The Predicting Response to Inhaled Corticosteroid Efficacy (PRICE) trial

Background: Although guidelines recommend anti-inflammatory therapy for persistent asthma, recent studies suggest that 25% to 35% of patients with asthma may not improve lung function with inhaled corticosteroids. Objective: To evaluate potential biomarkers of predicting short-term (6-week) response to inhaled corticosteroid with subsequent evaluation of responders and nonresponders to asthma control over a longer interval (16 additional weeks). Methods: Eighty-three subjects with asthma off steroid were enrolled in this multicenter study. Biomarkers and asthma characteristics were evaluated as predictors of inhaled corticosteroid response over a 6-week trial for changes in FEV₁ and methacholine PC₂₀. After this, an additional 4-month trial evaluated asthma control. Results: Although multiple baseline predictors had significant correlations with improvements for short-term inhaled steroid success, the only strong correlations (r ≥ ± 0.6) were albuterol reversibility (r = 0.83; P < .001), FEV₁/forced vital capacity (r = -0.75; P < .001), and FEV₁ % predicted (r = -0.71; P < .001). Dividing the subjects in the short-term inhaled steroid trial into responders (>5% FEV₁ improvement) and nonresponders (≤5%) determined the longer-term need for steroids. For the nonresponders, asthma control remained unchanged whether inhaled corticosteroids were continued or were substituted with a placebo (P = .99). The good short-term responders maintained asthma control longer-term only if maintained on inhaled steroids (P = .007). Conclusion: The short-term response to inhaled corticosteroids with regard to FEV₁ improvement predicts long-term asthma control. Clinical implications: The decision to use long-term inhaled steroids could be based on a short-term trial. Different therapeutic strategies would need to be established for nonresponders.