Rituximab
In 1997, rituximab became the first antibodyAntibody molecules tightly bind to their targets (usually proteins) with great specificity. Antibody binding alerts the immune system to target the bound molecule for destruction. Specific antibodies can be made in the laboratory. approved for the treatment of cancer in the United States. Rituximab is used in the treatment of low-grade relapsed or refractory (treatment resistant) Non-Hodgkin's LymphomaA cancer arising in the lymphatic system. The white blood cells affected are part of the body's immune system. The lymphatic system is a large network of vessels that carry fluid and cells of the immune system around the body. Lymph nodes are regional collection centers in the lymphatic system. See also, 'lymphatic system'., as well as CLL. Rituximab is administered as an IV infusion once a week usually for 4 to 8 doses.1
Rituximab is a genetically engineered monoclonalDerived from a single source. In the context of cancer, the term is used in two ways: 1) to refer to the fact that tumors arise from a single damaged cell and 2) to describe the antibodies used in the treatment of cancer. antibodyAntibody molecules tightly bind to their targets (usually proteins) with great specificity. Antibody binding alerts the immune system to target the bound molecule for destruction. Specific antibodies can be made in the laboratory. containing both human and mouse components. It is directed against the CD20 antigenAny substance capable of being recognized by the immune system. Recognition of such a substance leads to the generation of an immune response.. The CD20 proteinOne of the four basic types of biomolecule. Proteins are polymers made up of strings of amino acids. Proteins serve many functions in organisms including transport of molecules, structure, cell adhesion and as signaling molecules such as hormones. Many transcription factors, including p53 and Rb are proteins. is present on the majority of mature B-cells but not on B-cells in the bone marrow. The drug allows the repopulation of the blood with B-cells after treatment ends. Binding of the antibody stimulates the destruction of the tagged cells. Evidence also suggests that rituximab may induce apoptosisAlso called programmed cell death. Apoptosis is a natural process that occurs throughout the lives of almost all animals and plants. The death of the cells is a carefully controlled process that does not generate any inflammation. in cells. Note that the image shown is a general structure of an antibody. There are four proteins bound together in a 'Y' shape. The two top tips of the Y are where the antibody binds with its target. This means that each antibody molecule can bind to two identical target regions.1
The diagram above shows the 3D molecular structure of Rituximab.
The most common side effects include fever, chills, infection, lowered lymphocyteA immune cell that resides primarily in the lymphatic system. The lymphocytes include T-cells (cells involved in the control of immune responses and cellular cytotoxicity) and B-cells (cells that produce antibodies or immunoglobulins). count. Infusion reactions may also occur. During the first infusion many patients experience such a reaction with fever and chills. These symptoms can be treated with other medications or by slowing or stopping the infusion. Other, more severe reactions may also occur. Some patients may also experience pulmonary side effects that include cough and rhinitis. Other patients may experience more severe side effects. 1
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