- BACKGROUND: We explored the impact of FVC decline on subsequent FVC decline and mortality in the INPULSIS trials of nintedanib in patients with IPF and their open-label extension, INPULSIS-ON. METHODS: Changes in FVC and mortality between weeks 24 and 52 of the INPULSIS trials were assessed in patients with an increase/no decline in FVC % predicted and with declines in FVC <10% and ≥10% predicted from baseline to week 24. Changes in FVC and mortality in the first year of INPULSIS-ON were assessed in patients treated with nintedanib in the preceding INPULSIS trial who did and did not have a decline in FVC ≥10% predicted at week 52. RESULTS: The proportion of placebo-treated patients with decline in FVC ≥10% predicted between weeks 24 and 52 of INPULSIS was similar in patients with increase/no decline in FVC and with decline in FVC ≥10% predicted between baseline and week 24 (20.5% and 18.9%, respectively). Mortality between weeks 24 and 52 of INPULSIS was higher in patients with FVC decline ≥10% predicted than <10% predicted between baseline and week 24 (13.2% vs 3.8%). Among nintedanib-treated patients in INPULSIS who had decline in FVC ≥10% versus <10% predicted at week 52, 34.0% versus 21.4%, respectively, had decline in FVC ≥10% predicted in the first year of INPULSIS-ON. Mortality in the first year of INPULSIS-ON was 21.3% vs 5.7% in these groups, respectively. CONCLUSIONS: Decline in FVC did not predict FVC decline but was associated with mortality in patients with IPF.