By now, the adverse effects of the asthma medication Xolair® have been well-reported by sources including WebMD, Lung Disease News and the Food and Drug Administration. Most serious among these complications are chest pain, heart attacks, “mini-strokes,” blood clots, brain issues and a severe, life-threatening allergic reaction known as anaphylaxis. There is even some evidence that it may increase the risk of cancer - which may have to do with its mechanism of action, or how the medication works in the body.
Xolair's pharmacological name sounds like a creature out of H.P. Lovecraft. Omalizumab is synthesized from antibodies obtained from ovarian DNA of the Chinese hamster, a rodent, which have been genetically engineered to work in the human body. The medication is intended to treat asthma, a chronic inflammatory condition of the respiratory system. While medical science believes there to be a genetic basis for the disease, attacks are usually triggered by environmental factors, such as dust, pollen, soot, smoke or other allergens.
Recently, Xolair has been approved in the U.S. and Canada for the treatment of chronic hives, an auto-immune condition.
This is what asthma and hives have in common: the body's own immune system goes into overdrive, or overreacts to a perceived threat (the medical description is “hypersensitivity”). Think of white blood cells as gatekeepers. If they encounter a cell that is a possible invader, they produce antibodies. The antibody involved in allergic reactions is known as “immunoglobulin E,” or IgE for short. When allergenic proteins bind to receptor cells of IgE antibodies, the result is inflammation or an allergic reaction. Xolair is designed to inhibit this binding process.
This is where some medical researchers believe the connection to a greater cancer risk occurs. In 2003, a group of researchers from the U.K. and the U.S. published the results of a study in the European Journal of Immunology, in which they found strong evidence that the IgE antibody plays a significant role in the recognition and inhibition of malignant tumors. Xolair is not selective in the way it blocks IgE receptors from binding to allergens – and this may interfere with the way these antibodies detect pre-cancerous cells.
Although a review of a five-year safety study by the FDA “found no difference in the rates of cancer between those patients being treated with Xolair and those who were not,” the regulatory body acknowledges that “due to limitations in the study, we cannot rule out a potential cancer risk.”