Clinical Experience of the Long-term Use of Pirfenidone for Idiopathic Pulmonary Fibrosis

Abstract

Objective: Long-term effects of pirfenidone have been poorly understood to date. This study investigated the clinical efficacy and safety of long-term pirfenidone use for idiopathic pulmonary fibrosis (IPF) in clinical practice.

Methods: This survey study was a retrospective observational study. A survey was used to collect clinical information on IPF cases that were treated with pirfenidone. This survey sheet came from physicians belonging to the Diffuse Lung Diseases Research Group.

Results: 502 patients at 22 institutes received pirfeidone treatment. Of the 502 cases, pirfenidone treatment was terminated in under one year in 186 cases (37.1%); adverse effect was the most frequent reason for termination. The pirfenidone treatment lasted for two years or longer in 111 cases (22.1%). The mean change in the forced vital capacity (FVC) was -30±224 (SD) mL in the first year of treatment, -158±258 mL in the second year, and -201±367 mL in the third year. FVC improved by 10% or more in the first year in 10 (14.7%) of 68 cases, and showed a change of ±10% in 47 (69.1%) cases. It showed a change of ±10% in the second and third years in 61.7% and 62.5% of the patients, respectively.

Conclusion: The FVC improved in only a small percentage of patients who received pirfenidone treatment for a long period of time. However, a decrease in the FVC was prevented for three years in over half of the cases.