Tositumomab Overview

Introduction of Tositumomab

Tositumomab is a murine IgG2a lambda monoclonal antibody directed against CD20 molecular, which is a transmembrane phosphoprotein expressed on pre-B-lymphocytes and mature B-lymphocytes. This drug combination was developed by Corixa which was purchased by GlaxoSmithKline in 2005 and has been investigated in a trial of the treatment of non-Hodgkin's lymphomas. In combination with a radioactive atom Iodine - 131, tositumomab has been used for the treatment of patients with CD20 positive, relapsed or refractory, low-grade, follicular, or transformed non-Hodgkin's lymphoma who have progressed during or after rituximab therapy, including patients with rituximab-refractory non-Hodgkin's lymphoma. This drug was approved by the U.S. Food and Drug Administration (FDA) in 2003 under the trade name Bexxar. Unfortunately, Bexxar ceased sales in February 2014 and market approvals were withdrawn because of the decline in Bexxar's usage. In addition, the orphan designation was granted by the European Commission to Amersham plc, U.K., for tositumomab for the treatment of follicular lymphoma on 14 February 2003.

Mechanism of Action of Tositumomab

Tositumomab is a protein drug that usually radiolabeled with iodine I 131, which has potential antineoplastic activity. Tositumomab is a monoclonal antibody that could bind to the CD20 surface membrane antigen expressed on the B-lymphocytes. Binding of tositumomab to CD20 appears to induce apoptosis and may stimulate antitumoral cell-mediated and/or antibody-dependent cytotoxicity. In addition, when the antibody attaches to the CD20 antigens, the radiation from radioactive elements iodine I 131 is delivered directly to the targeted cells killing the targeted cells as well as cancer cells in the immediate area by ionizing radiation. Besides, a mechanism of potential vaccine-like effect leading to adaptive immunity against cells that survive initial treatment is also suggested.

Fig.1 Mechanism of action of Tositumomab

Table 1. Clinical Projects of Tositumomab*

What We Provide

Therapeutic Antibody

Tositumomab

We provide high-quality Tositumomab for use in WB, FC, IP, ELISA, Neut, FuncS, IF and most other immunological methods. For lab research use only, not for diagnostic, therapeutic or any in vivo human use.

Reference
* The table was excerpted from the following website
https://clinicaltrials.gov/ct2/results?cond=&term=Tositumomab

For research use only. Not intended for any clinical use.