Firestone Study Demonstrates New Treatment for Severe Asthma
Researchers from the Firestone Institute for Respiratory Health at St. Joseph’s Healthcare Hamilton, together with colleagues at other partnering institutions, have developed a new method to treat severe asthma. In a study of over 200 participants with severe asthma, the new treatment was shown to have improved asthma symptoms and lung function, while reducing the need for corticosteroids (prednisone) by up to 70%.
According to Statistics Canada, 8.1% of Canadians aged 12 or older – approximately 2.4 million people – have been diagnosed with asthma. Of that, approximately 25% are considered to be severe cases of asthma.
Current treatments for severe asthma often include high doses of prednisone or other corticosteroids to control exacerbations. Reducing the need for corticosteroids with alternative treatments is preferable, since these medications are associated with serious side effects from prolonged use – including multi-organ toxicities and immunosuppression.
Dr. Parameswaran Nair, staff respirologist at St. Joseph’s Healthcare Hamilton and Professor of Medicine at McMaster University, along with a team of researchers found that an antibody called dupilumab is effective in treating severe asthma in place of high doses of prednisone. The results were published in the New England Journal of Medicine, one of the world’s most influential medical publications.
Dr. Nair (right) in the Sputum Lab at St. Joe's
Researchers sought participants who had been using prednisone to treat severe asthma for at least 6 months prior to the study. During the 24 week trial, patients received either dupilumab or a placebo to supplement their prednisone treatment. The prednisone dose was gradually reduced during weeks 4 to 20, and maintained at a low level for the final 4 weeks.
“The ability of dupilumab to increase lung function as markedly as it did in this study, even in the face of [prednisone] withdrawal, indicates that it appears to be inhibiting key drivers of lung inflammation,” the researchers noted.
Dupilumab works to treat asthma by blocking two specific proteins (called interleukins) that are associated with inflammation of the airways. The technique was based on Dr. Nair’s past work out of the Firestone Institute, previously published in the New England Journal of Medicine in 2009 and in 2017.
Unlike the previous studies, dupilumab was shown to be effective regardless of patients’ eosinophil levels – eosinophils are a type of white blood cell involved with the production of various protein signals. High eosinophil levels are directly linked to an increased risk of severe asthma.
“Ultimately, our goal is to find new treatment pathways that allow us to circumvent the use of [prednisone],” said Dr. Nair. “Since dupilumab showed a significant improvement on asthma control regardless of eosinophil levels, we may be able to use this treatment for a wider range of patients than we previously thought possible.”
Researchers also noted that the new treatment was not associated with any serious side effects.
Dr. Nair and his team presented the details of their study at the American Thoracic Society’s international conference in San Diego this past week. There, researchers and clinicians from around the world gathered to discuss respiratory illnesses and the latest breakthroughs in treatment.
“This work highlights the clinical and research excellence in pulmonary diseases that exists at St Joseph's and the Firestone Institute,” explained Dr. Jack Gauldie, Vice President (Research) at St. Joseph’s Healthcare Hamilton. “Dr. Nair is one of the world’s best clinicians in the field of severe asthma and his studies on modification of immune regulation, targeting two important immune factors, bring an immense impact directly from the lab to the patient in managing this difficult and dangerous form of asthma. We are immensely proud of these advances in pulmonary medicine.”
For more information, visit the Firestone Institute for Respiratory Health.