United Therapeutics Corporation (Nasdaq: UTHR) announced that its pivotal TETON-2 clinical trial of Tyvaso® (treprostinil) Inhalation Solution for idiopathic pulmonary fibrosis (IPF) met its primary endpoint, showing significant improvement in lung function compared with placebo.
Over 52 weeks, patients receiving nebulized Tyvaso demonstrated an improvement of 95.6 mL in absolute forced vital capacity (FVC) versus placebo (p <0.0001). Benefits were consistent across all subgroups, including those receiving background therapy (nintedanib, pirfenidone, or none), smokers and nonsmokers, and patients with or without supplemental oxygen.
Secondary Endpoints Also Show Positive Results
Statistically significant improvements relative to placebo were observed for:
- Time to first clinical worsening event
- Change in percent predicted FVC
- Quality of life, as measured by the King’s Brief Interstitial Lung Disease (K-BILD) questionnaire
- Diffusion capacity of the lungs for carbon monoxide (DLCO)
While not statistically significant, trends in favor of Tyvaso were also seen in time to first acute exacerbation of IPF and overall survival at 52 weeks. Treatment was well-tolerated, with a safety profile consistent with prior Tyvaso studies and no new safety signals.
A Potential Step Forward for IPF Patients
“It is a profound honor to witness the power of scientific innovation realized for patients in need,” said Martine Rothblatt, Ph.D., chairperson and CEO of United Therapeutics. “TETON-2’s successful outcome affirms the anti-fibrotic power of Tyvaso. We have unlocked new hope for patients with IPF and their families.”
Peter Smith, Pharm.D., senior vice president of product development and global lead for the TETON program, added: “These overwhelmingly positive data send a clear signal of the potential benefits of Tyvaso for patients with IPF. These results have the potential to reshape the treatment of IPF, extending new opportunities to a much broader patient population than ever before.”
Steven D. Nathan, M.D., chair of the TETON Steering Committee and director of the Advanced Lung Disease and Lung Transplant Program at Inova Fairfax Hospital, emphasized the clinical significance: “Existing IPF treatments offer only modest benefits, often with challenging side effects. These results represent a major step forward, giving us hope for improving outcomes in patients who desperately need better options.”
Next Steps
United Therapeutics plans to use data from TETON-2, together with results from the ongoing TETON-1 study, to support a supplemental New Drug Application to the FDA seeking to add IPF to Tyvaso’s labeled indications. The company expects TETON-1 results in the first half of 2026.
Both the FDA and European Medicines Agency have granted orphan drug designation to treprostinil for the treatment of IPF. Additional TETON-2 data will be presented at the European Respiratory Society Congress in Amsterdam on September 28, 2025.
