Effect of pirfenidone on lung function decline and survival: 5-yr experience from a real-life IPF cohort from the Czech EMPIRE registry

INTRODUCTION: Pirfenidone, an antifibrotic drug, slows-down the disease progression in idiopathic pulmonary fibrosis (IPF) over 12 months, however limited data on the decline of lung function and overall survival (OS) in real-world cohorts on longer follow-up exists. PATIENTS/METHODS: Of the enrolled Czech IPF patients (n = 841) from an EMPIRE registry, 383 (45.5%) received pirfenidone, 218 (25.9%) no-antifibrotic treatment and 240 (28.5%) were excluded (missing data, nintedanib treatment). The 2- and 5-yrs OS and forced vital capacity (FVC) and diffusing lung capacity for carbon monoxide (DL(CO)) were investigated at treatment initiation and 6, 12, 18 and 24 months’ follow-up. RESULTS: During a 2-yr follow-up, less than a quarter of the patients progressed on pirfenidone as assessed by the decline of ≥10% FVC (17.0%) and ≥ 15% DL(CO) (14.3%). On pirfenidone, the DL(CO) (≥10%) declines at 6, 12, 18 and 24 months’ and DL(CO) (≥15%) declines at 6, 18 and 24 months’ follow-up were associated with increased mortality. The DL(CO) decline showed higher predictive value for mortality than FVC decline. In patients with no-antifibrotics, FVC and DL(CO) declines were not predictive for mortality. Pirfenidone increased 5-yrs OS over no-antifibrotic treatment (55.9% vs 31.5% alive, P = 0.002). CONCLUSION: Our study observed the 2-yrs sustained effect of pirfenidone on the decline of lung function and survival in the real-world patient’s IPF cohort. DL(CO) decline of ≥10% shows a potential as a mortality predictor in IPF patients on pirfenidone, and should be routinely evaluated during follow-up examinations.