analyses of the distribution of changes in FVC in the INPULSIS® trials and FVC changes in the open-label extension trial INPULSIS®-ON in subgroups of patients based on whether patients had shown an improvement or no decline in FVC in INPULSIS®. Analyses were descriptive.Based on the annual rate of change in FVC, 158 of 638 patients (24.8%) treated with nintedanib and 38 of 423 patients (9.0%) treated with placebo had an improvement/no decline in FVC in the INPULSIS® trials. In patients whose FVC improved/did not decline, median (interquartile range) improvements in FVC at week 52 were 76.5 (31-152) mL and 57.5 (31-103) mL in the nintedanib and placebo groups, respectively. Changes in FVC from baseline to week 48 of INPULSIS®-ON were similar in patients whose FVC improved or declined in the preceding INPULSIS® trial.In the INPULSIS® trials, treatment with nintedanib resulted in a greater proportion of patients with IPF showing an improvement/no decline in FVC compared to taking placebo. Mechanisms underlying improvement in FVC in patients with IPF are unknown.