Home › Trials › NCT05983250

Using levosimendan to help patients with pulmonary hypertension and heart failure exercise better

A Phase 3, Double-Blind, Randomized, Placebo-Controlled Study of Levosimendan in Pulmonary Hypertension Patients With Heart Failure With Preserved Left Ventricular Ejection Fraction (PH-HFpEF)

PHASE3 · Tenax Therapeutics, Inc. · NCT05983250

This study is testing if an oral medication called levosimendan can help people with pulmonary hypertension and heart failure exercise better than a placebo.

Quick facts

PhasePHASE3
Study typeInterventional
Enrollment230 (estimated)
Ages18 Years to 85 Years
SexAll
SponsorTenax Therapeutics, Inc. (industry)
Locations44 sites (Tucson, Arizona and 43 other locations)
Trial IDNCT05983250 on ClinicalTrials.gov

What this trial studies

This Phase 3 clinical trial evaluates the effectiveness of oral levosimendan (TNX-103) compared to a placebo in patients diagnosed with pulmonary hypertension associated with heart failure with preserved ejection fraction (PH-HFpEF). The study involves a 30-day screening period followed by a 12-week randomized, double-blind treatment phase where approximately 230 participants will be assigned to receive either the medication or placebo. The primary outcome measure is the change in the 6-Minute Walk Distance (6 MWD) from Day 1 to Week 12. Participants may also have the opportunity to enter a 92-week open-label extension phase after the initial study period.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 to 85 with NYHA Class II or III symptoms and a confirmed diagnosis of WHO Group 2 PH-HFpEF.

Not a fit: Patients with pulmonary hypertension from other WHO groups or those with significant structural heart disease or pre-existing lung conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could significantly improve exercise capacity and quality of life for patients with PH-HFpEF.

How similar studies have performed: While this approach is being tested in this specific context, similar studies have shown promise in improving exercise capacity in heart failure patients, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Men or women, greater than or equal to18 to 85 years of age.
2. NYHA Class II or III or NYHA class IV symptoms.
3. A diagnosis of World Health Organization (WHO) Group 2 PH-HFpEF with qualifying hemodynamics
4. Qualifying Baseline RHC.
5. Qualifying echocardiogram
6. Qualifying 6-MWD
7. A 48-hour ambulatory cardiac rhythm monitor during the Screening Period.
8. Requirements related to child bearing potential, contraception, and egg/sperm donation

Exclusion Criteria:

1. A diagnosis of PH WHO Groups 1, 3, 4, or 5.
2. Echocardiographic evidence for hypertrophic cardiomyopathy, restrictive cardiomyopathy, constrictive pericarditis, cardiac amyloidosis, or infiltrative cardiomyopathy
3. Structural heart repair or replacement of the aortic valve or mitral valve (surgical or percutaneous). OR, planned valve intervention. OR, the presence of significant valve disease
4. A diagnosis of pre-existing lung disease
5. History of severe allergic or anaphylactic reaction or hypersensitivity to the excipients in the investigational product.
6. Major surgery within 60 days.
7. Prior heart, lung, or heart-lung transplants or life expectancy of \<12 months
8. History of clinically significant other diseases that may limit or complicate participation in the study.

Where this trial is running

Tucson, Arizona and 43 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Pulmonary Hypertension, HFpEF, Pulmonary hypertension group 2, PH-HFpEF, Heart Failure

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.