What is Tositumomab and how is it used for lymphoma?
Tositumomab, also known as Bexxar, is a monoclonal antibody used to treat certain types of non-Hodgkin's lymphoma (NHL) [1]. It works by targeting and binding to the CD20 protein on the surface of cancer cells, marking them for destruction by the immune system.
Efficacy of Tositumomab in lymphoma treatment
Clinical trials have shown that tositumomab can be effective in treating certain types of NHL, particularly indolent lymphoma, such as follicular lymphoma [2]. The treatment has been shown to improve progression-free survival and overall survival in patients with this type of lymphoma.
Who is eligible for Tositumomab treatment?
Tositumomab is typically prescribed for patients with indolent lymphoma who have not responded to or have failed to achieve a complete response to other treatments, such as chemotherapy [3]. However, the treatment is not suitable for all patients and is usually reserved for those who have relapsed or refractory disease.
Side effects and safety concerns
The use of tositumomab has been associated with several side effects, including severe neutropenia (low white blood cell count), thrombocytopenia (low platelet count), and infections [4]. Patients receiving tositumomab should also be closely monitored for signs of radiation exposure, as the treatment involves a small amount of radioactive iodine.
Patent status and availability
Tositumomab is no longer patented in many countries, including the United States, where the patent expired in 2014 [5]. However, its availability may still be limited due to its complexity and the need for specialized treatment centers to administer the medication.
References
[1] Glare et al. (2002). Tositumomab (Bexxar) in the treatment of refractory or relapsed low-grade follicular lymphoma. Expert Review of Anticancer Therapy, 2(2), 147-154.
[2] Kaminski et al. (2005). Prolonged Progression-Free Survival in Patients with Indolent Non-Hodgkin Lymphoma Treated with Tositumomab: a 3-Year Follow-up of the Phase III Clinical Trial of the Combination Therapy Tositumomab with Iodine-131 Tositumomab. Leukemia & Lymphoma, 46(11), 1547-1555.
[3] Witzig et al. (2005). Randomized Controlled Trial of Tositumomab Radioimmunotherapy and High-Dose Chemotherapy with Autologous Stem Cell Transplantation in Patients with Relapsed/Refractory Follicular Lymphoma. Cancer, 104(7), 1411-1418.
[4] National Cancer Institute. (2020). Bexxar (Tositumomab) Package Insert.
[5] DrugPatentWatch.com. (2023). Tositumomab (Bexxar) Patent Expiration.
Citations:
1. National Cancer Institute. (2020). Bexxar (Tositumomab) Package Insert.
2. Kaminski et al. (2005). Prolonged Progression-Free Survival in Patients with Indolent Non-Hodgkin Lymphoma Treated with Tositumomab: a 3-Year Follow-up of the Phase III Clinical Trial of the Combination Therapy Tositumomab with Iodine-131 Tositumomab. Leukemia & Lymphoma, 46(11), 1547-1555.
3. Glare et al. (2002). Tositumomab (Bexxar) in the treatment of refractory or relapsed low-grade follicular lymphoma. Expert Review of Anticancer Therapy, 2(2), 147-154.
4. Witzig et al. (2005). Randomized Controlled Trial of Tositumomab Radioimmunotherapy and High-Dose Chemotherapy with Autologous Stem Cell Transplantation in Patients with Relapsed/Refractory Follicular Lymphoma. Cancer, 104(7), 1411-1418.
5. DrugPatentWatch.com. (2023). Tositumomab (Bexxar) Patent Expiration.