Lung function parameters in omalizumab responder patients: An interesting tool?

Abstract

Omalizumab, an anti-IgE antibody, is used to treat patients with severe allergic asthma. The evolution of lung function parameters over time and the difference between omalizumab responder and nonresponder patients remain inconclusive. The objective of this real-life study was to compare the changes in forced expiratory volume in 1second (FEV1) of omalizumab responders and nonresponders at 6months. A multicenter analysis was performed in 10 secondary and tertiary institutions. Lung function parameters (forced vital capacity (FVC), pre- and postbronchodilator FEV1, residual volume (RV), and total lung capacity (TLC) were determined at baseline and at 6months. Omalizumab response was assessed at the 6-month visit. In the omalizumab responder patients, lung function parameters were also obtained at 12, 18, and 24months. Mean prebronchodilator FEV1 showed improvement in responders at 6months, while a decrease was observed in nonresponders (+0.2±0.4L and -0.1±0.4L, respectively, P<.01). After an improvement at 6months, pre- and postbronchodilator FEV1 remained stable at 12, 18, and 24months. The FEV1/FVC remained unchanged over time, but the proportion of patients with an FEV1/FVC ratio <0.7 decreased at 6, 12, 18, and 24months (55.2%, 54.0%, 54.0%, and 44.8%, respectively, P<.05). Mean RV values decreased at 6months but increased at 12months and 24months (P<.05). Residual volume/total lung capacity (RV/TLC) ratio decreased at 6months and remained unchanged at 24months. After omalizumab initiation, FEV1 improved at 6months in responder patients and then remained stable for 2years. RV and RV/TLC improved at 6months.