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ClinicalTrials.gov 37 recruiting now early-phase tilt

Pulmonary Hypertension: early-phase trial registry

37 of 73 indexed Pulmonary Hypertension trials are currently recruiting, with more weight in Phase 1-2.

Corpus placement: #188 of 28,707 conditions by registered trial count.

73 US clinical trials · 37 currently recruiting · #188 of 28,707 conditions by registered trial count

Pulmonary Hypertension: 73 US clinical trials tracked, 37 recruiting.

Pulmonary Hypertension is the subject of 73 registered US clinical trials on ClinicalTrials.gov, 37 of them currently open to new participants. 11 are in Phase 3-4 (later-stage) and 23 in Phase 1-2 (earlier-stage). The most active sponsor is United Therapeutics, running 4 of these trials.

Enrollment posture brief

Registry condition pulmonary-hypertension

OPEN 37 | RECR 51% | LATE 11 | EARLY 23 | RANK #188 | SPON 4

Nearest open-share peer: Neuroendocrine Tumors (51% recruiting · 53 trials)

Solid Tumor, Adult65.8%Anatomic Stage II Breast Can54.1%Pulmonary Hypertension (this)51%Contraception21.9%Anemia18.9%
Open-enrollment share among volume-matched conditions near Pulmonary Hypertension

Pulmonary Hypertension lists 37 open slots (51% of 73 indexed trials). Peers are matched on registered volume, not therapeutic-area browse lists. How peer matching works →

Key findings

What ClinicalTrials.gov does not surface for Pulmonary Hypertension on its own pages , computed from the registry mirror as of 2026-08-08. Each line carries its own denominator so it can be quoted as it stands.

  1. Pulmonary Hypertension is recruiting above its size-band peers.

    37 of 73 indexed trials (50.7%) are open to enrollment, against a 39.7% average across 762 conditions with 20-99 trials. The peer set uses the same ClinicalTrials.gov-derived counts as this page.

  2. Sponsorship of Pulmonary Hypertension trials is spread across many organizations.

    United Therapeutics accounts for 4 of 73 trials (5.5%). 54 distinct sponsors appear on at least one study for this condition label.

  3. Typical Pulmonary Hypertension enrolment sits around 60 participants.

    Median target enrolment is 60 among the 73 trials that report a genuine target (sentinel values excluded). 40 of those (54.8%) plan for fewer than 100 participants.

  4. Pulmonary Hypertension splits between interventional and observational designs.

    45 interventional and 28 observational studies make up this index (61.6% interventional). Study type is sponsor-reported on ClinicalTrials.gov.

Phase 17Phase 216Phase 37Phase 44

Open and recent trials

73 total, page 2 of 2

COMPLETED Phase 3 235 participants

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

United Therapeutics

NCT00147199

COMPLETED 209 participants

Tricuspid Regurgitant Jet Velocity as an Independent Marker for Mortality in Sickle Cell Anemia

Namita Sood

NCT01783093

COMPLETED Phase 3 185 participants

Efficacy and Safety of Oral Bosentan in Pulmonary Arterial Hypertension Class II

Actelion

NCT00091715

COMPLETED 120 participants

Heart Disease in Sickle Cell Anemia

National Institutes of Health Clinical Center (CC)

NCT00113152

COMPLETED 71 participants

The Study Of CT Scans and Echo Parameters in Patients With PAH

Northwell Health

NCT00625963

COMPLETED Phase 1 59 participants

Nitric Oxide and Transfusion Therapy for Sickle Cell Patients With Pulmonary Hypertension

National Heart, Lung, and Blood Institute (NHLBI)

NCT00023296

COMPLETED 56 participants

Frailty in Children With Cardiac Disease

Children's Mercy Hospital Kansas City

NCT02999438

COMPLETED NA 35 participants

Noninvasive Cardiac Output Monitoring in Pulmonary Hypertension

Santa Barbara Cottage Hospital

NCT02951104

COMPLETED Phase 1 31 participants

Cardiopulmonary Function Assessment and NO-Based Therapies for Patients With Hemolysis-Associated Pulmonary Hypertension

National Heart, Lung, and Blood Institute (NHLBI)

NCT00352430

COMPLETED 29 participants

Pulmonary Hypertension, Hypoxia and Sickle Cell Disease

National Heart, Lung, and Blood Institute (NHLBI)

NCT00495638

COMPLETED Phase 4 25 participants

A Clinical Trial of Ambrisentan and Tadalafil in Pulmonary Arterial Hypertension Associated With Systemic Sclerosis

Johns Hopkins University

NCT01042158

COMPLETED NA 24 participants

Does Sildenafil Increase Exercise Performance in Air Pollution?

Marywood University

NCT00808912

COMPLETED NA 24 participants

Ex-vivo Perfusion and Ventilation of Lungs Recovered From Non-Heart-Beating Donors to Assess Transplant Suitability

University of North Carolina, Chapel Hill

NCT01615484

COMPLETED 24 participants

Cardiac MRI in Pulmonary Hypertension

University of California, San Francisco

NCT02485977

COMPLETED Phase 2 21 participants

11C-acetate/18Fluorodeoxyglucose-FDG PET/CT and Cardiac MRI in Pulmonary Hypertension

University of Pennsylvania

NCT01917136

COMPLETED Phase 1 20 participants

Effect of Bosentan on Exercise Capacity at High Altitude

VA Loma Linda Health Care System

NCT00432978

COMPLETED Phase 1 20 participants

Iloprost Effects on Gas Exchange and Pulmonary Mechanics

University of Oklahoma

NCT01274481

COMPLETED 20 participants

Effect of Endothelin-1 Receptor Blockade on Circulating Endothelial Microparticles Levels in Patients With Pulmonary Hypertension

University of California, San Francisco

NCT00675051

COMPLETED Phase 2 17 participants

Investigation of H01 in Adults With Pulmonary Hypertension Including Interstitial Lung Disease (The SATURN Study).

Stanford University

NCT05128929

COMPLETED Phase 2 16 participants

Ambrisentan (Letairis) for Sarcoidosis Associated Pulmonary Hypertension

Medical University of South Carolina

NCT00851929

COMPLETED Phase 4 12 participants

Exercise Induced Pulmonary Hypertension in Systemic Sclerosis and Treatment With Ambrisentan

University of California, Los Angeles

NCT01051960

COMPLETED Phase 4 10 participants

Study of Ranolazine in the Treatment of Pulmonary Hypertension Associated With Diastolic Left Ventricular Dysfunction

Boston University

NCT02133352

COMPLETED NA 6 participants

Cognitive Behavioral Therapy and Light Therapy

University of Pennsylvania

NCT05337943

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Phase Distribution

PhaseTrial count
Phase 1 7
Phase 2 16
Phase 3 7
Phase 4 4

Named interventions

Most-linked intervention names on Pulmonary Hypertension records (sponsor-reported on ClinicalTrials.gov). Counts are trial links, not unique products.

Placebo Drug
10 trials
Ambrisentan Drug
2 trials
Dry Powder Inhaler Device
2 trials
129Xe Hyperpolarized Drug
2 trials
Actigraph to check activity levels at home Device
1 trials
tadalafil and ambrisentan upfront combination therapy Drug
1 trials
Magnetic resonance Imaging Device
1 trials
INO Pulse - NO Delivery System Device
1 trials

US sites by state

Facility locations filed on Pulmonary Hypertension trials. A trial with sites in several states counts in each.

California 23 trials
Florida 16 trials
Pennsylvania 13 trials
Maryland 12 trials
Massachusetts 12 trials
Kentucky 12 trials
Colorado 12 trials
Arizona 12 trials

Source: ClinicalTrials.gov, National Library of Medicine. Data is informational only.

What to do with this Pulmonary Hypertension page

73 registered trials, 37 currently recruiting, is a starting point for a conversation, not a diagnosis or a recommendation.

  • 37 Pulmonary Hypertension trials are currently recruiting, check eligibility criteria before contacting a site. Browse recruiting trials
  • United Therapeutics sponsors the most Pulmonary Hypertension trials on record, review their full trial history before evaluating a specific study. See United Therapeutics's trials
  • Bring the specific trial ID (NCT number) to your own doctor before enrolling, this page is a directory, not medical guidance. Read the trial-finding guide

Trial and recruiting counts reflect ClinicalTrials.gov registry status as of the data vintage above; individual trial eligibility and enrollment status can change.

Every figure on PlainTrial is rendered directly from the ClinicalTrials.gov registry, no number is typed in by an editor. This Pulmonary Hypertension condition card totals 73 registered trials; most-linked intervention Placebo; top US site state California. See our editorial standards & corrections policy, the methodology behind these numbers, the data changelog, or report a data error.