United Therapeutics announces TETON-2 study meets primary endpoint

United Therapeutics (UTHR) announced that its TETON-2 study evaluating the use of nebulized Tyvaso Inhalation Solution for the treatment of idiopathic pulmonary fibrosis met its primary efficacy endpoint of demonstrating improvement in absolute forced vital capacity relative to placebo. Tyvaso demonstrated superiority over placebo for the change in absolute FVC by 95.6 mL from baseline to week 52 in patients with IPF. Benefits of Tyvaso were observed across all subgroups, such as use of background therapy, smoking status, and supplemental oxygen use. Statistically significant improvements relative to placebo were also observed in most secondary endpoints, including time to first clinical worsening event, as well as changes from baseline to week 52 in percent predicted FVC, King’s Brief Interstitial Lung Disease quality of life questionnaire, and diffusion capacity of lungs for carbon monoxide. While not statistically significant, both time to first acute exacerbation of IPF and overall survival at week 52 trended in favor of Tyvaso. Treatment with Tyvaso was well-tolerated, and the safety profile was consistent with previous Tyvaso studies and known prostacyclin-related adverse events. No new safety signal was seen. United Therapeutics intends to use the data from both the TETON-2 study and the ongoing TETON-1 study of nebulized Tyvaso to support a supplemental new drug application to the FDA to add IPF to the labeled indications for nebulized Tyvaso. United Therapeutics plans to meet with the FDA before the end of the year to discuss ways to potentially expedite the regulatory review process when TETON-1 results are available. Data readout from TETON-1 is expected in the first half of 2026. Both the FDA and the European Medicines Agency have granted orphan designation for treprostinil to treat IPF.