Background Nintedanib, an intracellular inhibitor of tyrosine kinases, is in development for the treatment of idiopathic pulmonary fibrosis (IPF). The INPULSIS™ trials were two replicate randomised, double-blind, placebo-controlled, 52-week Phase III trials that assessed the efficacy and safety of nintedanib 150 mg twice daily in patients with IPF. The primary endpoint was the annual rate of decline in forced vital capacity (FVC), which was significantly reduced in the nintedanib group compared with placebo in both trials.
Aim To assess the impact of baseline FVC on the effect of nintedanib on rate of decline in FVC.
Methods A pre-specified subgroup analysis of patients with baseline FVC >70% versus ≤70% of predicted value was undertaken using pooled data from both trials.
Results 700 patients (nintedanib 431, placebo 269) had baseline FVC >70% predicted and 361 patients (nintedanib 207, placebo 154) had baseline FVC ≤70% predicted. For patients with a baseline FVC >70% predicted, mean age was 67.4 years, 76.9% were male, 55.7% were White and mean carbon monoxide diffusion capacity (DLCO) was 4.0 mmol/min/kPa. For patients with a baseline FVC ≤70% predicted, mean age was 65.5 years, 83.9% were male, 60.4% were White and mean DLCO was 3.6 mmol/min/kPa. There was no significant treatment by subgroup interaction: the difference in adjusted annual rate of decline in FVC between the nintedanib and placebo groups was comparable in both subgroups.
Conclusion A subgroup analysis of pooled data from the INPULSIS™ trials showed that nintedanib 150 mg twice daily slowed the decline in lung function in patients with IPF, independent of severity of lung function impairment at baseline.