Irinotecan and Cetuximab With or Without Bevacizumab in Treating Patients With Metastatic Colorectal Cancer That Progressed During First-Line Therapy

This randomized phase III trial is studying giving irinotecan and cetuximab together with bevacizumab to see how well it works compared with giving irinotecan and cetuximab alone in treating patients with metastatic colorectal cancer that progressed during first-line therapy. Drugs used in chemotherapy, such as irinotecan, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as cetuximab and bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Bevacizumab may also stop the growth of tumor cells by blocking blood flow to the tumor. It is not yet known whether irinotecan and cetuximab are more effective with or without bevacizumab in treating metastatic colorectal cancer.

本项随机对照III期临床试验（randomized phase III trial）旨在评估伊立替康（irinotecan）联合西妥昔单抗（cetuximab）与贝伐珠单抗（bevacizumab）的联合用药方案，对比伊立替康联合西妥昔单抗单用方案，针对一线治疗（first-line therapy）期间出现进展的转移性结直肠癌（metastatic colorectal cancer）患者的临床疗效。伊立替康等化疗药物可通过多种机制抑制肿瘤细胞增殖，包括直接杀伤肿瘤细胞或阻断其分裂过程。西妥昔单抗、贝伐珠单抗等单克隆抗体（monoclonal antibodies）则通过不同途径阻断肿瘤生长：部分可抑制肿瘤细胞的增殖与扩散能力；部分可靶向识别肿瘤细胞，协助杀伤肿瘤细胞或向其递送抗肿瘤物质。贝伐珠单抗还可通过阻断肿瘤血供，抑制肿瘤细胞增殖。目前尚不明确，在伊立替康联合西妥昔单抗的基础上加用贝伐珠单抗，是否可提升转移性结直肠癌的治疗效果。