New treatments for asthma

Abstract

It has proved to be very difficult to develop new classes of antiasthma therapy, partly because existing drugs, and particularly inhaled corticosteroids are so effective. The only new class of drug developed in 25 years have been the antileukotrienes which are less effective than inhaled corticosteroids. There is a need to develop new treatments for asthma, since patients with severe asthma are not well controlled on doses of corticosteroids that are safe, and there is a problem of poor compliance with existing inhaler therapy. Several drugs are now in development for asthma. New bronchodilators have been difficult to develop as new drugs are less effective than β 2-agonists and have more side effects. Mediator antagonists have proved disappointing as so many mediators are involved in asthma. Inhibitors of cytokines, such as interleukin (IL)-5, IL-4 and eotaxin, which may inhibit eosinophilic inflammation, are now in clinical development. Other approaches include more selective immunomodulation, anti-IgE antibodies, adhesion molecule blockers and kinase inhibitors. Preventive treatments in the future may include drugs that alter the immune abnormalities in atopy by stimulating a protective Th1 immunity. A cure for asthma does not seem likely in the near future.