Introduction: The INBUILD trial found that patients with fibrosing interstitial lung diseases treated Nintedanib demonstrated a slower rate of progression than with placebo (Flaherty KR, et al. N Engl J Med. 2019;381:1718-1727). This study aims to analyse key clinical and survivability characteristics of a PFILD cohort treated with Nintedanib at a specialist centre in the UK.

Methods: Retrospective data was collected from 138 patients from our centre over a 3-year period (November 2019-2022) from a Named Individual Patient Supply and a service evaluation. All 138 patients were diagnosed with PFILD after MDT consensus according to criteria from the INBUILD trial. Statistical analysis was performed on variables between surviving and deceased patients.

Results: Of the 138 PFILD patients, 31 (22%) had passed away by December 2022. 98 PFILD patients (71%) started Nintedanib before December 2022. There was no statistically significant difference when considering age at diagnosis, sex, underlying fibrotic lung disease nor concomitant immunosuppression. Severity of disease progression (?10% decline in FVC at diagnosis) was found to have a statistically significant impact on survival; 35.5% of deceased patients meeting this criterion. Lower baseline FVC (notably <70%) also demonstrated a statistically significant difference. Our data showed a trend towards an indeterminate usual interstitial pneumonia (UIP) pattern as predictor of mortality; however, further studies are necessary to confirm this.

Conclusion: From our PFILD cohort lower baseline FVC and an indeterminate UIP pattern on CT-scan were all associated with an increased mortality risk.