New approaches to asthma treatment
Earlier last month, I attended an international conference on clinical and research advances in asthma and allergic diseases. There are some exciting new prospects on the horizon for asthma treatment. In this entry, I would like to provide a summary of a few of these candidates and how they compare to currently existing therapies for asthma.
Asthma treatment - past and present
In a recent entry on theophylline and its utility in asthma treatment, I provided a snapshot of the past decades and evolution of approaches to asthma therapy. The key point: until about 15 years ago, asthma treatment was effective but not very sophisticated.
The major advance of using inhaled steroid medication (asthma inhalers) was not that it specifically targeted the primary causes of airway inflammation in asthma, but rather that it delivered medicine to "where the action is," as opposed to steroid pills, which had to travel through the blood stream, thus potentially causing side effects in the rest of the body. The advent of long acting ‘beta-agonists' (e.g. Serevent (salmeterol), Foradil (formoterol)) were based on the action of albuterol, which was short-acting. Their function is essentially the same - like the difference between ibuprofen and naproxen.
Recent research, primarily using animal asthma models, has greatly expanded our understanding of the cellular basis of airway swelling (inflammation) in asthma and the ways that inflammatory cells talk to each other to start and perpetuate asthmatic inflammation in the lungs.
Some new therapies are still in development that interfere with specific pathways in the way that immune cells ‘talk' to each other and cause asthmatic inflammation. This includes specific antibodies against Interleukin-5 (which promotes growth and activity of a major cell in asthma - the eosinophil), and anti-Interleukin-4 receptor, which prevents immune cells from responding to the protein Interleukin-4, which propagates ‘allergic' antibodies. While these treatments are in development, other such ‘targeted' therapies are available such as Xolair (omalizumab), which provides antibodies against immunoglobulin E (IgE).
Targeting early development of asthma
Another significant and recetly hot area of research regards understanding the early steps in the development of the immune system in asthma. Several large research studies have shown that there is a link between the environment in which children grow up and the risk of developing asthma and allergies. These studies have found a protective effect of growing up in a farming environment with respect to developing allergies and asthma. This effect may be due to early childhood exposure to stables and animal dusts. Researchers have harnessed this idea and tried to mimic this exposure by chemically linking common allergens to certain bacterial products that are commonly found in animal dust. This fascinating approach seeks to "educate" the immune system in a different direction than one in which allergies would develop. While none of these treatments are ready for prime time, there are several ongoing trials in asthmatics that directly address this opportunity.
While the mainstays of current standard asthma treatment are well established, as they have been for about 15 years, recent scientific advances hold great promise for new treatments that not only target specific points in the abnormal lung response in asthma but may be more tailored to the individual patient with asthma. It is an exciting time and both patients and providers should keep their ears to the ground as new therapies are developed to add to current asthma treatments.
Published On: April 02, 2008