Asthma
Asthma is a recurring condition in which certain antigen-based triggers (such as pollens, dust or cold air) cause the airways to constrict, become inflamed, and are lined with excessive amounts of mucous, resulting in restricted breathing. These triggers also cause certain immune cells in the airway to release chemical signals that lead to inflammation (see Figure 1). It is estimated that as many as 300 million people of all ages, and all ethnic backgrounds, suffer from asthma world wide. It is estimated that there are 22.5 million people living with asthma in the U.S. Asthma is the most common chronic disease of childhood, affecting an estimated 4.8 million US children (GINA 2004; Adams and Marano 1995; Centers for Disease Control and Prevention 1995).
The primary goals of asthma therapy are to prevent chronically recurring and troublesome symptoms (coughing, breathlessness), maintain near normal pulmonary function and activity level, and reduce the severity and frequency of recurrent exacerbations. Asthma medications are categorized in two general classes: long-term control medications taken daily to achieve and maintain control of persistent asthma and quick-relief rescue medications taken to provide prompt reversal of acute airflow obstruction and relief of bronchoconstriction. The pharmacologic agents most commonly used to treat chronic asthma and exacerbations include inhaled corticosteroids (ICS), short-acting and long-acting β2 agonists (SABA and LABA, respectively), combination ICS/LABAs, antileukotrienes, anticholinergics and anti-IgE monoclonal antibodies. Beta2-agonists are typically used to relax smooth muscle cells of the airway for acute relief of airway constriction and inhaled corticosteroids for the treatment of underlying inflammation.
Although the use of ICS and LABA have dramatically improved asthma care, a significant percentage of patients, approximately one out of four, are not well-controlled, and continue to experience asthma exacerbations despite ongoing therapy. More specifically, 20% of patients are not well controlled (as defined by GINA [Global Initiative for Asthma]) on ICS/LABA combinations and 35% of patients are not well controlled on ICS therapy alone. The 2003 introduction of an injectable monoclonal antibody targeting IgE, has provided a defined group of poorly-controlled asthma patients a new treatment option with a differentiated mechanism of action; however, new therapies are needed for patients living with asthma who are not well-controlled with existing pharmacologic treatments.
Asthma results from a dysregulated, hyperresponsive immune system. Some immune cells in allergic asthmatics respond agressively to foreign allergens with the release of interleukins 4 and 13, two key mediators that initiate a cycle of inflammation in the lung. AEROVANT™ is an IL4Ra receptor antagonist that blocks the inflammatory effects of interleukins-4 and -13 (IL-4 and IL-13), thereby promoting a more balanced immune response.
Do you have uncontrolled asthma? The American Lung Association has a questionnaire that can help you and your doctor in the diagnosis of uncontrolled asthma: Go to www.asthmacontrol.com. For more information on asthma, contact the American Lung Association (www.lungusa.org), the National Heart, Lung and Blood Institute (www.nhlbi.org), the American Asthma Foundation
(www.americanasthmafoundation.org) or the Global Initiative for Asthma (www.ginasthma.com).