Late Breaking Abstract - Efficacy of oral prednisolone in patients with stable severe eosinophilic asthma (SEA) treated with Mepolizumab

Background: Mepolizumab and prednisolone have overlapping anti-inflammatory effects so the clinical effects of prednisolone might be absent in stable patients on treatment with mepolizumab. Methods: We tested this hypothesis in a randomized, double-blind, placebo-controlled, crossover trial of prednisolone (0.5mg/kg/day for 2 weeks) after ≥12 weeks of mepolizumab. Results: Blood and sputum eosinophil count decreased post-prednisolone (-0.02x109/L, p=0.003; -10.5x109/L, p=0.004); differences compared to placebo were -0.02x109/L (p Conclusions: In patients with SEA treated with mepolizumab, prednisolone has no significant effects on symptoms or QoL but improves FEV1 and small airway function and reduces FeNO, potentially reflecting suppression of persisting IL-4/IL-13 pathways.