Randomized, placebo-controlled study of a selective PDE4 inhibitor in the treatment of asthma

Background: Phosphodiesterase-4 (PDE4) inhibitors have potential utility as a new therapeutic approach to improving symptoms and pulmonary function in asthma and COPD. This study evaluated the efficacy and safety of MK-0359, a selective and potent oral PDE4 Inhibitor, in chronic asthma.

Methods: Adults (N=88) with > or =1 year asthma history and an FEV(1) 50-80% predicted were randomized to double-blind treatment with MK-0359 (15mg/day) or placebo for 14 days, then crossed-over to the Other treatment for 14 days. The primary endpoint was the change from baseline in FEV(1) at the end of each 2-week treatment period. Secondary and Other endpoints included the changes from baseline in Daytime asthma symptom score, Nighttime asthma symptom score, Total daily beta-agonist use (puffs/day), AM and PM peak expiratory flow (PEF) and overall asthma-specific quality-of-life. Safety and tolerability were assessed by clinical adverse experiences.

Results: MK-0359 significantly improved the primary endpoint (versus placebo): the least-squares mean difference in change from baseline in FEV(1) (L) was 0.09L (95% CI 0.01, 0.18). Endpoints of Daytime asthma symptom score, Nighttime asthma symptom score, Total daily beta-agonist use, AM PEF, PM PEF, and quality-of-life were also significantly improved. Nineteen patients (24.1%) on MK-0359 and 8 patients (10.4%) on placebo reported gastrointestinal clinical adverse experiences. Serious gastrointestinal clinical adverse experiences were reported in 3 patients while receiving MK-0359.

Conclusion: Over a 14-day treatment period, the oral PDE4 Inhibitor MK-0359 improved lower airway function, symptoms and rescue medication use in chronic asthma, although at the expense of gastrointestinal adverse experiences. (Clinical trial registry number: NCT00482898.).