SILVER SPRING, Md. and RESEARCH TRIANGLE PARK, N.C., September 2, 2026
United Therapeutics Corporation announced that the U.S. Food and Drug Administration (FDA) has accepted its supplemental New Drug Application (sNDA) for nebulized Tyvaso® (treprostinil) Inhalation Solution as a treatment for idiopathic pulmonary fibrosis (IPF). The agency’s review is expected to be completed in late April 2027. Tyvaso is currently approved for pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease, but its use in IPF remains investigational. If approved, United Therapeutics said nebulized Tyvaso could become the first and only inhaled anti-fibrotic treatment for IPF.
TETON Program Supports FDA Filing
The sNDA is supported by positive results from the pivotal Phase 3 TETON-1 and TETON-2 studies, which evaluated nebulized Tyvaso in patients with IPF over 52 weeks. Combined analyses demonstrated statistically significant superiority over placebo for the primary endpoint, showing a 111.8 mL improvement in absolute forced vital capacity (FVC) from baseline to Week 52, with a 95% confidence interval of 79.7 to 144.0 mL and p<0.0001. The combined studies also achieved statistical significance across most key secondary endpoints, including reduced risk of clinical worsening and acute IPF exacerbation, as well as measures of percent-predicted FVC, lung diffusion capacity and health-related quality of life assessed using the King’s Brief Interstitial Lung Disease (K-BILD) questionnaire.
Nebulized Treprostinil Targets Multiple IPF Pathways
The TETON clinical program was established following a post-hoc analysis of the INCREASE study, which suggested that nebulized Tyvaso could improve FVC in patients with pulmonary hypertension associated with interstitial lung disease. TETON-1 enrolled patients in the United States and Canada, while TETON-2 enrolled patients outside those countries. Both were randomized, double-blind, placebo-controlled Phase 3 registration studies with absolute FVC change at Week 52 as the primary endpoint. Eligible participants could subsequently enter the ongoing TETON open-label extension study, designed to evaluate long-term safety and tolerability. United Therapeutics is also evaluating nebulized Tyvaso in progressive pulmonary fibrosis (PPF) in the TETON-PPF program, for which enrollment is complete.
Advertisement
FDA Decision Could Expand IPF Treatment Options
Idiopathic pulmonary fibrosis is a progressive lung-scarring disease that gradually impairs the lungs’ ability to transfer oxygen and can ultimately lead to respiratory failure and death. United Therapeutics estimates that at least 100,000 people in the United States are living with IPF. The company believes nebulized Tyvaso’s direct delivery to the lungs and activity across fibrotic, vascular and inflammatory pathways could provide a differentiated treatment approach for patients with the disease. Treprostinil has received orphan designation from both the FDA and European Medicines Agency for IPF. With the sNDA now accepted for review and an anticipated FDA action in April 2027, the regulatory decision will determine whether nebulized Tyvaso can expand beyond its current pulmonary hypertension indications into the treatment of IPF.
Source:United Therapeutics, press relese
