies have also conferred additional toxicities ranging from moderate to adverse, requiring dose interruptions or reductions, thereby limiting the efficacy. Another factor, limiting the success of VEGFR-targeting therapy of advanced ccRCC, is the resistance which uniformly develops. Multiple studies have revealed the key role of fibroblast growth factor-2 (FGF2) in the development of resistance in advanced ccRCC, irrespective of whether TKIs or anti-VEGF/VEGFR2 antibodies were used as anti-VEGFR agents. Therefore, we have designed for the first time, a novel class of dual-trap peptides (F/V traps), to block two biologically distinct pro-angiogenic pathways, VEGFR- and FGFR-dependent, critical for ccRCC progression. By fusion of our F/V trap to Fab fragment of anti- CD70 antibody, we have developed a new tri-specific anti-CD70-FGF/VEGF Trap fusion antibody (F/V-trap FA). This antibody does simultaneously bind CD70, a ligand, specifically expressed in ccRCC, and neutralize both, VEGF-A and FGF2 cytokines. It is expected that by neutralizing FGF2, a key alternative pro-angiogenic cytokine, F/V-trap FA will prevent or at least significantly delay the development of resistance to anti-VEGF/VEGFR therapy in advanced ccRCC. Importantly, the intra-tumoral depletion of VEGF- and FGF- cytokine families by F/V-trap FA is anticipated to overcome side-effects arising from off-target VEGF/VEGFR inhibition seen with systemic anti-angiogenic approaches. The proposed studies will test the hypothesis that novel bi-specific F/V- trap FA have two major advantages over existing VEGF-neutralizing agents. By targeting the FGF/VEGF trap to tumors, it will: (i) achieve higher intra-tumoral concentrations of the FGF/VEGF Trap; (ii) overcome FGF2- mediated development of resistance to conventional anti-angiogenic therapy in advanced ccRCC; and (iii) limit side-effects arising from off-target VEGFR inhibition seen with systemic anti-VEGF approaches. To test our hypothesis and to validate the therapeutic value of F/V-trap FA, we propose the following Specific Aims: (1) Development, identification and characterization of the leading F/V-trap FA derivative with superior FGF/VEGF neutralizing activity; (2) To examine the anti-angiogenic efficacy of F/V-trap FA in vivo using anti-VEGFR TKI- resistant PDX mouse models of RCC.