Dry Powder Treprostinil Tolerated Among Patients with PH-ILD, with Nicholas Kolaitis, MD

Dry powder formulation of inhaled prostacyclin analog treprostinil (LIQ861; Yutrepia) showed consistent safety and tolerability in patients with pulmonary hypertension associated with interstitial lung disease (PH-ILD), while also providing marked improvements to 6-minute walk distances (6MWD), according to 16-week interim data from the ASCENT trial.1

The interim findings from the ongoing 52-week trial, presented in late-breaking sessions at the American College of Chest Physicians (CHEST) 2025 Annual Meeting in Chicago, IL, this week, provide evidence toward a new method of treatment for patients with PH-ILD.

Investigators led by Nicholas Kolaitis, MD, MS, associate professor of medicine at the University of California – San Francisco, reported 16-week outcome data of 54 patients with PH-ILD enrolled in ASCENT. Mean patient age was 68.5 years old; 48.1% were male; ILD etiology was predominately interstitial pneumonias (48.1%) and autoimmune ILDs (35.2%).

Median doses of the titration regimen were 132.5 mcg and 159 mcg at weeks 8 and 16, respectively. Investigators observed a median improvement of 31.5 meters in 6MWD at 16 weeks — with 32% of patients improving their baseline distance by ≥50 meters. Mean patient Dyspnea-12 and EmPHasis-10 scores — questionnaires for breathlessness and impact of PH on quality of life, respectively — additionally improved from baseline.

Kolaitis and colleagues observed treatment-related adverse events in 70.4% of patients, the most common being cough (n = 26 [48.1%]) and headache (n = 10 [18.5%]). Ten patients (18.5%) discontinued the study on or before their week 16 visit — though none discontinued due to treatment-related adverse events.

In an interview with HCPLive at CHEST 2025, Kolaitis discussed the novel delivery of dry powder inhaled treprostinil, which is designed for a deeper lung delivery through smaller particle size than prior iterations of the agent.

The US Food and Drug Administration (FDA) approved treprostinil inhalation powder formula for both pulmonary arterial hypertension (PAH) and PH-ILD in May of this year. The approval was based on the phase 3 INSPIRE trial, which showed patients maintained or improved disease status through 1 year of treatment.2

“If we were to find pulmonary hypertension in the context of ILD, there's upside in the sense that this is the only therapy that we have that actually…make them better in the ILD space,” Kolaitis said. “All the other medications in the ILD space are intended to slow progression of disease, which doesn't actually make patients feel better — which is problematic, because you’re telling somebody, ‘Let's go into therapy and just prevent you from getting worse.’”

Though cough was a highly prevalent adverse event — a common trend with dry powder or nebulized formulas — Kolaitis found relief that a significant majority of patients only reported mild cough, and that it did not increase in frequency over the 16 weeks.

“So it seems like even though patients do have cough, [it] was not worse after starting this new formulation, which has allowed us to get to higher doses faster, and to higher doses in general,” he said.” And I think that the big implication here is that it's easier to tolerate, it's easy to use. You can get to higher doses faster, so you can impact change a lot quicker in your patients, which potentially could lead to better outcomes down the line.”

References

1. Kolaitis N, Saggar R, Ravichandran A, Muralidhar A, et al. Safety and Exploratory Efficacy Data of LIQ861 Dry Powder Inhaled Treprostinil in PH-ILD Patients: Ascent to Week 16. Poster presented at: CHEST Annual Meeting 2025. Chicago, IL. October 19 – 22, 2025.
2. Iapoce C. FDA Approves Treprostinil Inhalation Powder for PAH, PH-ILD. HCPLive. Published online May 23, 2025. https://www.hcplive.com/view/fda-approves-treprostinil-inhalation-powder-for-pah-ph-ild