Witzig T E
Division of Internal Medicine and Hematology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
Semin Oncol. 2000 Dec;27(6 Suppl 12):74-8.
Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA and IDEC Pharmaceutical Corporation, San Diego, CA) is a monoclonal antibody that targets the CD20 antigen present in most B-cell non-Hodgkin's lymphomas. Previous studies have shown overall response rates (ORR) of approximately 50% in relapsed patients. Ibritumomab is the murine parent anti-CD20 antibody that is linked through a MX-DTPA chelator to yttrium 90 (90Y) to form the radioimmunoconjugate 90Y-ibritumomab tiuxetan (Zevalin; IDEC Pharmaceuticals, San Diego, CA). A phase I study of 90Y-ibritumomab tiuxetan determined that 0.4 mCi/kg was the maximum tolerated dose, and responses were reported in 67% of all patients and in 82% of patients with low-grade non-Hodgkin's lymphoma. A separate trial randomized eligible patients to either rituximab or 90Y-ibritumomab tiuxetan. An interim analysis of the first 90 patients showed an ORR of 80% with 90Y-ibritumomab tiuxetan versus 44% with rituximab (P < .05). A subsequent trial for patients with rituximab-refractory disease showed a 46% ORR. These studies show that 90Y-ibritumomab tiuxetan is an active agent in relapsed non-Hodgkin's lymphoma and appears to have a higher ORR compared with unconjugated rituximab.
利妥昔单抗（美罗华；基因泰克公司，加利福尼亚州南旧金山，以及IDEC制药公司，加利福尼亚州圣地亚哥）是一种单克隆抗体，可靶向大多数B细胞非霍奇金淋巴瘤中存在的CD20抗原。先前的研究表明，复发患者的总体缓解率（ORR）约为50%。伊布替尼单抗是鼠源抗CD20抗体，它通过MX-DTPA螯合剂与钇90（90Y）连接，形成放射免疫缀合物钇90-伊布替尼单抗（泽瓦林；IDEC制药公司，加利福尼亚州圣地亚哥）。一项关于钇90-伊布替尼单抗的I期研究确定，0.4mCi/kg是最大耐受剂量，所有患者中有67%以及低度非霍奇金淋巴瘤患者中有82%报告有反应。另一项试验将符合条件的患者随机分为接受利妥昔单抗或钇90-伊布替尼单抗治疗。对前90例患者的中期分析显示，钇90-伊布替尼单抗的ORR为80%，而利妥昔单抗为44%（P<0.05）。随后一项针对利妥昔单抗难治性疾病患者的试验显示ORR为46%。这些研究表明，钇90-伊布替尼单抗是复发非霍奇金淋巴瘤的一种有效药物，与未缀合的利妥昔单抗相比，其ORR似乎更高。
