Background: Nintedanib is a multi-kinase inhibitor approved for idiopathic pulmonary fibrosis (IPF); however, its efficacy and safety for patients with IPF and restricted pulmonary function remain unclear. Therefore, the objective of this study was to determine the efficacy and safety of nintedanib for patients with IPF and forced vital capacity (FVC) ≤ 50%.
Methods: This was a multi-center retrospective study performed by the Okayama Respiratory Disease Study Group. Patients were allocated into FVC ≤ 50% and FVC > 50% groups based on their predicted FVC. The primary endpoints were FVC changes from baseline after 6 and 12 months.
Results: 45 patients were eligible for the study. 18 patients had FVC ≤ 50%, and 27 patients had FVC > 50%. Overall, 31 and 19 patients underwent pulmonary function tests at 6 and 12 months after initiating nintedanib, respectively. FVC changes from baseline at 6 and 12 months after initiating nintedanib were comparable between the two groups. Adverse events were seen in all patients, and the rates of patients who discontinued nintedanib were also comparable (38.9% vs. 37.0%, p = 1.000). Multiple regression analysis showed that age and forced expiratory volume in 1 second (FEV1)/FVC were negatively correlated with changes in FVC at 6 months after initiating nintedanib.
Conclusions: Our data suggest that nintedanib can be a useful agent for IPF patients, including those with a low FVC, and that age and FEV1/FVC are predictive markers for changes in FVC following nintedanib treatment.