Shares of United Therapeutics Corporation (NASDAQ:UTHR) climbed about 12% on Monday after the company reported that its pivotal TETON-1 study of Tyvaso successfully achieved its primary endpoint in patients with idiopathic pulmonary fibrosis (IPF).
The inhaled therapy demonstrated clear superiority over placebo in improving absolute forced vital capacity, showing a treatment difference of 130.1 mL. The drug also reduced the risk of clinical worsening in patients with IPF, with results surpassing those observed in the earlier TETON-2 trial.
Tyvaso also reached statistical significance in lowering the likelihood of clinical deterioration and delivered numerical improvements across several secondary measures compared with placebo. These included time to first acute IPF exacerbation, percent predicted FVC, K-BILD quality-of-life scores, and DLCO measurements.
Combined analysis of data from both the TETON-1 and TETON-2 trials showed a statistically significant benefit versus placebo for the primary endpoint, with an improvement of 111.8 mL in absolute FVC from baseline to week 52. Positive effects were observed across all patient subgroups, including individuals receiving background therapies such as nintedanib or pirfenidone.
The nebulized formulation of Tyvaso was generally well tolerated, and its safety profile aligned with previous studies of the drug. Researchers reported no new safety concerns.
United Therapeutics said it intends to request priority review from the U.S. Food and Drug Administration for a supplemental New Drug Application expected to be submitted by the end of the summer, seeking approval to include IPF among the labeled indications for nebulized Tyvaso. Both the FDA and the European Medicines Agency have already granted orphan drug designation to treprostinil for the treatment of IPF.
Further findings from the TETON-1 study, along with results from the combined analysis of both trials, are scheduled to be presented at the American Thoracic Society Annual Meeting in Orlando in May 2026.