ILD O-009 : Effect of Low Dose Pirfenidone on Survival and Lung Function Decline in Patients with Idiopathic Pulmonary Fibrosis (IPF): Results from a Real-life Study

Purpose IPF is a specific form of chronic and progressive fibrosing interstitial pneumonia of unknown cause. Pirfenidone has been proven to be effective and safe in the treatment of IPF. However, the dose of pirfenidone used in Korea is usually lower than the dose established in global clinical trial. The aim of this study was to evaluate the efficacy of relatively lower dose of pirfenidone on disease progression and survival of IPF patients in real-world. Methods This is a retrospective observational study based on IPF cohort in which IPF patients were enrolled at the time of diagnosis at a single center from 2008 to 2018. The clinical and laboratory data of these patients were collected prospectively using an IPF-specified protocol. We compared the clinical characteristics, overall survival and pulmonary function decline of the patients treated with variable dose of pirfenidone with patients not treated with pirfenidone. Results Of the total 295 patients with IPF, 100 (33.9%) received pirfenidone and 195 (66.1%) were not prescribed antifibrotic agents. Of the 100 patients who received pirfenidone, 24% (24/100), 50% (50/100), and 26% (26/100) were given 600mg, 1200mg, and 1800mg of pirfenidone, respectively. In unadjusted analysis, the survival of the patient group using pirfenidone was significantly better than that of the group not using pirfenidone (HR: 0.69, 95% CI: 0.48-0.99, p = 0.04). After adjusted for age, gender, BMI and GAP score, the survival remained higher in the patients using pirfenidone (HR: 0.56, 95% CI: 0.37-0.85, P = 0.006). In the analysis of pulmonary function, the decline in FVC, FEV1 and DLCO was significantly lower (p = 0.0068, p = 0.0007 and p = 0.0034, respectively) in the group using pirfenidone compared to the group not using it. Conclusion Low dose pirfenidone provided beneficial effects on survival and pulmonary function decline in real-life practice.