Scientists at McMaster University in Ontario and colleagues in California, Sweden, and other provinces of Canada are formulating a therapy with a different perspective on treating asthma. If the new agent, produced by Genetech under the name Xolair (quilizumab), reduces symptoms superior to other asthma medications, one more medication for patients with severe asthma may eventually become available.
The primary goal of treating asthma is reducing symptoms by opening the airways or reducing inflammation. For some patients, these treatments are not enough for their severe asthma, and they continue to suffer from wheezing, coughing, and shortness of breath.
A main cause of inflammation in the airways is immunoglobulin E (IgE), a protein in the blood produced by plasma cells. IgE activates mast cells to produce histamine in response to allergens such as pollen and dust mites.
In the new study, published in Science Translational Medicine and sponsored by Genetech, the research team was interested in whether Xolair could block IgE production. It was shown previously Xolair neutralizes IgE circulating in the blood, but Xolair would be more effective if it could prevent IgE production altogether.
The research team administered one to three doses of Xolair for two months, spaced four weeks apart, to 65 individuals with either hay fever or mild asthma. At the end of the study period, individuals had lower amounts of IgE in their blood, and these effects lasted for at least six months past the last dose. Xolair was effective in inhibiting IgE production in response to specific allergens.
Results have created a stir among the clinical community. “It’s always exciting when it’s a new target that we haven’t had,” said Dr. Rohit Katial, from the National Jewish Medical & Research Center in Colorado, in a news report. Yet more clinical studies are necessary before Xolair can be marketed to asthma sufferers. “[T]here’s no way to know how it’s going to behave clinically,” said Dr. Katial, who is unrelated to the research.