Background and Importance Pirfenidone and nintedanib have been proven survival benefits and been currently approved for idiopathic pulmonary fibrosis (IPF). However, real-world comparison of effectiveness between two antifibrotics remains limited in Asia.

Aim and Objectives Our study was aimed to assess: (1) factors associated with the choice of pirfenidone versus nintedanib; (2) dose modification during treatment; (3) overall survival (OS).

Material and Methods We conducted a retrospective cohort study by using the largest multi-institutional electronic medical records in Taiwan. We included IPF patients newly receiving pirfenidone or nintedanib during 2018–2020. We followed up included patients to death, loss of follow-up or December 2022. The clinical factors included age, sex, lung function, biochemical data, comorbidities and co-medications. Multiple logistic regression analysis was used to assess factors associated with drug choice. Dose modification was assessed every 3 months by using dose intensity in follow-up period based on as-treated analysis. In OS analysis, we applied probability of treatment weighting (IPTW) and Cox regression model to enhance the comparability of study subjects and estimate hazard ratio (HR) between two treatment groups, respectively.

Results A total of 86 patients receiving pirfenidone and 142 patients receiving nintedanib. Mean age and Forced vital capacity (FVC) were 70.7 11.3 years and 68.8 17.4%, respectively. The use of nintedanib was positively associated with the patients with chronic kidney disease (CKD) (odds ratio: 2.1, 95% CI: 1.06 – 4.18). Dose reduction rate was similar between two groups (59.3% vs. 65.4%, P = 0.34). After a median of 25.5 months follow-up, nintedanib users were associated with worsen OS than pirfenidone users (adjusted HR: 2.07, 95% CI: 1.24 – 3.45).

Conclusion and Relevance Our study showed CKD patients were likely prescribed nintedanib. Pirfenidone users had association of better all-cause mortality than nintedanib users. Further studies are suggested to confirm our findings.

Conflict of Interest No conflict of interest.