A multicentre retrospective observational study on Polish experience of pirfenidone therapy in patients with idiopathic pulmonary fibrosis: the PolExPIR study

BACKGROUND: Pirfenidone is an antifibrotic agent approved for the treatment of idiopathic pulmonary fibrosis (IPF). The drug is available for Polish patients with IPF since 2017. The PolExPIR study aimed to describe the real-world data (RWD) on the Polish experience of pirfenidone therapy in IPF with respect to safety and efficacy profiles. METHODS: This was a multicentre, retrospective, observational study collecting clinical data of patients with IPF receiving pirfenidone from January 2017 to September 2019 across 10 specialized pulmonary centres in Poland. Data collection included baseline characteristics, pulmonary function tests (PFTs) results and six-minute walk test (6MWT). Longitudinal data on PFTs, 6MWT, adverse drug reactions (ADRs), treatment persistence, and survival were also collected up to 24 months post-inclusion. RESULTS: A total of 307 patients receiving pirfenidone were identified for analysis. The mean age was 68.83 (8.13) years and 77% were males. The median time from the first symptoms to IPF diagnosis was 15.5 (9.75–30) months and from diagnosis to start of pirfenidone treatment was 6 (2–23) months. Patients were followed on treatment for a median of 17 (12–22.75) months. Seventy-four patients (24.1%) required dose adjustments and 35 (11.4%) were chronically treated with different than the full recommended dose. A total of 141 patients (45.92%) discontinued therapy due to different reasons including ADRs (16.61%), death (8.79%), disease progression (6.51%), patient’s own request (5.54%), neoplastic disease (3.91%) and lung transplantation (0.33%). Over up to 24 months of follow-up, the pulmonary function remained largely stable. The median annual decline in forced vital capacity (FVC) during the first year of pirfenidone therapy was −20 ml (−200–100) and during the second year was −120 ml (−340–30). Over a study period, 33 patients (10.75%) died. CONCLUSIONS: The PolExPIR study is a source of longitudinal RWD on pirfenidone therapy in the Polish cohort of patients with IPF supporting its long-term acceptable safety and efficacy profiles and reinforce findings from the previous randomised clinical trials and observational studies.