Clinical Trial in Patients With Barth Syndrome- 4TAZPower (4TAZPower)

September 15, 2026 updated by: Stealth BioTherapeutics Inc.

Phase 3b/4, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled, Trial to Evaluate the Efficacy and Safety of Daily Subcutaneous Injections of Elamipretide in Patients With Genetically Confirmed Barth Syndrome

Phase 3b/4, randomized, double-blind, parallel-group, placebo-controlled clinical trial to evaluate the efficacy, safety, and pharmacokinetics of a once daily SC injection of elamipretide in subjects with genetically confirmed BTHS for 72 weeks. The primary trial objective is to confirm the efficacy of elamipretide which is approved in the United States(FORZINITY™) under the accelerated approval based on an improvement in knee extensor muscle strength, an intermediate clinical endpoint.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The SPIBA-401 trial is a post marketing Phase 3b/4, randomized, double-blind, parallel-group, placebo-controlled clinical trial to evaluate the efficacy, safety, and pharmacokinetics of a once daily subcutaneous (SC) injection of elamipretide in subjects with genetically confirmed Barth syndrome (BTHS) for 72 weeks. The primary trial objective is to confirm the efficacy of elamipretide which is approved in the United States under the name FORZINITY™ as a mitochondrial cardiolipin binder indicated to improve muscle strength in adult and pediatric patients with Barth syndrome weighing at least 30 kg. This indication is approved in the United States under accelerated approval based on an improvement in knee extensor muscle strength, an intermediate clinical endpoint.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
48

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

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

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Canada
    • Alberta
      • Calgary, Alberta, Canada
        • Recruiting
        • Metabolics and Genetics in Canada (MAGIC)
        • Contact:
  • United Kingdom
      • Bristol, United Kingdom
        • Recruiting
        • Bristol Royal Hospital for Children Upper Maudlin Street Paul O'Gorman Building
        • Contact:
  • United States
    • Massachusetts
      • Needham, Massachusetts, United States, 02494
        • Terminated
        • Trial Not Offered in the U.S

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. Willing and able to provide signed informed consent form (ICF) prior to participation in any trial-related procedures. If applicable, informed consent in writing from parent(s) or legally-acceptable representative(s) and, informed assent from subject (if age appropriate according to local requirements) should be provided.
  2. Agrees to adhere to the trial requirements for the length of the trial.
  3. Must have genetically confirmed Barth Syndrome (pathogenic variant in the TAZ gene)
  4. Male aged ≥ 5 years at time of the Screening Visit
  5. Left Ventricular Ejection fraction of ≥ 50% by 3-D Echocardiogram at the Screening Visit.
  6. For subjects with a medical history of cardiomyopathy, must be on a stable regimen (unchanged and constant) of background heart failure medications for at least 3 months prior to the Screening Visit.
  7. Able to administer Investigational Medicinal Product (IMP) or have an appropriate designee who can administer the IMP (i.e., a capable family member or a caregiver).
  8. Subjects with female partners of childbearing potential must be willing to use a highly effective method of contraception (e.g., abstinence, dual method of contraception) from the date they sign the ICF until 28 days after the last dose of IMP.

Key Exclusion Criteria:

  1. Unable to perform the required functional tests or undergo echocardiography.
  2. History of solid organ transplant, except successful cardiac transplantation > 12 months prior to screening, if, in the opinion of the Investigator, there is no evidence of organ rejection and post-transplant pharmacotherapy, is stable, and does not pose additional safety risk to participant.
  3. Patients with an implantable cardioverter defibrillator (ICD) and with a known occurrence of ICD discharge in the 3 months prior to the Screening Visit.
  4. Current placement on the waiting list for heart transplantation.
  5. Hospitalization for heart failure within 6 months prior to the Screening Visit.
  6. Any disease or medical condition that in the opinion of the Investigator would prevent the subject from successfully participating in the trial and reliably completing the assessments or might confound trial results.
  7. Has a history of a systemic eosinophilic illness
  8. Estimated Glomerular Filtration Rate (eGFR) of < 30 mL/min at the Screening Visit (using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2021 formula for subjects >16 years of age and the Schwartz 2009 formula for subjects 5-16 years of age).
  9. Active malignancy or any other cancer from which the subject has been cancer-free for < 2 years. Localized squamous or non-invasive basal cell skin carcinomas are allowed, if appropriately treated prior to Screening.
  10. Participation in other investigational drug or device clinical trials within 30 days or 5 half-lives (whichever is longer) of Screening; or is currently enrolled in a non-interventional clinical trial that, in the opinion of the Investigator, may be potentially confounding to the results of the current trial.
  11. History of allergic reaction to the IMP or any of its components.
  12. Prior participation in any elamipretide trial or expanded access programs.

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Elamipretide
Elamipretide - aqueous, sterile 5.0 mL single-patient, ready to use, multi-dose glass vial containing 3.5 mL of elamipretide solution (elamipretide [80 mg/mL],
Drug: Elamipretide
sub cutaneous injection
Other Names:
  • elamipretide hydrochloride
Placebo Comparator: Placebo
Matching Placebo-aqueous, sterile 5.0 mL single-patient, ready to use, multi-dose glass vial containing will be composed of 3.5mL of sodium chloride, phosphate buffer, and benzyl alcohol similar to excipients in active drug but without the active drug substance
Drug: Placebo
sub cutaneous injection

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Primary Efficacy End Point
Time Frame: 72 weeks
-change in the composite normalized score of the three functional tests: Six-minute walk test (6MWT), the triple-timed up and go test (3TUG), and the Five times sit-to-stand test (5XSST) from baseline to 72 weeks of treatment
72 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Secondary Efficacy End Point 1
Time Frame: 72 weeks
- Change in 6Minute Walk Test from Baseline to Week 72
72 weeks
Secondary Efficacy End Point 2
Time Frame: 72 weeks
-Change in 3Timed Up and Go Test from Baseline to Week 72
72 weeks
Secondary Efficacy End Point 3
Time Frame: 72 weeks
-Change in 5XSit to Stand Test from Baseline to Week 72
72 weeks
Secondary Efficacy End Point 4
Time Frame: 72 weeks
-Change in Patient Global Impression of Severity Scale (PGI-S) score from Baseline to Week 72
72 weeks
Secondary Efficacy End Point 5
Time Frame: 72 weeks
Change in Clinician Global Impression of Severity Scale (CGI-S) score from Baseline to Week 72
72 weeks
Secondary Efficacy End Point
Time Frame: 72 weeks
Change in knee extensor muscle strength as measured by handheld dynamometry (HHD)from Baseline to Week 72
72 weeks
Secondary Efficacy End Point 6
Time Frame: 72 weeks
-Change in hip flexor muscle strength as measured by HHD from Baseline to Week 72
72 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Safety End Point Adverse Event Reporting
Time Frame: 72weeks
-Report the # of subjects with adverse events and incidence and severity of such adverse events (AEs)
72weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Stealth BioTherapeutics Inc.

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Rekha Sathyanarayana, Stealth BioTherapeutics 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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 2, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 30, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 30, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 12, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 8, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 15, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 15, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SPIBA-401

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

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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