Late Breaking Abstract - Determinants of Non-Persistence to Antifibrotic Therapy in Real-World Clinical Practice in the French population

<bold>Introduction:</bold> Antifibrotics (AF) significantly enhance patient survival, yet low treatment persistence rates may lead to unsatisfactory outcomes. <bold>Aims and Objectives:</bold> This nationwide study aimed to assess AF treatment persistence and identify factors associated with non-persistence in real-life settings. <bold>Methods:</bold> Using the SNDS healthcare database, we identified all patients who initiated AF treatment between 2019 and 2021 in France, and calculated their persistence rate until lung transplantation, death, or end of study (December 31, 2022). A Fine and Gray regression model was used to account for the competing risks of lung transplantation and death. <bold>Results:</bold> 4,935 patients were included, including 69.7% diagnosed with idiopathic pulmonary fibrosis, 5.0% with systemic sclerosis, and 25.3% with other diagnoses. Patients were treated with nintedanib (n=3,351, 67.9%) or pirfenidone (n=1,584, 32.1%). At 12 months, persistence rates were 68.1% for nintedanib and 61.3% for pirfenidone. A persistence decrease of nearly 15% was observed between months 6 and 12, followed by a slower decline, reaching 53.1% (nintedanib) and 50.7% (pirfenidone) at month 30. Persistence was significantly lower (p<0.001) in patients with oxygen therapy during follow-up (sHR=1.22), those with <2 pulmonary function tests (sHR=3.25), or followed outside expert centers (sHR=1.61). <bold>Conclusion:</bold> This real-life study, encompassing 99% of the French population, highlighted that one-third of AF-treated patients discontinued therapy within the first year. Persistence was influenced by clinical status and care pathways, underscoring the need for longitudinal follow-up to improve long-term persistence.