United Therapeutics Corporation Announces Breakthrough TETON-1 Results for Tyvaso® in Idiopathic Pulmonary Fibrosis (IPF)

Key Highlights

• TETON-1 pivotal study of nebulized Tyvaso® (treprostinil) met its primary endpoint for IPF, showing statistically significant and clinically meaningful improvement.
• Primary endpoint: Change in absolute forced vital capacity (FVC) of +130.1 mL compared to placebo (Hodges-Lehmann estimate, 95% CI: 82.2 to 178.1 mL; p <0.0001) at week 52.
• Secondary endpoints: Reduced risk of clinical worsening, improved time to first acute exacerbation, better quality of life (K-BILD score), and improved lung diffusion capacity (DLCO).
• Integrated analyses of TETON-1 and TETON-2 confirmed robust, statistically significant results across primary and most secondary endpoints.
• No new safety signals observed; Tyvaso was well-tolerated, consistent with previous studies.
• United Therapeutics plans to seek priority review for a supplemental New Drug Application (sNDA) with the FDA by the end of summer 2026 to add IPF indication for nebulized Tyvaso.
• Both the FDA and European Medicines Agency have granted orphan drug designation for treprostinil in IPF.
• Additional data to be presented at the American Thoracic Society Annual Meeting in Orlando, May 2026.
• Full TETON-2 results recently published in the New England Journal of Medicine.

Pivotal Study Details

The TETON-1 study enrolled 598 patients across the United States and Canada. This multicenter, randomized, double-blind, placebo-controlled Phase 3 trial evaluated the safety and efficacy of nebulized Tyvaso in IPF patients over 52 weeks. The primary endpoint was the change in absolute FVC from baseline to week 52, with secondary endpoints including time to clinical worsening, time to first acute exacerbation, overall survival, percent predicted FVC, quality of life (K-BILD), and DLCO.

Clinical and Market Significance

The TETON-1 study demonstrated unprecedented efficacy in IPF. Nebulized Tyvaso showed superiority over placebo for lung function preservation, reducing disease worsening and acute exacerbations, and improving quality of life. These benefits were seen across all patient subgroups regardless of background anti-fibrotic therapy, smoking status, or supplemental oxygen use. The integrated analysis with TETON-2 further reinforced the robustness of these findings.

According to United Therapeutics CEO Martine Rothblatt, “The unprecedented results of TETON-1, which surpassed even the overwhelmingly positive results of TETON-2, represent a profound step forward for people living with IPF, a devastating disease with few treatment options. In the past seven months, our three pivotal studies, TETON-1, TETON-2, and ADVANCE OUTCOMES, met their primary endpoints with p-values <0.0001, heralding a new era of greater growth for United Therapeutics.”

Dr. Steven D. Nathan, Chair of the TETON Steering Committee, commented: “IPF is a progressive, life-limiting disease for which existing treatments provide only modest benefit and are often accompanied by significant side effects. TETON-1 reinforces what was shown in TETON-2, with both studies demonstrating clinically meaningful outcomes in IPF patients with or without background anti-fibrotic therapy. Together, they showed better preservation of lung function, quality of life, reduced disease worsening, and reduced acute IPF exacerbations. These findings could fundamentally shift IPF management and be a game changer.”

Safety Profile

Tyvaso was well-tolerated in the study, with a safety profile consistent with previous Tyvaso studies and known prostacyclin-related side effects. No new safety signals were observed. Common side effects include cough, headache, throat irritation, nausea, flushing, syncope, dizziness, and diarrhea. Special warnings include risk of symptomatic hypotension, bleeding, and bronchospasm, particularly in patients with asthma or COPD. Drug interactions with CYP2C8 inhibitors and inducers may affect treprostinil exposure.

Market Opportunity

IPF affects between 0.33 and 4.51 people per 10,000 globally, with over 100,000 patients estimated in the United States. If approved, Tyvaso would be the first inhaled prostacyclin therapy for IPF, addressing pathways not currently targeted by existing therapies. Orphan drug designation from both the FDA and EMA could provide regulatory and commercial incentives, including market exclusivity.

Regulatory Plans and Next Steps

United Therapeutics plans to submit a supplemental New Drug Application (sNDA) for nebulized Tyvaso in IPF by the end of summer 2026 and will seek priority review. Additional results and integrated data from TETON-1 and TETON-2 will be presented at the American Thoracic Society Annual Meeting in May 2026. The ongoing TETON-PPF study is evaluating Tyvaso in progressive pulmonary fibrosis (PPF) globally.

Investor Implications

The results from TETON-1 are highly significant and potentially price sensitive for United Therapeutics shareholders:

• Demonstrated robust efficacy and safety in a large, multicenter, Phase 3 study for a new indication (IPF).
• Plans for priority FDA review and orphan drug designation could expedite approval and commercial launch.
• Potential for Tyvaso to become the first inhaled prostacyclin therapy for IPF, offering a novel mechanism of action and addressing unmet medical needs.
• Positive integrated results with TETON-2 and recent publication in NEJM add credibility and visibility to the clinical data.
• Management expects this to mark an “inflection point heralding a new era of greater growth” for United Therapeutics, suggesting strong commercial potential and future revenue growth.

Investors should note that forward-looking statements are subject to risks and uncertainties, including regulatory outcomes, competitive landscape, and market adoption. Actual results may differ from expectations.

About United Therapeutics

United Therapeutics is a public benefit corporation founded to discover cures for rare diseases, notably pulmonary arterial hypertension. The company is recognized for its innovative therapies and pioneering work in expanding the supply of transplantable organs. United Therapeutics operates with commitments to patients, integrity, long-term shareholder value, and sustainability.

Contact Information

Investor inquiries: https://ir.unither.com/contact-ir
Media inquiries: [email protected]

Disclaimer

This article is for informational purposes only and does not constitute investment advice or a recommendation to buy or sell securities. All forward-looking statements are subject to risks and uncertainties, and actual outcomes may differ materially. Investors are encouraged to review United Therapeutics’ filings with the SEC for additional risk factors and information.

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