Real‐World Comparison of Patients With PH‐ILD Initiating Inhaled Treprostinil Versus Patients Who Remain Untreated

Pulmonary hypertension due to interstitial lung disease (PH-ILD) is associated with high morbidity and mortality. Real-world patients initiating inhaled treprostinil are not well-characterized. This retrospective cohort study aimed to evaluate healthcare resource utilization in patients with PH-ILD who initiated treatment with inhaled treprostinil vs patients who remained untreated. Adult patients diagnosed with PH-ILD were indexed on initiation of inhaled treprostinil and patients who remained untreated were indexed on first observed PH diagnosis (31 March 2021-30 September 2024). Patients were excluded if they were ever treated with any pulmonary arterial hypertension therapy. Inhaled treprostinil patients were matched to up to four untreated patients. All-cause per-patient per-month (PPPM) hospitalizations and ICU-related hospitalizations were the primary outcomes of interest. 294 patients treated with inhaled treprostinil and 736 untreated patients were identified. Mean all-cause PPPM hospitalizations remained unchanged in the pre-index vs post-index periods in the inhaled treprostinil cohort (0.11 vs 0.12; <i>p</i> = 0.42) but significantly increased in untreated patients (0.12 vs 0.23; <i>p</i> < 0.01). ICU utilization also remained unchanged in the pre-index vs post-index periods for the inhaled treprostinil cohort (0.06 vs 0.07; <i>p</i> = 0.11) compared to the untreated cohort (0.06 vs 0.13; <i>p</i> < 0.01). Untreated patients had significantly higher post-index PPPM hospitalizations (<i>p</i> < 0.01) and ICU utilization (<i>p</i> < 0.01) compared to inhaled treprostinil patients. Patients who initiated inhaled treprostinil had a 30% decreased risk of hospitalization compared to untreated patients (relative risk: 0.70; 95% CI: 0.59-0.83; <i>p</i> < 0.01). Among real-world patients with PH-ILD, treatment with inhaled treprostinil is associated with fewer all-cause hospitalizations and ICU-related hospitalizations compared to untreated patients with PH-ILD.