LEVosimendan to Improve Exercise Limitation in Patients With PH-HFpEF

Recruitment Status
RECRUITING
(See Contacts and Locations)Verified November 2025 by Tenax Therapeutics, Inc.
Sponsor
Tenax Therapeutics, Inc.
Information Provided by (Responsible Party)
Tenax Therapeutics, Inc.
Clinicaltrials.gov Identifier
NCT05983250
Other Study ID Numbers:
TNX-103-06
First Submitted
July 31, 2023
First Posted
August 8, 2023
Last Update Posted
February 17, 2026
Last Verified
November 2025

ClinicalTrials.gov processed this data on February 2026. Link to the current ClinicalTrials.gov record .

History of Changes

Study Details

Study Description

This is a Phase 3, double-blind, randomized, placebo-controlled study of oral levosimendan in patients with PH-HFpEF. There will be a Screening Period of up to 30 days. Subjects will provide written informed consent prior to completing any study procedures. Upon meeting all eligibility criteria, patients will continue to the 12-week randomized, double-blind treatment phase. Approximately 230 subjects will be randomized in a 1:1 ratio to receive an oral dose of levosimendan or placebo

All randomized subjects will have the option to enter the 92-week OLE following the completion of all study events at Week 12.

Condition or DiseaseIntervention/Treatment
Pulmonary Hypertension
Drug: PlaceboDrug: TNX-103

Study Design

Study TypeInterventional
Actual Enrollment230 participants
Design AllocationRandomized
Interventional ModelParallel Assignment
MaskingQuadruple
Primary PurposeTreatment
Official TitleA 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)
Study Start DateJanuary 9, 2024
Actual Primary Completion Date4mos 2w from now
Actual Study Completion Date2yrs 4mos from now

Groups and Cohorts

Group/CohortIntervention/Treatment
Placebo
Placebo
Drug: Placebo
Placebo
TNX-103
oral levosimendan
Drug: TNX-103
oral levosimendan 1 mg

Outcome Measures

Primary Outcome Measures
  1. Change in Six-minute walk distance
Secondary Outcome Measures
  1. KCCQ
    Change in KCCQ
  2. Clinical Worsening Events
  3. Change in NT-proBNP
    Decreases in NT-proBNP may indicate an improvement in symptoms
  4. Change NYHA functional class
    On a scale of I-IV. Lower scores may indicate improvement in symptoms

Eligibility Criteria

Ages Eligible for Study(Adult, Older Adult)
Sexes Eligible for StudyAll
Accepts Healthy VolunteersNo
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.

Contacts and Locations

Sponsors and CollaboratorsTenax Therapeutics, Inc.
Locations
Tenax Investigational Site | Tucson Arizona, United States, 85721Tenax Investigational Site | La Jolla California, United States, 92037Tenax Investigational Site | Los Angeles California, United States, 90033Tenax Investigational Site | Los Angeles California, United States, 90048Tenax Investigational Site | Sacramento California, United States, 95817Tenax Investigational Site | San Francisco California, United States, 94143Tenax Investigational Site | Torrance California, United States, 90502Tenax Investigational Site | Jacksonville Florida, United States, 32224Tenax Investigational Site | Winter Haven Florida, United States, 33881Tenax Investigational Site | Atlanta Georgia, United States, 30322Tenax Investigational Site | Chicago Illinois, United States, 60208Tenax Investigational Site | Chicago Illinois, United States, 60637Tenax Investigational Site | Galesburg Illinois, United States, 61401Tenax Investigational Site | Indianapolis Indiana, United States, 46202Tenax Investigational Site | Indianapolis Indiana, United States, 46260Tenax Investigational Site | Louisville Kentucky, United States, 40202Tenax Investigational Site | Boston Massachusetts, United States, 02114Tenax Investigational Site | Minneapolis Minnesota, United States, 55455Tenax Investigational Site | Rochester Minnesota, United States, 55905Tenax Investigational Site | St Louis Missouri, United States, 63136Tenax Investigational Site | Omaha Nebraska, United States, 68198Tenax Investigational Site | New York New York, United States, 10021Tenax Investigational Site | New York New York, United States, 10029Tenax Investigational Site | Rochester New York, United States, 14621Tenax Investigational Site | Roslyn New York, United States, 11576Tenax Investigational Site | Charlotte North Carolina, United States, 28203Tenax Investigational Site | Durham North Carolina, United States, 27710Tenax Investigational Site | Greensboro North Carolina, United States, 27401Tenax Investigational Site | Cincinnati Ohio, United States, 45267Tenax Investigational Site | Columbus Ohio, United States, 43214Tenax Investigational Site | Pittsburgh Pennsylvania, United States, 15212Tenax Investigational Site | Providence Rhode Island, United States, 02903Tenax Investigational Site | Charleston South Carolina, United States, 29425Tenax Investigational Site | Columbia South Carolina, United States, 29044Tenax Investigational Site | Dallas Texas, United States, 75204Tenax Investigational Site | Dallas Texas, United States, 75390Tenax Investigational Site | Lubbock Texas, United States, 79430Tenax Investigational Site | Plano Texas, United States, 75093Tenax Investigational Site | Murray Utah, United States, 84107Tenax Investigational Site | Richmond Virginia, United States, 23298Tenax Investigational Site | Madison Wisconsin, United States, 53792Tenax Investigational Site | Winnipeg Manitoba, Canada, Tenax Investigational Site | London Ontario, Canada, N6A 5A5Tenax Investigational Site | Toronto Ontario, Canada, M5A 4P5