Long-Term Open-Label Extension Study of Oral Levosimendan

March 17, 2026 updated by: Tenax Therapeutics, Inc.

A Multicenter, Open-Label, Long-Term Extension Study for Oral Levosimendan (TNX-103)

The purpose of this study is to provide continued access to treatment with oral levosimendan (TNX-103) and to describe the safety of continued use of TNX-103 in participants with pulmonary hypertension with heart failure with preserved left ventricular ejection fraction (PH-HFpEF) who received TNX-103 in a parent study.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

800

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Tenax Investigational Site
    • Minnesota
      • Minneapolis, Minnesota, United States, 55455
        • Tenax Investigational Site
      • Rochester, Minnesota, United States, 55905
        • Tenax Investigational Site
    • Missouri
      • St Louis, Missouri, United States, 63136
        • Tenax Investigational Site
    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Tenax Investigational Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Completed a TNX-103 parent study
  • Investigator confirmation that participant may derive clinical benefit from continued access to TNX-103
  • Requirements related to childbearing potential, contraception, and egg/sperm donation

Exclusion Criteria:

  • Investigator or Sponsor opinion that the participant is unsuitable due to safety, inability to comply, or factors that could compromise study integrity or participant well-being
  • Severe hepatic impairment or cirrhosis (Child-Pugh C) or active untreated hepatitis B or C with evidence of recent infection or viral replication
  • Estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m²
  • Pregnancy or breastfeeding in females

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: TNX-103
Open-label oral levosimendan 1-3mg
Drug: TNX-103
Open-label oral levosimendan 1-3mg

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The incidence (i.e., the percentage of patients who experience at least 1 occurrence) of select AE/SAEs
Time Frame: From enrollment through study completion (up to 3 years)
The incidence (i.e., the percentage of patients who experience at least 1 occurrence) of select AE/SAEs will be tabulated by system organ class and preferred term.
From enrollment through study completion (up to 3 years)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tenax Therapeutics, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 13, 2026

Primary Completion (Estimated)

March 1, 2029

Study Completion (Estimated)

March 1, 2029

Study Registration Dates

First Submitted

February 20, 2026

First Submitted That Met QC Criteria

February 25, 2026

First Posted (Actual)

February 27, 2026

Study Record Updates

Last Update Posted (Actual)

March 19, 2026

Last Update Submitted That Met QC Criteria

March 17, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TNX-103-08

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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