Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America.
EyePoint Pharmaceuticals, Inc., Watertown, Massachusetts, United States of America.
PLoS One. 2024 Jun 4;19(6):e0304782. doi: 10.1371/journal.pone.0304782. eCollection 2024.
Pathological angiogenesis and vascular instability are observed in diabetic retinopathy (DR), diabetic macular edema (DME), and wet age-related macular degeneration (wAMD). Many receptor tyrosine kinases (RTKs) including vascular endothelial growth factor receptors (VEGFRs) contribute to angiogenesis, whereas the RTK TIE2 is important for vascular stability. Pan-VEGFR tyrosine kinase inhibitors (TKIs) such as vorolanib, sunitinib, and axitinib are of therapeutic interest over current antibody treatments that target only one or two ligands. This study compared the anti-angiogenic potential of these TKIs.
A kinase HotSpot™ assay was conducted to identify TKIs inhibiting RTKs associated with angiogenesis and vascular stability. Half-maximal inhibitory concentration (IC50) for VEGFRs and TIE2 was determined for each TKI. In vitro angiogenesis inhibition was investigated using a human umbilical vein endothelial cell sprouting assay, and in vivo angiogenesis was studied using the chorioallantoic membrane assay. Melanin binding was assessed using a melanin-binding assay. Computer modeling was conducted to understand the TIE2-axitinib complex as well as interactions between vorolanib and VEGFRs.
Vorolanib, sunitinib, and axitinib inhibited RTKs of interest in angiogenesis and exhibited pan-VEGFR inhibition. HotSpot™ assay and TIE2 IC50 values showed that only axitinib potently inhibited TIE2 (up to 89%). All three TKIs effectively inhibited angiogenesis in vitro. In vivo, TKIs were more effective at inhibiting VEGF-induced angiogenesis than the anti-VEGF antibody bevacizumab. Of the three TKIs, only sunitinib bound melanin. TKIs differ in their classification and binding to VEGFRs, which is important because type II inhibitors have greater selectivity than type I TKIs.
Vorolanib, sunitinib, and axitinib exhibited pan-VEGFR inhibition and inhibited RTKs associated with pathological angiogenesis. Of the three TKIs, only axitinib potently inhibited TIE2 which is an undesired trait as TIE2 is essential for vascular stability. The findings support the use of vorolanib for therapeutic inhibition of angiogenesis observed in DR, DME, and wAMD.
病理性血管生成和血管不稳定可见于糖尿病性视网膜病变（DR）、糖尿病性黄斑水肿（DME）和湿性年龄相关性黄斑变性（wAMD）。许多受体酪氨酸激酶（RTKs），包括血管内皮生长因子受体（VEGFRs），有助于血管生成，而 RTK TIE2 对血管稳定性很重要。泛血管内皮生长因子受体酪氨酸激酶抑制剂（TKIs），如凡德他尼、舒尼替尼和阿昔替尼，在治疗上比目前仅针对一种或两种配体的抗体治疗更有意义。本研究比较了这些 TKI 的抗血管生成潜力。
激酶热点测定法用于鉴定与血管生成和血管稳定性相关的 RTK 的 TKI。每种 TKI 的 VEGFR 和 TIE2 的半最大抑制浓度（IC50）均进行了测定。采用人脐静脉内皮细胞出芽试验研究体外血管生成抑制，采用鸡胚尿囊膜试验研究体内血管生成。采用黑色素结合试验评估黑色素结合。通过计算机建模了解 TIE2-阿昔替尼复合物以及凡德他尼与 VEGFRs 之间的相互作用。
凡德他尼、舒尼替尼和阿昔替尼抑制了血管生成中感兴趣的 RTKs，并表现出泛 VEGFR 抑制作用。热点测定法和 TIE2 IC50 值表明，只有阿昔替尼能强有力地抑制 TIE2（高达 89%）。三种 TKI 均能有效抑制体外血管生成。在体内，TKI 比抗 VEGF 抗体贝伐单抗更能抑制 VEGF 诱导的血管生成。在这三种 TKI 中，只有舒尼替尼结合黑色素。TKI 在分类和与 VEGFRs 的结合上存在差异，这很重要，因为 II 型抑制剂比 I 型 TKI 具有更高的选择性。
凡德他尼、舒尼替尼和阿昔替尼均表现出泛 VEGFR 抑制作用，并抑制了与病理性血管生成相关的 RTKs。在这三种 TKI 中，只有阿昔替尼能强有力地抑制 TIE2，这是一种不理想的特征，因为 TIE2 对血管稳定性至关重要。这些发现支持将凡德他尼用于治疗 DR、DME 和 wAMD 中观察到的血管生成抑制。
