Background: Nintedanib is an approved therapy for idiopathic pulmonary fibrosis (IPF). Some patients treated with nintedanib experience weight loss. Exploratory data suggest that low body mass index or weight loss are associated with worse outcomes in patients with IPF. We investigated whether BMI at baseline or weight loss over 52 weeks was associated with FVC decline, or influenced the effect of nintedanib, in patients with IPF.
Methods: Using pooled data from the two INPULSIS trials, we analysed the rate of decline in FVC (mL/yr) over 52 weeks in patients treated with nintedanib and placebo in subgroups by baseline BMI (< 25; ≥25 to < 30; ≥30 kg/m2) and by weight loss over 52 weeks (≤5; > 5%) using random coefficient regression.
Results: In the placebo group, the mean rate of FVC decline over 52 weeks was numerically greater in patients with lower baseline BMI (- 283.3 [SE 22.4], - 207.9 [20.9] and - 104.5 [21.4] in patients with BMI < 25 kg/m2, ≥25 to < 30 kg/m2 and ≥ 30 kg/m2, respectively). Nintedanib reduced the rate of FVC decline versus placebo in all subgroups by BMI, with a consistent treatment effect across subgroups (interaction p = 0.31). In the placebo group, the mean rate of FVC decline was numerically greater in patients with > 5% than ≤5% weight loss over 52 weeks (- 312.7 [SE 32.2] versus - 199.5 [SE 14.4] mL/year). Nintedanib reduced the rate of FVC decline versus placebo in both subgroups by weight loss, with a greater treatment effect in patients with > 5% weight loss (interaction p = 0.0008). The adverse event profile of nintedanib was similar across subgroups.
Conclusions: In patients with IPF, lower BMI and weight loss may be associated with faster decline in FVC. Nintedanib reduces the rate of FVC decline both in patients who lose weight on treatment and those who do not.
Keywords: Interstitial lung diseases; Treatment; Vital capacity.