CAMP: Inhaled steroids improve asthma, but progress wanes if therapy stopped

May 2006

MIAMI BEACH, Fla. — The most recent data from the Childhood Asthma Management Program (CAMP) reinforces earlier results that inhaled corticosteroids improve asthma symptoms, however, the effect is not long-lasting if patients do not remain on therapy, according to Robert C. Strunk, MD.

“Budesonide improves airway responsiveness during treatment, but the effect wanes rapidly when the medication is stopped,” Strunk said here at the 2006 Annual Meeting of the American Academy of Asthma, Allergy and Immunology. “We feel that the implications of our findings are that the relative benefit of inhaled corticosteroids in improving airway responsiveness clearly requires continued use of inhaled corticosteroids. Those with more atopy and more abnormal pulmonary function at baseline are at the greatest risk of increased airway responsiveness, and this was associated with increased asthma morbidity and appears to be the best candidates for those children who should be on inhaled steroids on a long-term basis,” said Strunk, who is Donald Strominger Professor of Pediatrics, Washington University School of Medicine, St. Louis.

What’s CAMP

CAMP, the longest and largest controlled study of asthma treatment for children, involved more than 1,000 children between the ages of 5 and 12 with mild to moderate asthma. The children were randomly assigned to receive either budesonide, an inhaled corticosteroid; nedocrimil, a non-steroid anti-inflammatory medication; or a placebo. All children were also provided with a -agonist for use, as needed, to relieve symptoms. Earlier data showed that inhaled corticosteroids provide superior asthma control.

After testing and randomization, there was a treatment phase of four to six years with three visits per year. Afterward, patients discontinued the study medicine followed by a short transition phase of four months with two visits to look at early effects of discontinuation of study medicine.

“We then re-enrolled children into a continuation study for a four-year follow-up when treatment was directed by the child’s physician,” he said, adding, “we successfully enrolled 90% of the original cohort in the continuation follow-up and during this interval missed only 2% of the visits.”

New data

Strunk shared some results from the second part of this study. More than 90% of the planned methacholine challenges were completed, and the mean time of follow-up for both CAMP and the continuation was 8.6 years during which they conducted 8,100 methacholine challenges, according to Strunk.

“Overall, there was improvement in airway responsiveness through time in all three treatment groups,” he said. “There was only one significant difference between either of the treatments and the placebo, that being between budesonide and placebo at the end of the study, however, this effect waned rapidly and at the end of washout, a little over two years later, there was no advantage to budesonide.”

At the end of continuation, the effects of neither budesonide nor nedocrimil differed from placebo. “Thus we conclude that budesonide improves airway responsiveness throughout prolonged treatment, but the benefits of prolonged treatment are lost rapidly upon discontinuation. Nedocrimil does not affect airway responsiveness either during treatment or after discontinuation,” he said.

The researchers also found some gender differences in airway responsiveness. From ages 5 to 11, boys and girls have an improvement on airway responsiveness that is generally similar. However, from age 11 to 18, only male patients continue to improve.

In addition, they found that children who experienced urgent care visits had greater airway responsiveness, regardless of age group, and increased airway responsiveness is associated with ongoing symptoms and urgent care visits even in older children, according to Strunk.

For more information:

• Strunk RC. Airway responsiveness in children with mild to moderate asthma: changes with time and treatment. Presented at: 2006 Annual Meeting of the American Academy of Asthma, Allergy and Immunology; March 3-7, 2006; Miami Beach, Fla.