Effect of erdosteine in moderately severe COPD patients

Background: In RESTORE study (528 pts, GOLD II-III) erdosteine 300 mg bid added to usual COPD therapy reduced exacerbation rate by 17.1% (p=0.01) and lowered duration by 24.6% (p=0.02). Aim and Objective: To assess the effect of erdosteine on exacerbation rate and time to first exacerbation in moderately severe COPD spirometrically defined patients. Methods: Exacerbations were defined as a symptomatic worsening requiring change in regular medication or health care resources utilization. In this post-hoc analysis we consider 254 GOLD II (2011 definition) patients. The frequency of exacerbations per patient/year (12 months treatment) were analyzed non-parametrically (Wilcoxon rank sum test), the time free from first exacerbation using the log-rank test (Kaplan–Meier). Results: Compared to more severe patients, GOLD II patients had similar baseline characteristics but higher FEV1 and FVC values. After 1-year treatment in GOLD II subgroup, 74 exacerbations (57.8%) have been registered in the placebo vs. 53 (42.1%) in the erdosteine group. Erdosteine reduced the exacerbation rate by 47% (OR: 0.530, 95% CI 0.322-0.872, p= 0.017). This result was independent from individual variables or background treatment including ICS use. Additionally erdosteine increased the time to first exacerbation (Median time: 183 vs. 167 days Δ% +7.1 vs placebo P>0.001). Conclusions: Erdosteine significantly reduced the exacerbation rate and increase the time to first exacerbation. Although the time to first event was a less sensitive marker in the total study population it improved significantly in this subgroup with a large benefit on exacerbation rate, suggesting a potential role of erdosteine in moderately severe COPD.