Timing of antifibrotic therapy and prognosis in idiopathic pulmonary fibrosis: real-world evidence from the French Colibri-ILD SNDS database

Abstract

According to the French 2022 National guideline, antifibrotic therapy should be initiated as soon as a diagnosis of idiopathic pulmonary fibrosis (IPF) is made, taking into account the individual assessment of the expected benefit and risks of treatment. However, in practice, treatment may be deferred for various reasons. We aimed to assess the association between deferred antifibrotic initiation and survival, disease worsening, and healthcare resource utilization in incident IPF patients. We conducted a retrospective analysis of the French National Health Data System (SNDS) linked to the Colibri-ILD registry between 2016 and 2023. Clinical outcomes were compared between patients who initiated antifibrotic therapy promptly (up to 181 days after IPF diagnosis) and those initiating treatment between 182 and 365 days after IPF diagnosis (‘deferred initiation’). Stabilized Inverse Probability of Treatment Weighting (SIPTW) was used to minimize between-groups differences in demographic and clinical characteristics at diagnosis. The primary outcome was overall survival. Secondary outcomes included healthcare resource utilization and several time‑to‑event outcomes: initiation of supplemental oxygen therapy, respiratory‑related hospitalization, and disease worsening, defined as a composite of death, respiratory‑related hospitalization (including IPF exacerbation), or lung transplantation. A total of 207 patients (mean age 72.7 years; 23.2% female) were included; antifibrotic therapy was initiated promptly in 168 patients (81.0%) and was deferred in 39 patients (19%). Overall survival, time to initiation of supplemental oxygen therapy, and healthcare resource utilization did not differ between groups. However, deferred initiation was associated with an increased risk of disease worsening (HR 1.57; 95% CI 1.05–2.35; p = 0.03) and an increased risk of respiratory‑related hospitalizations (HR:1.81, 95% CI 1.18–2.77; p = 0.01). In this real-world study, most patients initiated antifibrotic therapy within six months of IPF diagnosis. Deferred initiation of antifibrotic therapy was associated with worse clinical outcomes, particularly a higher risk of disease worsening. These findings support prompt initiation of antifibrotic treatment in patients with IPF, in line with current guidelines.