D22-21 Real-world Comparison of Antifibrotic-Treated and Untreated Patients With Idiopathic Pulmonary Fibrosis in a Commercial and Medicare Advantage Population

Abstract Rationale Contemporary real-world data on antifibrotic therapy in idiopathic pulmonary fibrosis (IPF) are needed to better understand differences in characteristics and outcomes between treated and untreated patients. Methods A retrospective cohort study was conducted using the Optum’s de-identified Clinformatics® Data Mart Database. Patients with IPF initiating antifibrotic therapy between 01/01/17 through 09/30/24, comprised the treated group, indexed on the first treatment date. Untreated patients were indexed on their first IPF diagnosis date plus a randomly selected time interval, drawn from the distribution of observed diagnosis-to-treatment intervals in the treated cohort. Eligible patients were aged ≥18 years, had ≥1 inpatient or ≥ 2 outpatient claims for IPF (≥30 days apart) before index, ≥6 months of continuous enrollment pre-index, and no prior antifibrotic use or lung transplant. Propensity score matching (1:2, caliper=0.2) was applied to balance baseline characteristics and comorbidities. Patients were censored at lung transplant, disenrollment, or end of data availability. Adherence was measured using the proportion of days covered (PDC), and persistence was defined using a 45-day gap. Per-patient-per-month (PPPM) healthcare resource utilization and mortality were assessed. Results A total of 2,026 treated patients were identified and matched to 3,570 untreated patients. The mean (SD) age was 74.7 (8.2) vs 75.2 (8.3) years (SMD = 0.05), and 39.5% vs 42.0% were female (SMD = 0.05). The mean (SD) Quan-Charlson comorbidity index was 2.3 (2.1) vs 2.5 (2.1) (SMD=0.07), respectively. The mean (SD) follow-up duration was 39.6 (0.9) vs 41.9 (0.8) months. Post-index mean (SD) all-cause per-patient-per-month (PPPM) inpatient hospitalizations were 0.10 (0.27) vs 0.11 (0.30) (p = 0.16), and ICU utilization was 0.05 (0.11) vs 0.08 (0.13) (p = 0.26) for treated vs untreated cohorts, respectively. The time to death for 25% of patients was 14.0 months for treated and 9.1 months for untreated, while median survival was 32.1 vs 33.7 months after treatment initiation. Among treated patients, 25% discontinued within 2.2 months and 50% discontinued antifibrotic therapy within 6.8 months. The mean (SD) proportion of days covered (PDC) was 0.60 (0.38); 44.2% achieved PDC ≥ 0.8 and 57.3% achieved PDC ≥ 0.5. Conclusions Treated and untreated IPF patients had comparable healthcare utilization and hospitalization rates, with high mortality observed in both groups. Treated patients also had high rates of discontinuation to antifibrotics shortly after initiation, underscoring the need for more tolerable and efficacious antifibrotic therapies for patients living with IPF. This abstract is funded by: United Therapeutics Corporation