Enrollment complete for Phase 3 trial testing Tyvaso in IPF patients
Data expected in second half of 2025, United Therapeutics says
Enrollment is complete for a Phase 3 clinical trial testing Tyvaso (treprostinil) inhalation solution for idiopathic pulmonary fibrosis (IPF), United Therapeutics, the therapy’s developer, said.
The TETON 2 study (NCT05255991) will evaluate the treatment’s safety and efficacy in 597 adults with IPF, 40 years and older, at sites outside the U.S. and Canada. Top-line data are expected in the second half of 2025.
A parallel Phase 3 trial, TETON 1 (NCT04708782), is still recruiting IPF patients at sites in the U.S. and Canada.
Tyvaso is approved in the U.S. for treating pulmonary arterial hypertension and improving exercise ability in people with pulmonary hypertension associated with interstitial lung disease (ILD), a condition in which blood pressure increases in the lungs due to inflammation and tissue scarring, or fibrosis.
It is not currently approved to treat IPF patients who do not have pulmonary hypertension.
Trials aimed at ‘underserved’ population
“Our continued goal with the TETON program is to demonstrate that inhaled treprostinil can lead to better patient outcomes in this underserved, vulnerable patient population with fibrotic lung disease,” Peter Smith, United Therapeutics’ vice president of product development and global TETON program lead, said in a company press release.
IPF is a type of ILD of unknown cause, marked by lung scarring that makes it hard for patients to breathe. As IPF progresses, some patients develop pulmonary hypertension, or high blood pressure in the blood vessels that supply the lungs.
Tyvaso works by mimicking the activity of prostacyclin, a naturally occurring molecule that promotes blood vessel widening, thereby improving blood flow and reducing blood pressure. The therapy, delivered directly to the lungs using a portable, hand-held device, is designed to improve patients’ exercise and breathing capacity.
While Tyvaso isn’t approved for IPF patients who don’t have pulmonary hypertension, the TETON 1 and 2 trials are testing the therapy in those with IPF regardless of whether they have high blood pressure in the lungs.
In both studies, participants are randomly assigned to receive inhaled Tyvaso four times daily, or a placebo, for one year. Each inhalation delivers about 6 micrograms of treprostinil, and patients will start with three inhalations each administration (12 daily), up to a target of 12 inhalations four times per day, or the maximum tolerated dose.
The trials’ main goal is to assess changes in lung function by analyzing changes in forced vital capacity, a measure of lung function that assesses the total amount of air a person is capable of exhaling after a deep breath.
Secondary measures include time to clinical worsening and first acute exacerbation, changes in other lung function measures, disease symptoms, a blood marker of heart failure, and supplemental oxygen use, as well as survival.
The treatment’s safety, including adverse events, vital signs, and laboratory and heart function parameters will also be evaluated.
“On behalf of my colleagues at United Therapeutics, I’d like to thank the patients and investigators around the world for the courage and determination to participate in the potentially revolutionary TETON 2 study,” Smith said.
About the Author
