Clinical Investigation Into Inhaled Treprostinil Sodium in Patients With Severe Pulmonary Arterial Hypertension (PAH) (TRIUMPH)

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United Therapeutics

Status and phase

Phase 3


Pulmonary Hypertension


Drug: Inhaled treprostinil
Drug: Placebo inhalation solution

Study type


Funder types




Details and patient eligibility


This is a double-blind placebo-controlled clinical investigation into the efficacy and tolerability of inhaled treprostinil in patients with severe pulmonary arterial hypertension. The primary outcome is the change in 6-minute walk distance from baseline to week 12.

Full description

Patients who have been on a stable dose of 125 mg twice daily (bid) of bosentan or any stable dose of sildenafil for at least three months prior to study start were randomized to either treprostinil inhalation solution or matching placebo. Administration of study medication was performed by inhalation with the OPTINEB™ ultrasonic nebulizer. The proposed dosing regimen was four times daily-upon awakening, at midday, evening (dinner time) and bedtime. After a patient has completed the twelve-week study period, they were given the option of enrolling into an open-label extension study.


235 patients




18 to 75 years old


No Healthy Volunteers

Inclusion criteria

  • Clinically stable, pulmonary arterial hypertension diagnosed as either idiopathic or familial PAH, collagen vascular disease associated PAH, HIV PAH, or PAH induced by anorexigens, New York Heart Association (NYHA) Class III or Class IV.
  • Been on a stable dose of 125 mg twice daily (bid) of bosentan OR any stable dose of sildenafil for at least three months prior to study start
  • An unencouraged six minute walk test (6MWT) of between 200 and 450 meters at screening
  • Cardiac catheterization within the past 13 months consistent with PAH, specifically mean pulmonary artery pressure (PAPm) ≥25 mmHg (at rest), pulmonary capillary wedge pressure (PCWP) (or left ventricular end diastolic pressure) ≤15 mmHg, and pulmonary vascular resistance (PVR) >3 mmHg/L/min
  • Within the past 12 months, patients must have had a chest radiograph consistent with the diagnosis of PAH
  • Willing and able to follow all study procedures

Exclusion criteria

  • Considering pregnancy, are pregnant and/or lactating
  • PAH due to conditions other than noted in the above inclusion criteria.
  • Have had any change in or discontinued any PAH medication within the last three months, including but not limited to endothelin receptor antagonist (ERA), or calcium channel blockers (CCB) (with the exception of anticoagulants)
  • Have received any prostanoid within the 30 days before screening or are scheduled to receive any during the course of the study
  • Have received any investigational medication within 30 days prior to the start of this study or are scheduled to receive another investigational drug during the course of this study
  • Have a known intolerance to any drug, especially to treprostinil sodium or prostanoids
  • Have an increased risk of hemorrhage
  • Have a new type of chronic therapy (e.g., a different category of vasodilator, diuretic) for PAH added within the last month, except anticoagulants
  • Have any musculoskeletal disease or any other disease that would limit ambulation.

Trial design

Primary purpose




Interventional model

Parallel Assignment


Quadruple Blind

235 participants in 2 patient groups, including a placebo group

Inhaled treprostinil
Experimental group
0.9 mg/mL treprostinil for inhalation supplied in 2.9mL ampoules for use in ultra sonic nebulizer
Drug: Inhaled treprostinil
Placebo Comparator group
Placebo inhalation solution for use in ultrasonic nebulizer
Drug: Placebo inhalation solution

Trial contacts and locations



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