United Therapeutics Corporation (NASDAQ: UTHR) announced that the U.S. Food and Drug Administration has accepted a supplemental New Drug Application for nebulized Tyvaso (treprostinil) Inhalation Solution as a treatment for idiopathic pulmonary fibrosis (IPF).

The FDA is expected to complete its review in late April 2027. Nebulized Tyvaso has not been approved for IPF and remains investigational for this indication.

The application was based on results from the phase 3 TETON-1 and TETON-2 clinical studies. Combined analyses of the two trials met the primary efficacy endpoint, with nebulized Tyvaso showing statistically significant superiority over placebo in change in absolute forced vital capacity of 111.8 mL.

The combined analyses also showed statistical significance for several key secondary endpoints, including reduced risk of a clinical worsening event, reduced risk of acute IPF exacerbation, and changes in percent of predicted forced vital capacity, quality of life scores, and diffusion capacity of lungs for carbon monoxide.

TETON-1 data were presented at the 2026 annual meeting of the American Thoracic Society. TETON-2 data were published in The New England Journal of Medicine. Combined results from both trials were presented at the same conference and simultaneously published in The New England Journal of Medicine.

Both the FDA and the European Medicines Agency have granted orphan designation for treprostinil to treat IPF.