Late Breaking Abstract - Azithromycin for acute COPD exacerbations requiring hospitalization – the BACE trial results

Background: Azithromycin (AZ) prevents acute exacerbations in COPD (AECOPD); however, the optimal dose, treatment duration and target population are yet to be defined. Methods: A multicenter, randomized, doubleblind, placebo-controlled trial investigated the effect of AZ initiated within 48h of hospital admission for an AECOPD (500mg/day for 3days) and subsequently administered for 3 months (3m) (250mg/2days). Patients were followed-up for 9m, including 6m after AZ withdrawal. Time-to-treatment failure (TF) within 3m was evaluated as novel primary endpoint, with TF defined as the composite of treatment intensification with medication (TI) or step-up in hospital care or readmission for respiratory reasons (SHR) or all-cause mortality. Results: 301 COPD patients were randomized (1:1) to receive AZ (n=147) or placebo (n=154) on top of a standard treatment with corticosteroids and antibiotics. The TF rate at 3m was 49% in the AZ arm and 60% in the placebo arm (HR=0.73; 95%CI 0.53-1.01; p=0.053 for time-to-TF and ∆=-0.24; 95%CI -0.48-0.00; p=0.040 for cumulative TF). TI, SHR and mortality within 3m were 47% vs 60% (p=0.027), 13% vs 28% (p=0.002) and 2% vs 4% (p=0.507) respectively. Significance was lost 6m after AZ withdrawal (Fig1). Conclusion: AZ for AECOPD requiring hospitalization may significantly reduce TF during the highest risk period. These benefits are lost 6m after the discontinuation of AZ.