Tiprelestat Versus Placebo When Added to Standard of Care for the Treatment of Pulmonary Arterial Hypertension (PAH)

What Was Tested

In this phase 2 trial, researchers set out to test Elafin.

It had three arms (groups): one (experimental), one (experimental) and one (placebo comparator).

Participants receive tiprelestat injection daily for 168 days.

Participants receive tiprelestat injection daily for 168 days.

Participants receive placebo injection (matching tiprelestat) daily for 168 days.

The registry classes the interventions as drug.

Who Took Part

90 planned participants were the target.

It was open to people of any sex aged from 18 years up to 75 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Adults age 18 to 75 years. Willingness to give written informed consent prior to any study-related procedures being performed and to be able to adhere to the study restrictions and examination schedule. Diagnosis of WHO Group I PAH. 6MWD ≥100 and ≤500 meters at screening. Willing to adhere to study restrictions and examination schedule.

The full record lists 10 inclusion and 23 exclusion criteria; among the exclusions: diagnosis of who group 2 - 5 pulmonary hypertension; participation in another clinical trial, or experimental use, involving a pah investigational drug or device within the last 3 months; moderate or severe aortic or mitral valve disease.

How the Study Was Run

It was run as a randomized, parallel-group and triple-blind study.

Random assignment meant chance, not the researchers, decided who got Elafin and who got the comparison, which limits bias.

The Elafin group and the comparison group ran side by side rather than switching.

Blinding on both sides kept the participants and researchers unaware of who received Elafin.

Those kept unaware of assignments: participant, care provider and investigator.

It started in 2026-07 with completion listed for 2030-02.

It ran at 10 sites in United States (10).

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Change in Pulmonary Vascular Resistance (PVR) (time frame: Baseline to week 24).

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Elafin in 90 people.

Its status is not yet recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Elafin compound page, all human trials.