Introduction: Tyvaso DPI (treprostinil) inhalation powder is FDA-approved for patients with pulmonary arterial hypertension and pulmonary hypertension due to interstitial lung disease (PH-ILD). Real-world evidence on the use of Tyvaso DPI in patients with PH-ILD and clinical outcomes are limited.

Objectives: To observe the change in six-minute walk distance (6MWD) from baseline up to 12-months in patients newly initiating Tyvaso DPI.

Materials and Methods: This retrospective cohort study utilized de-identified US electronic health record data sourced by OMNY Health Real-World Data Platform. Patients receiving Tyvaso DPI from 25-MAY-22 through 30-JUN-25 were identified and indexed at treatment initiation. Patients were required to be ≥18 years old at index and have a diagnosis of PH-ILD on or prior to initiation. Patients with use of another prostacyclin prior to index, receipt of lung transplant at anytime in their record or missing 6MWD before or after initiation were excluded from the analysis. Baseline 6MWD captured the closest recorded value prior to the initiation date. Post-index 6MWD captured the farthest value within 12 months after initiation date. Descriptive statistics were utilized and change in 6MWD from baseline was compared using paired t-tests.

Results: 52 patients with PH-ILD newly initiating Tyvaso DPI were included for analysis. Patients were predominantly White (28, 54%) females (36, 69%) with a mean(SD) age of 68.7 (11.2) years. 32(62%) patients were using supplemental oxygen, 15(29%) patients were receiving an antifibrotic while 14(27%) were on a phosphodiesterase-5 inhibitor. The mean(SD) baseline 6MWD was 251.0(107.7) meters recorded 43.0(44.8) days prior to initiation of Tyvaso DPI. Over a mean(SD) follow-up period of 201.4(101.5) days, 6MWD increased by 31.2(72.6) meters, p=0.003.

Conclusions: This real-world analysis of US electronic health records of patients with PH-ILD observed an association between initiating Tyvaso DPI and increased 6MWD.