Safety, effectiveness, and usefulness of higher-dose tablets of generic pirfenidone in patients with IPF: a nationwide observational study in South Korea

Abstract

Background Pirfenidone is an antifibrotic medication approved for idiopathic pulmonary fibrosis (IPF). Fybro (R), a generic version of pirfenidone developed in South Korea, gained approval and is available in 200 mg and in higher-dose formulations of 400 and 600 mg. This real-world prospective cohort study investigated the safety and effectiveness of Fybro (R).Methods A nationwide observational study was conducted in patients with IPF. Patients were followed up for 6 months, with a subset of patients being followed up for 12 months. Data on lung function and adverse events were collected. Patient adherence to fewer-pill (400 and/or 600 mg tablets) and multiple-pill (200 mg tablets) regimens were compared.Results Of the 359 enrolled patients, 352 received pirfenidone (Fybro (R)) at least once and were included in the analysis. The mean age was 69.0 years and 82.4% of patients were male. The median treatment duration was 186.0 days. A total of 253 patients (71.9%) experienced adverse events, with decreased appetite being the most common (16.5%). The adjusted decline rates in lung function were -1.5% and -2.2% predicted per year for forced vital capacity and diffusing capacity, respectively. No significant differences were observed based on the pirfenidone dose. For a daily intake of 1,200 or 1800 mg of pirfenidone, a significantly longer duration of drug administration was observed with the fewer-pill regimen than with multiple-pill regimen.Conclusion The safety and effectiveness of Fybro (R) observed in this real-world cohort study are consistent with previous studies. Using higher-strength tablets to reduce pill burden may improve medication adherence.