Real-World Study Analysing Progression and Survival of Patients with Idiopathic Pulmonary Fibrosis with Preserved Lung Function on Antifibrotic Treatment

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and irreversible lung disease. Licensed treatment options for IPF are pirfenidone and nintedanib. The aim of this study was to assess the impact of antifibrotic therapy in patients with IPF with preserved lung function based upon a forced vital capacity (FVC) above 80%. METHOD: This is a retrospective single-centre cohort study, performed as part of a service evaluation, between January 2007 and September 2018. Patient demographic, treatment and lung function profiles were collected using electronic patient records. A linear mixed model and Kaplan–Meier estimator were utilised to assess changes in FVC and survival over 36 months. RESULTS: A total of 161 patients were included in this study. Mean age was 72 ± 4. Twenty-four (14.9%) received pirfenidone, 86 (53.4%) received nintedanib and 18 (11.2%) received both antifibrotics provided by a compassionate use program (CUP), as the National Institute of Heath and Clinical excellence (NICE) criteria for antifibrotics in the UK is restricted to an FVC 50–80%. Thirty-three (20.5%) patients did not receive treatment. Patients without antifibrotic therapy had a statistically higher baseline FVC compared to other groups: 3.55 l (100%) vs 2.85 l (89.7%) pirfenidone (p = 0.012), vs 2.99 l (93.5%) nintedanib (p = 0.04) and 3.10 l (92.7%) (p = 0.07) for both antifibrotics. FVC decline over 1 year was similar in groups receiving pirfenidone, nintedanib or no treatment [3.72% (158.1 ml) untreated vs 2.77% (139 ml) pirfenidone vs 2.96% (131 ml) nintedanib]; however, it was significantly greater in patients who received both antifibrotics [6.36% (233 ml), p = 0.01]. Use of antifibrotics was associated with a higher median survival post diagnosis; 3.5, 3 and 3.75 years respectively in pirfenidone, nintedanib and both antifibrotic cohorts, compared to the untreated cohort (2.5 years). CONCLUSION: One in five untreated patients with an average FVC of 100% die within a median of 2.5 years. Antifibrotic therapy was associated with a higher median survival of 3–3.75 years despite treatment groups having lower baseline lung function.