Exposure-safety analyses of nintedanib in patients with chronic fibrosing interstitial lung disease

Background: Nintedanib reduces the rate of decline in forced vital capacity in patients with idiopathic pulmonary fibrosis (IPF), other chronic fibrosing interstitial lung diseases (ILDs) with a progressive phenotype and systemic sclerosis-associated ILD (SSc-ILD). The recommended dose of nintedanib is 150 mg twice daily (BID).

Methods: Data from Phase II and III trials in IPF and Phase III trials in SSc-ILD and progressive fibrosing ILDs other than IPF were analyzed to investigate the relationship between nintedanib plasma concentrations (exposure) and safety (liver enzyme elevations [defined as transaminase elevations equal or greater than 3 times the upper limit of normal] and diarrhea).

Results: Using data from 1403 subjects with IPF treated with 50-150 mg nintedanib BID, a parametric time-to-first-event model for liver enzyme elevations was established. Besides exposure, gender was a significant covariate, with a three-fourfold higher exposure-adjusted risk in females than males. Subsequent analysis of combined data from IPF, SSc-ILD (n = 576) and progressive fibrosing ILD (n = 663) studies suggested a consistent exposure-liver enzyme elevation relationship across studies. No exposure-diarrhea relationship was found using data from the various fibrosing ILDs, but diarrhea risk was dependent on dose administered.

Conclusions: The positive correlation between exposure and risk of liver enzyme elevations was consistent across nintedanib studies in IPF, SSc-ILD and progressing fibrosing ILDs other than IPF. The effect size does not warrant a priori dose adjustment in patients with altered plasma exposure (excluding hepatic impairment patients, where there are specific labelling recommendations). For diarrhea, dose administered was a better predictor than exposure.