Long-term survival benefit found in inhaled treprostinil treatment for pulmonary hypertension associated with IILD

A post-hoc analysis of the INCREASE trial and its open-label extension (OLE) suggests a significant long-term survival benefit associated with inhaled treprostinil treatment in patients with pulmonary hypertension associated with interstitial lung disease (PH-ILD), according to a study.

The study aimed to evaluate the extended impact of inhaled treprostinil on patient survival beyond the initial 16-week randomized trial period. Two distinct modeling techniques were employed – the inverse probability of censoring weighting (IPCW) and the rank-preserving structural failure time (RPSFT) models. Both methods enabled the construction of a pseudo-placebo group, facilitating a comprehensive assessment of long-term survival outcomes for patients with PH-ILD receiving inhaled treprostinil.

During the initial INCREASE trial, 10 deaths occurred in the inhaled treprostinil arm and 12 in the placebo arm over the 16-week period. In the subsequent open-label extension, where all patients received inhaled treprostinil, 29 deaths were recorded in the prior inhaled treprostinil group and 33 in the prior placebo group.

Conventional analysis yielded a hazard ratio for death of 0.71. However, both the IPCW and RPSFT models demonstrated significant reductions in death associated with inhaled treprostinil treatment, with hazard ratios of 0.62 and 0.26, respectively.

The findings suggest a consistent and robust long-term survival benefit associated with inhaled treprostinil treatment in patients with PH-ILD. Notably, the use of two independent modeling techniques, commonly employed in oncology literature, strengthens the credibility of the results.

Reference
Nathan SD, Johri S, Joly JM, et al. Survival analysis from the INCREASE study in PH-ILD: evaluating the impact of treatment crossover on overall mortality. Thorax. 2023;thorax-2023-220821. doi: 10.1136/thorax-2023-220821. Epub ahead of print. PMID: 37979971.