Inhaled Treprostinil and FVC Change in Patients With Interstitial Lung Disease and Associated Pulmonary Hypertension

Background: INCREASE was a multicenter, randomized, double-blind, placebo-controlled, 16-week study that evaluated the safety and efficacy of inhaled treprostinil in patients with interstitial lung disease and associated pulmonary hypertension (PH-ILD). The study met its primary endpoint of change in peak 6-minute walk distance at Week 16. Methods: Pulmonary function testing and exacerbations of underlying lung disease were conducted as safety assessments. This current analysis assessed the effects of inhaled treprostinil on the forced vital capacity (FVC). Findings: 326 patients were randomized to inhaled treprostinil or placebo. Inhaled treprostinil was associated with placebo-corrected improvements in the FVC of 28·5 mL (95% CI -30·8-87.7, p=0·345) and 44·4 mL (95% CI -25·3-114·1, p=0·211) at Weeks 8 and 16, respectively. The associated percent predicted FVC improvements at Weeks 8 and 16 were 1·79% (95% CI 0·37-3·21, p=0·014) and 1·80% (95% CI 0·20-3·39, p=0·028), respectively.  Patients with idiopathic interstitial pneumonia (IIP) demonstrated FVC improvements of 46·5 mL (n=129, 95% CI -32·55-125·5, p=0·247) and 108·2 mL (n=115, 95% CI 15·3-201·1, p=0·023) at Weeks 8 and 16, respectively. Patients with idiopathic pulmonary fibrosis (IPF) demonstrated FVC improvements of 84·5 mL (n=78, 95% CI -20·4-189·5, p=0·113) and 168·5 mL (n=70, 95% CI 40·1-297·0, p=0·011) at Weeks 8 and 16, respectively. Interpretation: In patients with PH-ILD, inhaled treprostinil resulted in improvements in FVC compared to placebo. This difference was most evident in patients with IIP and in particular, IPF. Inhaled treprostinil appears to be a promising therapy for IPF that warrants further prospective clinical study. Trial Registration: The INCREASE study (NCT02630316) is registered with ClinicalTrials.gov. Funding Statement: The INCREASE study was funded by United Therapeutics Corporation. Declaration of Interests: SDN has received research funding and consulting fees from United Therapeutics. He has received consulting fees from Boehringer-Ingelheim, Roche-Genentech and Galapagos. He is also on the speakers bureau for Boehringer-Ingelheim and Roche-Genentech. AW reports grants from United Therapeutics Corporation, during the conduct of the study. SR reports grants from United Therapeutics Corporation, during the conduct of the study; grants and personal fees from United Therapeutics, grants and personal fees from Janssen Pharmaceuticals, personal fees from Altavant Sciences, personal fees from Liquidia Technologies, Inc., personal fees from Insmed, Inc., personal fees from Bayer Pharmaceuticals, outside the submitted work. AC reports grants from United Therapeutics Corporation, during the conduct of the study. SJ reports grants from United Therapeutics Corporation, during the conduct of the study; grants and personal fees from Bayer Pharmaceuticals, grants from Bellerophon Therapeutics, grants and personal fees from Janssen Research and Development, outside the submitted work. HD reports grants from United Therapeutics Corporation during the conduct of the study; grants and personal fees from Actelion Pharmaceuticals, outside the submitted work. DZ reports grants from United Therapeutics Corporation, during the conduct of the study. SS reports grants from United Therapeutics Corporation, during the conduct of the study; personal fees and non-financial support from Bayer Pharmaceuticals, personal fees and non-financial support from United Therapeutics, personal fees and non-financial support from Actelion Pharmaceuticals, personal fees from Liquidia, personal fees from Altavant Sciences, from GSK, grants from ACCP CHEST ILD Research Grant, personal fees from Boehringer Ingelheim, outside the submitted work. CK reports grants from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics, personal fees from Actelion, personal fees from Boehringer Ingelheim Pharmaceuticals, personal fees from Genentech, outside the submitted work. LMG reports grants and personal fees from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics Corporation, personal fees from Janssen and Janssen Pharmaceuticals, personal fees from Bayer Pharmaceuticals, outside the submitted work. PS reports personal fees from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics Corporation, outside the submitted work. ES reports personal fees from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics Corporation, outside the submitted work. LDE reports personal fees from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics Corporation, outside the submitted work. AN reports personal fees from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics Corporation, outside the submitted work. VFT reports grants from United Therapeutics Corporation, during the conduct of the study; personal fees from United Therapeutics, outside the submitted work. Ethics Approval Statement: The study protocol was approved by the institutional review board at each participating site. The study was monitored by an independent data and safety monitoring committee and was conducted in accordance with the principles of Good Clinical Practice.