Abstract
BACKGROUND: The combination of an inhaled corticosteroid (ICS) and long-acting β-agonist (LABA) (ICS/LABA) has shown superiority in improving lung function (FEV(1)) compared with an ICS alone. The clinical effect of a ICS/LABA combination depends on the fine-particle fraction and the pulmonary deposition. OBJECTIVE: We sought to compare the efficacy of 2 combinations of an ICS and LABA, namely, fluticasone propionate (FP) and formoterol (FORM) (FP/FORM) and fluticasone furoate (FF) and vilanterol (VI) (FF/VI), in asthmatic adolescents with chronic bronchial obstruction. METHODS: FP/FORM (125 μg/5 μg, 2 doses twice daily via the k-haler [Mundipharma, Cambridge, UK]) and FF/VI (92 μg/22 μg, once daily via the Ellipta inhaler [GlaxoSmithKline]) were administered to adolescents aged 12 to 17 years who required regular antiasthmatic medication and had a ratio of FEV(1) to forced vital capacity (FEV(1)/FVC) less than -1.65 SD in a 2-sequence, 16-week crossover trial. The primary efficacy end point was change in FEV(1) compared with baseline. Secondary end points were FEV(1)/FVC ratio, maximal expiratory flow at 50% of the FVC, impulse oscillometry indices respiratory resistance at 5 Hz (R5), difference between R5 and respiratory resistance at 20 Hz (R20), area of reactance, and Asthma Control Test score. RESULTS: Both ICS/LABA combinations resulted in a significant improvement in FEV(1) and maximal expiratory flow at 50% of the FVC z scores without any significant difference between FP/FORM and FF/VI, with 40% of patients with either treatment achieving a normal prebronchodilator FEV(1)/FVC z score. Neither area of reactance nor difference between R5 and R20 improved significantly with either treatment. CONCLUSION: Both ICS/LABA combinations demonstrated significant improvements in FEV(1)z score. More than one-third of the asthmatic adolescents with prolonged bronchial obstruction achieved a normal prebronchodilator FEV(1)/FVC ratio.