How does hOKT3γ1(Ala-Ala) work? Type 1 diabetes mellitus (or T1DM), like other autoimmune diseases, occurs due to a malfunction in the immune system that causes it to attack cells and tissues of the host's (patient's) own body. In T1DM, the targets for this mistaken identity are the insulin-producing beta cells located in the pancreas. When the immune cells attack they destroy the beta cells, eventually leading to the inability to produce insulin in response to elevated levels of glucose in the blood, a condition known as hyperglycemia.
When the immune system attacks, it sends a type of white blood cell known as "T cells" to do the job. The surface of each T cell is coated with thousands of specialized receptors - T cell receptors. All the receptors on a specific T cell are the same; and all these receptors are designed to bind only very specific proteins located on the surface of other cells, known as antigens. When the T cell receptor binds to the antigen that it was designed for, the T cell is effectively "turned on" and is primed to go on the attack. The exact antigen of the beta cells that the T cell receptor binds to in type 1 diabetes is not yet known. hOKT3γ1(Ala-Ala) [teplizumab] is a monoclonal antibody designed to interfere with T cell activation by their corresponding antigen. Antibodies are specialized proteins that can very precisely "recognize" and bind to certain shapes of other molecules - teplizumab is a "monoclonal" antibody because it binds only one very specific shape. It has been designed to bind to a molecule closely associated with the T cell receptor, known as "CD3". Although the precise mechanisms is not yet clear, in binding the CD3 molecule, teplizumab essentially interferes with the interaction between the T cell and its antigen, preventing the T cells from doing their damage. Often, at the time of diagnosis of T1DM the immune system has not yet destroyed all of the beta cells in the pancreas. In general, between 15-40% remain functional in the newly diagnosed individual. It is believed that teplizumab can help prevent the autoimmune attack on the beta cells, sparing those remaining cells so that they may continue to produce much needed insulin. Teplizumab is manufactured by Macrogenics, Inc. |
More Info on Patient Information Drug slows diabetes in young patients Drug shows great promise against juvenile diabetes The little antibody that could Physician Information Pilot phase I/II trial results in new onset diabetes at 1 year - NEJM 2002 (pdf) Pilot phase I/II trial results in new onset diabetes at 2 years
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