New Treatment: A Vaccine for Asthma

Immunoglobuline (IgE) plays a major role in the release of symptom causing chemicals in asthma. A genetically engineered monoclonal antibody vaccine known as anti-IgE is currently undergoing human trials. Monoclonal antibodies are tiny proteins that are produced by white blood cells involved in immune reactions. These antibodies target substances such as IgE and neutralize it. Unlike conventional treatments such as corticosteroids that reverse inflammation after it has occurred, anti-IgE aims to curtail the inflammatory process before it starts.

The results of the early trials of anti-IgE (rhuMAb-E25) are encouraging with no significant side effects reported to date. Anti-IgE should also be helpful in allergic rhinitis and possibly food allergies.

New Medications

New and modified asthma medications are likely to improve treatment of bronchial asthma. Several medications already in general use in Canada and Europe are to be marketed in the United States in the near future. Many other medications are being investigated.

Anti-leukotrienes

Additional anti-leukotriene medications are likely to join montelukast ,zafirlukast, and zileuton, which are currently in use in the United States. An agent, MK-0591, which inhibits the action of an enzyme (5-lipoxygenase) involved in the formation of leukotrienes, has been found to be effective and appears promising. Verlukast and pranukast, two agents which block the action of leukotrienes after they are produced, also appear effective.

Mediator Antagonists

Asthma mediators are irritating chemicals that are either stored within allergy cells (mast cells, eosinophils) or produced when these cells are activated. These substances produce many changes that lead to inflammation of the bronchial tubes. Examples include histamine, leukotrienes, prostaglandins, cytokines, thromboxanes, and platelet-activating factor (PAF). Additional mediator antagonists which would have anti-inflammatory properties are currently under development. Two inhibitors of PAF (WEB-2086, L-659), have already been shown to reduce inflammation in bronchial asthma and appear promising.