The TETON study is a 396-patient, multicenter, randomized, double-blind, placebo-controlled phase 3 registration study to evaluate the safety and efficacy of inhaled treprostinil in subjects with idiopathic pulmonary fibrosis (IPF) over a 52-week period.
Subjects will be randomly allocated 1:1 to receive inhaled treprostinil or placebo. All subjects will initiate inhaled treprostinil or placebo at a dose of three breaths administered four times daily (QID) and will titrate to a target dosing regimen of 12 breaths QID. Study drug doses may be titrated up as tolerated, until the target dose or maximum clinically tolerated dose is achieved.
The primary endpoint of the study is the change in FVC from baseline to week 52. Secondary endpoints include: (1) time to clinical worsening; (2) time to first acute exacerbation of IPF; (3) overall survival at week 52; (4) change in percent predicted FVC from baseline to week 52; and (5) change in the King’s Brief Interstitial Lung Disease questionnaire.
Other data collected in the study will include the plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration, supplemental oxygen use, and lung diffusion capacity. Safety assessments include the development of adverse events, serious adverse events, vital signs, clinical laboratory parameters, and electrocardiogram parameters.
This program was prompted by data from the INCREASE study, which demonstrated improvements in parameters of lung function in pulmonary hypertension patients with fibrotic lung disease, including absolute FVC, and reduced exacerbations of underlying lung disease. Specifically, in the INCREASE study, treatment with inhaled treprostinil resulted in significant improvements in percent predicted FVC at Weeks 8 and 16, with subjects having underlying etiologies of IIP (Week 8: 1.95%, p=0.0373 and Week 16: 2.88%; p=0.0096) and idiopathic pulmonary fibrosis (Week 8: 2.543%; p=0.0380 and Week 16: 3.504%; p=0.0147) showing greater improvement. Consistent positive effects were also observed in patients with CHP and environmental/occupational lung disease. These data points, combined with substantial preclinical evidence of antifibrotic activity of treprostinil, suggest that Tyvaso may offer a treatment option for patients with fibrotic lung disease.