United Therapeutics Announces FDA Clearance to Proceed with SUMMIT Clinical Trial for Treprostinil SMI in PH-COPD

The development of a soft mist inhaler (SMI) represents a further advancement of treprostinil delivery devices to potentially address a wider range of patient tolerability profiles

A soft mist formulation may be beneficial for patients with pulmonary hypertension associated with chronic obstructive pulmonary disease (PH-COPD), who are susceptible to cough and bronchospasm from inhaled therapies

Treprostinil SMI has the potential to be the first FDA-approved therapy specifically indicated for PH-COPD

SILVER SPRING, Md. & RESEARCH TRIANGLE PARK, N.C., October 19, 2026--United Therapeutics Corporation (Nasdaq: UTHR), a public benefit corporation, today announced that the U.S. Food and Drug Administration (FDA) has granted clearance under the company's investigational new drug application to proceed with the SUMMIT clinical trial of treprostinil SMI in PH-COPD.

The phase 2, 16-week, double blind SUMMIT study will evaluate the safety and tolerability of treprostinil SMI in approximately 40 patients with PH-COPD. The study's secondary endpoints will evaluate the efficacy of treprostinil SMI on exercise capacity and N-terminal pro-B-type natriuretic peptide (NT-proBNP), a critical biomarker for heart failure. Eligible patients in the SUMMIT study will be able to enroll in an open-label extension study to evaluate the long-term safety, tolerability, and efficacy of treprostinil SMI.

Assuming a successful outcome in the SUMMIT study, United Therapeutics anticipates commencing a subsequent phase 3 registration study for treprostinil SMI in PH-COPD in 2028.

"PH-COPD is a serious, life-threatening condition with no approved treatments. We believe that inhaled treprostinil, delivered via a soft mist inhaler, may benefit the carefully defined SUMMIT PH-COPD patient population by directly targeting the pulmonary vasculature. Our hope is that treprostinil SMI will offer meaningful benefit and reduce disease burden for PH-COPD patients who deserve a treatment option that addresses their significant unmet needs," said Leigh Peterson, Ph.D., head of pharmaceutical and xenograft development at United Therapeutics."

"I believe this development will lead to an exponential inflection point for United Therapeutics," said Martine Rothblatt, Ph.D., its Chairperson and Chief Executive Officer. "We estimate PH-COPD could impact five to ten times the number of patients than the conditions all of our current therapies are approved to treat today. Upon successful completion of the SUMMIT program and approval by the FDA, we expect United Therapeutics will become a several times larger company than it is today."