其他名称：Bexxar。
作用机制：131I-Tositumomab是一种鼠抗CD20抗体IgG2a,用131I标记．131I能释放B和Y射线．作用机制包括抗体介导的细胞毒作用和细胞靶向放射免疫治疗。
主要适应症：化疗无效，CD20阳性，分化低的非霍奇金淋巴瘤。
常用剂量及方案：在放射和治疗剂量前，先给予醋酸酚650mg和苯海拉明50mg．碘化钾饱和液２~３滴，口服每日３次，放射剂量前２４小时开始服用，治疗剂量结束后再服用１４天．以防止甲状腺摄取131I。
１　放射测定剂量：先给予未标记的Tositumomab,450mg静滴１小时，继以131I-Tositumomab
5mCi(35mg)静滴２０分钟。以监测病人对131I-Tositumomab的最适剂量，然后给予治疗剂量65-75cGy，７－１５天。
２　治疗剂量：先给予未标记的Tositumomab450mg,静滴１小时，然后给予病人最适剂量的131I-Tositumomab35mg(平均90 mCi,范围为50-200 mCi)。

注意事项：
1）淋巴瘤骨髓侵犯超过２５％，骨髓外照射超过２５％或有HAMAS(HACAS)病者慎用。

2）放疗前24小时口服碘化钾饱和液，每天3次，每次2~3滴，连用14天。
毒性反应：

1、骨髓抑制和其他血液学毒性：髓系抑制十分常见。２０％病人出现IV级血小板减少或中性粒细胞减少。

2、恶心，呕吐和其他胃肠道反应：恶心常见，呕吐，腹痛和厌食偶见。

3、皮肤粘膜反应：瘙痒，皮疹偶见。

4、其他：

１）可能发生HAMAS或HACAS。
２）注射反应偶见至常见，大部分为自限性。
３）乏力或衰弱常见。
４）咳嗽水肿偶见，呼吸困难少见。
５）预防应用碘化钾时，甲状腺功能抑制少见。
６）治疗后２０~４０个月，偶见骨髓发育不良

FDA扩大托西莫单抗疗法(Bexxar)治疗非霍奇金淋巴瘤的适应证

美国FDA批准扩大托西莫单抗加I131疗法(Bexxar，葛兰素史克生产)的适应证，删去其只能针对美罗华抵抗而且化疗后复发的非霍奇金淋巴瘤(NHL)的限制。

这一新适应证批准的依据是一项多中心、单组、开放式研究的结果，该研究有60例化疗抵抗患者参加，他们的中位年龄是60岁，中位诊断时间53个月，中位先前化疗次数是4次。大多数患者(88%)对先前的治疗无应答，12%患者的缓解时间在6个月以内。托西莫疗法显示其总缓解率为47%(95%CI，34%-60%)，中位缓解时间为12个月(2-47个月；95%CI，7-47个月)。中位随诊30个月时，达到完全缓解的患者占20%(95%CI，11%-32%)，中位缓解时间为47个月(9-47个月；95%CI，47个月-未达到)。

该疗法目前的适应证为，有CD20抗原表达的复发性或抵抗性、低度、恶性、滤泡性或转换性NHL，包括对美罗华抵抗的NHL患者。

注：以下产品不同规格和不同价格，购买时请以电话咨询为准！
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原产地英文商品名:
BEXXAR 131 Iodine Dosimetric 20mL/Vial
原产地英文药品名:
Tositumomab Iodine-131
中文参考商品译名:
百克沙131I/剂量测定-20毫升/瓶
中文参考药品译名:
托西莫单抗 I-131
生产厂家中文参考译名:
葛兰素史克公司
生产厂家英文名:
GlaxoSmithKline
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原产地英文商品名:
BEXXAR Dosimetric-14mg/mLx34.7mL/Vial
原产地英文药品名:
Tositumomab
中文参考商品译名:
百克沙/剂量测定-14毫克/毫升,34.7毫升/瓶
中文参考药品译名:
托西莫单抗
生产厂家中文参考译名:
葛兰素史克公司
生产厂家英文名:
GlaxoSmithKline
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The BEXXAR Therapeutic Regimen,a Radioimmunotherapy for non-Hodgkin's lymphoma

The BEXXAR therapeutic regimen (Tositumomab and Iodine I 131 Tositumomab) is indicated for the treatment of patients with CD20 antigen-expressing relapsed or refractory, low-grade, follicular, or transformed non-Hodgkin’s lymphoma, including patients with Rituximab-refractory non-Hodgkin’s lymphoma.

Determination of the effectiveness of the BEXXAR therapeutic regimen is based on overall response rates in patients whose disease is refractory to chemotherapy alone or to chemotherapy and Rituximab. The effects of the BEXXAR therapeutic regimen on survival are not known.

The BEXXAR therapeutic regimen is not indicated for the initial treatment of patients with CD20-positive non-Hodgkin’s lymphoma. The BEXXAR therapeutic regimen is intended as a single course of treatment. The safety of multiple courses of the BEXXAR therapeutic regimen, or combination of this regimen with other forms of irradiation or chemotherapy, has not been evaluated.

Hypersensitivity Reactions, Including Anaphylaxis: Serious hypersensitivity reactions, including some with fatal outcome, have been reported with the BEXXAR therapeutic regimen. Medications for the treatment of severe hypersensitivity reactions should be available for immediate use. Patients who develop severe hypersensitivity reactions should have infusions of the BEXXAR therapeutic regimen discontinued and receive medical attention (see WARNINGS in Prescribing Information).

Prolonged and Severe Cytopenias: The majority of patients who received the BEXXAR therapeutic regimen experienced severe thrombocytopenia and neutropenia. The BEXXAR therapeutic regimen should not be administered to patients with >25% lymphoma marrow involvement and/or impaired bone marrow reserve (see WARNINGS and ADVERSE REACTIONS in Prescribing Information).

Pregnancy Category X: The BEXXAR therapeutic regimen can cause fetal harm when administered to a pregnant woman.

Special Requirements: The BEXXAR therapeutic regimen (Tositumomab and Iodine I 131 Tositumomab) contains a radioactive component and should be administered only by physicians and other healthcare professionals qualified by training in the safe use and handling of therapeutic radionuclides. The BEXXAR therapeutic regimen should be administered only by physicians who are in the process of being or have been certified by GlaxoSmithKline in dose calculation and administration of the BEXXAR therapeutic regimen.

IMPORTANT SAFETY INFORMATION¹

Contraindications: The BEXXAR therapeutic regimen (Tositumomab and Iodine I 131 Tositumomab) is contraindicated in patients with known hypersensitivity to murine proteins or any other component of BEXXAR.

BEXXAR is contraindicated for use in women who are pregnant.

Data regarding adverse events were primarily obtained in 230 patients with non-Hodgkin’s lymphoma enrolled in 5 clinical trials. Data from 765 patients enrolled in an expanded access program were used to supplement the characterization of delayed adverse events.

Prolonged and Severe Cytopenias: The majority of patients, 71% of 230, who received the BEXXAR therapeutic regimen, experienced severe or life-threatening (Grade 3/4) cytopenias. The most common were thrombocytopenia (53%) and neutropenia (63%). Time to nadir was 4-7 weeks, lasting approximately 30 days. Due to the variable nature of the onset of the cytopenias, complete blood counts should be obtained weekly for 10-12 weeks. More frequent monitoring is indicated in patients with evidence of moderate or more severe cytopenias. Blood counts should be monitored weekly until severe cytopenias have resolved. Sequelae included infections (45%), hemorrhage (12%), and requirement for hematological supportive care (27%).

Hypersensitivity Reactions Including Anaphylaxis: Hypersensitivity reactions, including some with fatal outcome, were reported during and following administration of the BEXXAR therapeutic regimen in 6% (14) of 230 patients. In the postmarketing setting, severe hypersensitivity reactions, including fatal anaphylaxis, have been reported. Patients who have received murine proteins should be screened for human anti-mouse antibodies (HAMA) as they may be at increased risk for serious allergic reactions.

Immunogenicity: Administration of BEXXAR may result in the development of HAMA. Of the 230 patients in the clinical studies, 220 patients were seronegative for HAMA prior to treatment, and 219 had at least 1 posttreatment HAMA value obtained. With a median observation period of 6 months, a total of 23 patients (11%) became seropositive for HAMA posttreatment. The median time of HAMA development was 6 months. The cumulative incidences of HAMA seropositivity at 6 months, 12 months, and 18 months were 6%, 17%, and 21%, respectively. The presence of HAMA may affect the toxicity and/or efficacy of in vivo diagnostic or therapeutic agents that rely on murine antibodies and may affect the accuracy of in vitro and in vivo diagnostic tests.

Secondary Leukemia, Myelodysplastic Syndrome (MDS), and Secondary Malignancies: At a median follow-up of 29 months, 44 cases of myelodysplastic syndrome and/or secondary leukemia were reported in 995 patients enrolled in clinical studies and an expanded access program. Additional malignancies (65 cases) were also reported in 54 of the patients. Approximately half of these were nonmelanomatous skin cancers (26). The remainder, which occurred in 2 or more patients, included colorectal cancer, head and neck cancer, breast cancer, lung cancer, bladder cancer, melanoma, and gastric cancer, in order of decreasing incidence. The relative risk of developing secondary malignancies in patients receiving BEXXAR over the background rate in this population cannot be determined due to the absence of controlled studies.

Hypothyroidism: Administration of BEXXAR may result in hypothyroidism. Of the 230 patients in the clinical studies, 203 patients did not have elevated thyroid-stimulating hormones (TSH) upon study entry. Of these, 137 patients had at least 1 posttreatment TSH value available and were not taking thyroid hormonal treatment upon study entry. With a median follow-up period of 46 months, the incidence of hypothyroidism based on elevated TSH or initiation of thyroid replacement therapy in these patients was 18%, with a median time to development of hypothyroidism of 16 months. The cumulative incidences of hypothyroidism at 2 and 5 years in these 137 patients were 11% and 19%, respectively. New events have been observed up to 90 months posttreatment. Of the 765 patients in the expanded access programs, 670 patients did not have elevated TSH upon study entry. Of these, 455 patients had at least 1 posttreatment TSH value available and were not taking thyroid hormonal treatment upon study entry. With a median follow-up period of 33 months, the incidence of hypothyroidism based on elevated TSH or initiation of thyroid replacement therapy in these 455 patients was 13%, with a median time to development of hypothyroidism of 15 months. The cumulative incidences of hypothyroidism at 2 and 5 years in these patients were 9% and 17%, respectively. Thyroid-blocking medication should be prescribed as described in the prescribing information; if patients do not tolerate the medication they should not be given BEXXAR. Patients should be evaluated for signs and symptoms of hypothyroidism and screened for biochemical evidence of hypothyroidism annually.

Infusional Toxicities: Infusional toxicities including fever, rigors, chills, sweating, nausea, hypotension, dyspnea, and bronchospasm have been reported during and/or following the infusion of BEXXAR. Fever, rigors, chills, or sweating were reported in 67 patients (29%) within 14 days following the dosimetric dose. Infusional toxicities were managed by slowing and/or temporarily interrupting the infusion. Adjustments occurred in 7% of the patients and included reduction in the rate of infusion by 50%, temporary interruption of the infusion, and in 2 patients, infusion was permanently discontinued.

Assessment of Biodistribution: The biodistribution of Iodine I 131 Tositumomab should be assessed. If biodistribution is altered, the therapeutic dose should not be administered.