Comparative outcomes in patients receiving pirfenidone or nintedanib for idiopathic pulmonary fibrosis

Background Real-world data regarding outcomes of idiopathic pulmonary fibrosis (IPF) are scarce, outside of registries. In France, pirfenidone and nintedanib are only reimbursed for documented IPF, with similar reimbursement criteria with respect to disease characteristics, prescription through a dedicated form, and IPF diagnosis established in multidisciplinary discussion. Research question The data of the comprehensive French National Health System were used to evaluate outcomes in patients newly treated with pirfenidone or nintedanib in 2015-2016. Study design and methods Patients aged < 50 years or who had pulmonary fibrosis secondary to an identified cause were excluded. All-cause mortality, acute respiratory-related hospitalisations and treatment discontinuations up to 31 December 2017 were compared using a Cox proportional hazards model adjusted for age, sex, year of treatment initiation, time to treatment initiation and proxies of disease severity identified during a pre-treatment period. Results During the study period, a treatment with pirfenidone or nintedanib was newly initiated in 804 and 509 patients, respectively. No difference was found between groups for age, sex, time to treatment initiation, Charlson comorbidity score, and number of hospitalisations or medical contacts prior to treatment initiation. As compared to pirfenidone, nintedanib was associated with a greater risk of all-cause mortality (hazard ratio [HR], 1.8; 95% confidence interval [CI] 1.3-2.6), a greater risk of acute respiratory-related hospitalisations (HR 1.3; 95% CI 1.0-1.7) and a lower risk of treatment discontinuation at 12 months (HR 0.7; 95% CI 0.6-0.9). Interpretation This observational study identified potential differences in outcome under newly prescribed antifibrotic drugs, deserving further explorations.