Canadian study finds potential antibody treatment for mild asthma
Marlene Leung, CTVNews.ca
Published Tuesday, May 20, 2014 11:17AM EDT
Last Updated Tuesday, May 20, 2014 12:52PM EDT
Canadian researchers have successfully tested an antibody that may lead to an improvement in the quality of life for asthma patients by reducing inflammation in the lungs.
In a new study, published Tuesday in The New England Journal Medicine, the researchers found that blocking a specific protein in the lungs with the antibody AMG 157 relieved baseline inflammation, as well as provided protection against allergens for those patients with mild allergic asthma.
Patients with allergic asthma are typically treated with bronchodilators or corticosteroids that they inhale. However, the findings of the new study may eventually lead to an antibody treatment for those patients with mild allergic asthma who have problems using inhalers or steroid-based medications, the study's authors say.
Dr. Paul O'Byrne, executive director of the Firestone Institute of Respiratory Health in Hamilton, Ont. and the study's co-lead author, said that the research team discovered that the cells that line the airways in the lungs are constantly producing a specific protein, called thymic stromal lymphopoietin (TSLP), which causes inflammation.
"What our study showed for the first time is that if you give an antibody that blocks the action of this particular protein, TSLP, you can very effectively block the airway’s responses to the inhaled allergens," he told CTV News.
O'Byrne said the results show that TSLP plays a key role in producing asthmatic responses. They also show that by potentially blocking TSLP, researchers may be able to improve the quality of life for asthmatic patients in the long term.
The small double-blind, controlled study recruited 31 patients with mild allergic asthma from five different sites across Canada.
The patients were randomly assigned to receive either three monthly doses of AMG 157 or placebo, which were both administered intravenously. The researchers monitored the patients and also exposed them to a series of allergens to test the effect of the antibody on their asthma.
O'Byrne said the patients experienced no major side-effects and appeared to have tolerated the antibody very well.
After three months of monitoring, the researchers found that the antibody significantly reduced baseline inflammation in the lungs and protected the participants against inhaled allergens when compared to placebo.
Surprisingly, the researchers found that all of the patients who received the antibody had reduced inflammation of the lungs even before the allergen was introduced, he added.
"So they got better even before we gave them the allergen to inhale," he said. "By giving this antibody we are able to block a protein that begins the inflammation and starts the whole process off. So it's what we call 'upstream of the inflammatory response,' and by blocking that we are able to intervene before the inflammation develops."
Dr. Sven-Erik Dahlen, director of Karolinska Institutet's Centre for Allergy Research in Sweden, said that the findings can affect the direction of asthma research, with future studies paying closer attention to TSLP.
"This is really a new kid that has entered the asthma block," he said.
The study's authors said that while the study only looked at patients with mild allergic asthma, the results could lead to new types of treatments for more severe forms of asthma.
Study participant Luke Janssen, 52, was first diagnosed with asthma when he was 25.
He said he gets asthma attacks whenever he exercises or is exposed to certain allergens from dust mites and cats.
While he does not know if he received the antibody or the placebo, he said his symptoms improved over the course of the study, leading him to suspect that he was on the medication.
He said he noticed an "amazing" difference in his breathing once he started his treatment in the study.
"It's like breathing through a couple of straws… it just becomes very oppressive," he told CTV News. "Then you take the straws out of your mouth and breathe normally, it was a feeling of relief. A full breath, it was an amazing feeling."
With files from CTV's Medical Specialist Avis Favaro and Senior Producer Elizabeth St. Philip