Efficacy of lower dose pirfenidone for idiopathic pulmonary fibrosis in real practice: a retrospective cohort study
Hyeontaek Hwang, Jung‐Kyu Lee, Sun Mi Choi, Yeon Joo Lee, Young‐Jae Cho, Ho Il Yoon, Jae Ho Lee, Choon‐Taek Lee, Young Whan Kim, Jong Sun Park
Abstract
BACKGROUND/AIMS: Pirfenidone slows the progression of idiopathic pulmonary fibrosis (IPF). We investigated its efficacy and safety in terms of dose and disease severity in real-world patients with IPF. METHODS: This multicenter retrospective cohort study investigated 338 patients treated with pirfenidone between July 2012 and March 2018. Demographics, pulmonary function, mortality, and pirfenidone-related adverse events were also investigated. Efficacy was analyzed according to pirfenidone dose and disease severity using linear mixed-effects models to assess the annual decline rate of forced vital capacity (FVC) and diffusing capacity of the lungs for carbon monoxide (DLCO). RESULTS: The mean %FVCpredicted and %DLCOpredicted values were 72.6% ± 13.1% and 61.4% ± 17.9%, respectively. The mean duration of pirfenidone treatment was 16.1 ± 9.0 months. In the standard dose (1,800 mg/day) group, the mean %FVCpredicted was -6.56% (95% confidence interval [CI], -9.26 to -3.87) per year before, but -4.43% (95% CI, -5.87 to -3.00) per year after treatment with pirfenidone. In the non-standard lower dose group, the mean %FVCpredicted was -4.96% (95% CI, -6.82 to -3.09) per year before, but -1.79% (95% CI, -2.75 to -0.83) per year after treatment with pirfenidone. The FVC decline rate was significantly reduced, regardless of the Gender-Age-Physiology (GAP) stage. Adverse events and mortality were similar across dose groups; however, they were more frequent in GAP stages II-III than in the stage I group. CONCLUSION: The effect of pirfenidone on reducing disease progression of IPF persisted even with a consistently lower dose of pirfenidone.