(P-392) Characteristics of Patients with Idiopathic Pulmonary Fibrosis (IPF) Initiating Nintedanib or Pirfenidone Treatment Compared with Untreated Patients in the US

Background: Nintedanib and pirfenidone reduced the rate of decline in forced vital capacity in IPF clinical trials and have been available in the US since 2014.

Objectives: To compare the characteristics of IPF patients initiating nintedanib or pirfenidone treatment with those not receiving antifibrotic treatment in the real world to better understand prescribing patterns in the US.

Methods: Patients (≥40 years) with ≥1 IPF diagnosis in Centricity Electronic Medical Record database (primary and ambulatory care data) from 01/10/2013 to 31/10/2018 were included. Three cohorts were created: patients with ≥1 prescription for nintedanib (new users), ≥1 prescription for pirfenidone (new users), and no antifibrotic treatment. Index date was treatment initiation. Index date for the untreated cohort was assigned based on the distribution of time from the earliest IPF diagnosis to the first prescription in the treated cohorts. Patient characteristics and treatments during the 12-month pre-index period were described using absolute and relative frequencies for categorical variables and means and standard deviation for continuous variables. Differences were assessed using absolute standardised difference (ASD). Multivariate logistic regression analyses assessed the adjusted odds ratio (OR) including the 95% confidence interval (CI) of receiving an antifibrotic.

Results: IPF patients treated with nintedanib (n=347) or pirfenidone (n=423) and those untreated (n=12494) were identified. Nintedanib- and pirfenidone-treated patients were older (71.6 and 72.1 vs 70.9 years, ASD=-0.08 and 0.02, respectively), had significantly higher body mass index (29.5 and 30.1 vs 28.6 kg/m2, ASD=0.2 and 0.3, respectively) and lower Charlson Comorbidity Index (0.7 and 0.8 vs 1.1, ASD=-0.3 and -0.2, respectively) vs untreated patients. Obesity (OR 1.8 [1.5–2.3]), gastroesophageal reflux disease (OR 1.6 [1.3–2.0]), spirometry (OR 1.5 [1.3–1.8]), below-normal oxygen saturation (OR 1.6 [1.3–1.9]) and prednisone use (OR 1.6 [1.3–1.8]) increased the odds of receiving an antifibrotic, while heart failure (OR 0.4 [0.3–0.7]), hypertension (OR 0.7 [0.5–0.8]) and renal or hepatic impairment (OR 0.5 [0.3–0.7]) decreased the odds.

Conclusions: Antifibrotic-treated IPF patients were more overweight but had fewer comorbidities than untreated patients in this study. IPF patients with chronic comorbidities such as cardiovascular disease were less likely to receive treatment. Treated patients are likely underrepresented in this primary care database as they are often managed in specialty care settings.