Bexxar(百克沙)——治疗CD20阳性非Hodgkin淋巴瘤
原产地英文药品名:Tositumomab Bexxar; 治疗CD20阳性的小囊性非霍杰金氏淋巴瘤化疗复发的病人; Corixa生产; 2003年6月批准上市Bexxar治疗非Hodgkin淋巴瘤。

有关专家最近呈交于美国血液病学会(ASH)年会的研究报告表明，单克隆抗体药物Bexxar具有缓解非Hodgkin淋巴瘤(NHL)的长期效应。

NHL是一种起始于淋巴细胞的癌症，主要表现为非典型或癌变淋巴细胞的过量积聚，进而充塞于整个淋巴系统而抑制其它免疫细胞和血细胞的生成以及行使其正常功能。由于常规化疗和放疗往往会导致某些严重的副作用，研究人员多年来一直在探讨新型疗法，其中之一就是放射免疫治疗，即将某种放射剂与特定的抗体连接起来，后者能够和癌细胞专一性结合，因而使辐射直接作用在癌细胞上而不影响其周边的正常组织。

Bexxar正是这类新型放射免疫制剂，结合有放射性碘131，其抗体部分能够专一性与癌变了的B-淋巴细胞表面特有的蛋白CD20相结合。近期完成的5项临床研究结果证实，Bexxar的抗NHL反应平均可持续14个月，30%的患者体内完全检测不到癌细胞，而在大约8年的随访期间这些患者中有70%以上没有复发。
 
【商 品 名】Bexxar
【通 用 名】Tositumaomab
【中 文 名】
【开发公司】葛兰素史克（Glaxo Smithk line）
【销售公司】葛兰素史克（Glaxo Smithk line）
【药物种类】omab：鼠源单抗，放射性碘131以Tositumaomab抗体为载体。
【靶    点】CD—20抗原。
【适 应 症】Hodgkin 淋巴瘤（NHL）
【临床阶段】美国FDA：2003年6月批准上市。
【作用机制】通过放射性碘131以Tositumaomab抗体为载体，与NHL癌变的B-淋巴细胞表面特有白蛋白CD-20结合。放射性碘131杀死癌细胞。
【用法用量】
【贮藏条件】避光2℃-8℃，避免剧烈摇晃。
【规    格】14mg×34.7ml   0.61MC×34.7ml
【剂    型】百克沙 14毫克/毫升；34.7毫升/瓶
【药价与规格】
Bexxar 14mg/ml Tositumomab 34.7ml $2992.89美圆
Bexxar 0.61 MC Tositumomab 34.7ml $3545.89美圆

U-M study finds lymphoma drug effective over long term
86% of patients treated with Bexxar survived after 8 years of follow up
--added 6/4/07
Ann Arbor, MI. -- Eight years after being treated with a new drug for non-Hodgkin's lymphoma, 86 percent of patients were still alive and half had not had a relapse of their disease, according to researchers from the University of Michigan Comprehensive Cancer Center

The patients had follicular lymphoma, a type of cancer that is not considered to be curable using traditional treatments. Even if patients initially respond to treatment, the disease almost always comes back and becomes more difficult to treat.

The study followed 76 patients with follicular non-Hodgkin's lymphoma, a cancer of the lymph system, who received the radioimmunotherapy drug Bexxar as their first treatment for the disease. Ninety-five percent of the patients saw their tumors shrink from the treatment and three-quarters of patients went into complete remission. Patients were followed for a median of eight years, and nearly two-thirds have remained in complete remission eight years after treatment.

 "For years we have known radioimmunotherapy such as Bexxar is one of the most effective treatments for patients with relapsed follicular lymphoma. These data show Bexxar is particularly effective when used as a front-line treatment," says Mark Kaminski, M.D., professor of internal medicine at the U-M Medical School. Kaminski will present these results June 4 at the American Society of Clinical Oncology annual meeting in Chicago.

"These results compare quite favorably with those achieved with state-of-the-art chemotherapy regimens that take months to deliver. But Bexxar is given as a single treatment, completed within one week, which makes it an extremely convenient regimen for patients," Kaminski says.

Non-Hodgkin's lymphoma, the nation's sixth leading cause of cancer death, is a cancer of the lymph system, which is part of the immune system. Follicular lymphoma is the second most common type of non-Hodgkin's lymphoma. Lymphoma spreads easily through the lymph system and the bloodstream and consequently tends to be widespread when it is diagnosed. Traditional treatment often involves intensive chemotherapy, or a combination of chemotherapy and the monoclonal antibody rituximab. These treatments are usually given every three weeks over a span of up to six months and can cause many unpleasant side effects, including nausea, hair loss and infections.

Bexxar, whose chemical name is tositumomab and iodine I 131 tositumomab, combines an antibody that seeks out cancer cells, and a radioactive form of the element iodine. When injected, it travels like a guided missile through the bloodstream to bind to a protein found on the surface of the cancerous cells. The radiation zaps these malignant cells with minimal exposure to normal tissues.

With the Bexxar therapeutic regimen, a patient receives an injected test dose of radioactive Bexxar, followed one to two weeks later with a custom-tailored therapeutic dose. After that, the therapy is considered complete. The most common side effect is a temporary lowering of blood counts several weeks after the treatment. There is no hair loss and nausea is rare.

Kaminski and his colleague Richard Wahl (formerly at U-M and now at Johns Hopkins University) developed the Bexxar regimen, which received approval from the U.S. Food and Drug Administration in June 2003 to treat follicular non-Hodgkin's lymphoma after other treatments have failed. The current results involve Bexxar as a first-line treatment for this disease.

In addition to Kaminski and Wahl, U-M study authors were Judith Estes, R.N., a nurse practitioner; Missy Tuck, clinical research coordinator; and Charles Ross, M.D., associate professor of pathology.

Funding for the study was from the National Institutes of Health and GlaxoSmithKline. The University of Michigan holds patents for the Bexxar therapeutic regimen, which is marketed by GlaxoSmithKline under a licensing agreement. U-M receives royalties on sales of Bexxar, a portion of which goes to Kaminski and his co-inventors.

For information about non-Hodgkin's lymphoma, visit our Non-hodgkins lymphoma web page or call the Cancer AnswerLine at 800-865-1125. For information about Bexxar from its manufacturer, call 877-4-BEXXAR or visit www.bexxar.com.

Reference: American Society of Clinical Oncology 43rd annual meeting, June 1-5, 2007, Chicago, Ill. Abstract No. 8033.

Written by Nicole Fawcett

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