United Therapeutics reports positive results for lung drug

United Therapeutics, a public benefit corporation with co-headquarters in Research Triangle Park, is poised to expand the use of its drug Tyvaso for treating a serious lung disease following positive clinical trial results.

The company said the nebulized form of Tyvaso, delivered as a fine mist inhaled into the lungs, met its primary efficacy endpoint for the treatment of idiopathic pulmonary fibrosis (IPF) in a phase 3 clinical trial. The drug, a prostacyclin known by its scientific name, treprostinil, achieved statistical significance for reducing the risk of clinical worsening and showed numerical improvement in other important secondary endpoints relative to placebo.

The results “represent a profound step forward for people living with IPF, a devastating disease with few treatment options,” said Martine Rothblatt, Ph.D., chairperson and chief executive officer of United Therapeutics. “We remain sincerely grateful to the patients, caregivers, and investigators who made this trial possible.”

The study results, along with positive results from a previous trial, “demonstrated not only better preservation of lung function, but also preservation of quality of life, as well as reduced disease worsening and reduced acute IPF exacerbations,” said Steven D. Nathan, M.D., Schar Chair, Advanced Lung Disease and Lung Transplant Program at Inova Fairfax Hospital and chair of the clinical trial steering committee. “These findings have the potential to fundamentally shift our approach to IPF management and could be a game changer.” 

The clinical results have “achieved statistical significance in endpoints that have never been attained in other IPF clinical trials,” said Peter Smith, Pharm.D., senior vice president of product development at United Therapeutics and the lead for the global clinical trial program. “These results provide a compelling body of evidence for nebulized Tyvaso’s differentiated direct lung delivery combined with multimodal activity across fibrotic, vascular, and inflammatory pathways that are not currently addressed by existing therapies.”

The company plans to seek priority review of a supplemental New Drug Application, to be submitted to the U.S. Food and Drug Administration (FDA) by the end of this summer. A successful review would add IPF to the labeled indications for nebulized Tyvaso, already FDA-approved for increasing exercise capacity in adults with Pulmonary Arterial Hypertension and Pulmonary Hypertension associated with Interstitial Lung Disease. 

Both the FDA and the European Medicines Agency have granted orphan drug designation for treprostinil to treat IPF. The designation provides incentives for the development of drugs or biologics that treat, diagnose, or prevent rare diseases affecting fewer than 200,000 people in the United States.  

IPF affects over 100,000 people in the U.S., with 25,000 to 50,000 new cases diagnosed annually. It mostly affects people over age 50. The disease is characterized by inflammation and scarring that inhibit the lungs’ ability to absorb oxygen from the air.

“IPF is a progressive, life-limiting disease for which existing treatments provide only modest benefit and are often accompanied by significant side effects,” Nathan said.

Treprostinil is a potent drug for various lung diseases because it opens blood vessels, reduces lung scarring, inhibits inflammation and prevents blood platelets from clumping. United Therapeutics markets inhalable dry powder, inhalable solution and injectable solution forms of the drug. 

The company reported $3.18 billion in revenue in 2025, up 11% from the prior year. 

United Therapeutics is a publicly held company with shares traded on the Nasdaq stock exchange under the symbol UTHR. It has co-headquarters in Research Triangle Park and Silver Spring, MD.