Patient factors predict asthma therapy response

Specific patient characteristics may help guide doctors in selecting the asthma medication most likely to lead to favorable responses in children with mild-to-moderate persistent asthma, a team of U.S. researchers reports.

Children with low lung function levels and signs of allergic inflammation appear to be best treated with an inhaled corticosteroid (ICS), while others could be treated with another class of drugs called leukotriene receptor antagonists (LTRA), which are taken orally.

"This study is a major step forward in identifying ways that we can use patient characteristics and specific laboratory tests to select a medication," Dr. Stanley J. Szefler noted in comments to AMN Health.

"This type of information helps get the patient to the medication that is most likely to be effective in the shortest period of time, as compared to a trial and observation approach," he added.

The findings come from a study conducted by Szefler and colleagues at National Jewish Medical & Research Center in Denver, Colorado and the National Heart, Lung, and Blood Institute in Bethesda, Maryland, published in the Journal of Allergy and Clinical Immunology.

The investigators administered the ICS fluticasone (Flovent Diskus; GlaxoSmithKline) or the LTRA montelukast (Singulair; Merck) for 8 weeks to 126 asthmatic children 6 to 17 years of age. After 8 weeks, the patients were switched over to the other drug.

"This is the first study of this type performed in children where each child received each asthma medication at separate times," Szefler said. "We were able to clearly observe the response to each medication and to associate features of the patient - namely, (lung) function and markers of allergic inflammation - associated with a good response."

At the end of the 16-week trial, 17 percent of subjects had responded to both medications with a 7.5 percent or better improvement in lung function, the team reports. Conversely, 23 percent of the children improved only with fluticasone, and 5 percent only with montelukast. Fifty-five percent did not improve with either medication.

A favorable response to fluticasone was associated with higher levels of markers of allergic inflammation and lower levels of lung function at the start of the study. In contrast, a good response to montelukast was generally only associated with younger age and shorter duration of asthma.

Based on these findings "children who have reduced pulmonary function or high levels of markers indicating allergic inflammation should receive ICS therapy, whereas those without these features could receive a therapeutic trial of either ICS or LTRA with an assessment of response," the researchers conclude.

SOURCE: Journal of Allergy and Clinical Immunology, February 2005.