At McMaster University in Ontario, Canada, researchers claim to have successfully tested an antibody that relieves inflammation in the lungs of asthma patients.
The standard treatments for people with asthma are inhaled corticosteroids or bronchodilators, taken regularly to control asthma symptoms. Currently, only people with severe asthma receive antibody treatments.
However, the researchers behind the new study believe their research could lead to antibody treatments appropriate for people with mild allergic asthma. As some patients have problems with steroid-based treatments, an antibody treatment could improve quality of life for many asthma patients.
One of the leaders of the new study, Dr. Paul O'Byrne, executive director of the Firestone Institute of Respiratory Health at St. Joseph's Healthcare Hamilton and chair of the Department of Medicine at McMaster University, says:
"It was known that the epithelial cells which line the airways in the lungs produce a protein called thymic stromal lymphopoietin (TSLP) that causes inflammation. This study, for the first time, proved that these cells continually produce this protein in humans with asthma."
Blocking the TSLP protein in the lungs with an antibody reduces inflammation and provides resistance to allergens for people with mild allergic asthma.
"While we studied patients with allergic asthma," he continues, "this research opens the door for the development of new treatments not only for this population, but for those diagnosed with severe asthma as well."
The researchers found that blocking this protein in the lungs with an antibody reduces inflammation and provides resistance to allergens for people with mild allergic asthma.
For the study, a phase II clinical trial group supported by the Allergy, Genes and Environment Network, the Clinical Investigator Collaborative, recruited 31 patients over five sites across Canada.
After a monitoring period of 12 weeks, the researchers found significantly reduced baseline inflammation in participants receiving the antibody treatment, compared with those taking a placebo.
The results of the trial are published in the New England Journal of Medicine and were presented at the American Thoracic Society conference in San Diego, CA.
Previous clinical trials examining antibodies as asthma treatments
The McMaster team also conducted a trial in 2009 that investigated the use of the antibody mepolizumab to treat asthmatics with a persistent kind of airway inflammation called eosinophils.
- Antibodies are proteins produced by the immune system when it detects harmful substances (antigens)
- Each type of antibody is unique and defends against one specific type of antigen
- Autoimmune disorders are when the immune system mistakenly produces antibodies in response to healthy tissue.
That trial found that patients receiving mepolizumab became less reliant on using prednisone - a drug associated with side effects including diabetes, weight gain and bone loss - than a control group.
In 2013, the New England Journal of Medicine published the findings of another phase II clinical trial looking into using a monoclonal antibody to control asthma.
In that trial, 52 participants with moderate-to-severe asthma received weekly injections of the antibody - called dupilumab - in addition to their regular asthma inhalers. These patients experienced significant improvements in peak flow, asthma symptoms and control, compared with 52 participants who received a placebo.
This antibody works by blocking two cytokines - interleukin-4 and interleukin-13 - in order to prevent activation of the Th2 immune response that is associated with asthma.
This trial also noted some side effects, such as nasopharyngitis, nausea and headache, but they were not considered severe.