Barth SyndromePhase 44TAZPowerNCT07531251
Clinical Trial in Patients With Barth Syndrome- 4TAZPower
A Phase 4 study testing Elamipretide in people with Barth Syndrome, run by Stealth BioTherapeutics Inc. at 3 sites in 3 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 5 to 55 years, men only
- Conditions the study is for
- Barth Syndrome
- What is being tested?
- Elamipretide
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 48 participants
- Where
- 3 sitesin 3 countries
- Study dates
- 2 Jul 2026to 30 Nov 2029
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 5 to 55 years
- Men only
- No healthy volunteers
- Child, Adult
Who may be able to join
- 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.
- Agrees to adhere to the trial requirements for the length of the trial.
- Must have genetically confirmed Barth Syndrome (pathogenic variant in the TAZ gene)
- Male aged ≥ 5 years at time of the Screening Visit
- Left Ventricular Ejection fraction of ≥ 50% by 3-D Echocardiogram at the Screening Visit.
- 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.
- 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).
- 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.
Who cannot join
- Unable to perform the required functional tests or undergo echocardiography.
- 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.
- Patients with an implantable cardioverter defibrillator (ICD) and with a known occurrence of ICD discharge in the 3 months prior to the Screening Visit.
- Current placement on the waiting list for heart transplantation.
- Hospitalization for heart failure within 6 months prior to the Screening Visit.
- 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.
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- Has a history of a systemic eosinophilic illness
- 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).
- 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.
- 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.
- History of allergic reaction to the IMP or any of its components.
- Prior participation in any elamipretide trial or expanded access programs.
Trial locations and contacts
3 sites in 3 countries. Contact the study team or a site near you to ask about taking part.
Lani Glennon contact
3 sites in 3 countries
United States1 site
- Terminated
Trial Not Offered in the U.S
Needham, Massachusetts, 02494
Canada1 site, 1 recruiting
- Recruiting
Metabolics and Genetics in Canada (MAGIC)
Calgary, Alberta
Adley Mok, +1 587-885-3158, clinic@magiccalgary.ca
United Kingdom1 site, 1 recruiting
- Recruiting
Bristol Royal Hospital for Children Upper Maudlin Street Paul O'Gorman Building
Bristol
Ros Strang, 0+44 1173 429210, rosalind.strang@uhbw.nhs.uk
About this study
Official title: 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.
Read the 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.
- Conditions
- Barth Syndrome
- Being tested
- Elamipretide, Placebo
- Keywords
- BTHS, Ultra Rare X-Linked Mitochondrial Disorder, Genetic Defect in TAZ Gene
- Medical subject headings
- Barth Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ElamipretideDrug
Also called elamipretide hydrochloride
sub cutaneous injection
PlaceboDrug
sub cutaneous injection
| Study group | Role | What they receive |
|---|---|---|
| Elamipretide | Active comparator | 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], Receives: Drug: Elamipretide |
| Placebo | Placebo comparator | 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 Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary Efficacy End Point
-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
Measured: 72 weeks
Secondary outcomes (7)
Secondary Efficacy End Point 1
- Change in 6Minute Walk Test from Baseline to Week 72
Measured: 72 weeks
Secondary Efficacy End Point 2
-Change in 3Timed Up and Go Test from Baseline to Week 72
Measured: 72 weeks
Secondary Efficacy End Point 3
-Change in 5XSit to Stand Test from Baseline to Week 72
Measured: 72 weeks
Secondary Efficacy End Point 4
-Change in Patient Global Impression of Severity Scale (PGI-S) score from Baseline to Week 72
Measured: 72 weeks
Secondary Efficacy End Point 5
Change in Clinician Global Impression of Severity Scale (CGI-S) score from Baseline to Week 72
Measured: 72 weeks
Secondary Efficacy End Point
Change in knee extensor muscle strength as measured by handheld dynamometry (HHD)from Baseline to Week 72
Measured: 72 weeks
Secondary Efficacy End Point 6
-Change in hip flexor muscle strength as measured by HHD from Baseline to Week 72
Measured: 72 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Apr 2026
- Study start2 Jul 2026
- Primary completion30 Sep 2029 (estimated)
- Study completion30 Nov 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Barth SyndromeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- 1:1 Randomization
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Stealth BioTherapeutics Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Rekha Sathyanarayana, Study director, Stealth BioTherapeutics Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07531251
- Sponsor's protocol ID
- SPIBA-401
- Acronym
- 4TAZPower
- Status last verified
- Sep 2026
- First submitted
- 12 Mar 2026
- Last updated
- 17 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT07531251
- Acronym / sponsor ID
- 4TAZPower / SPIBA-401
- Conditions
- Barth Syndrome
- Keywords
- BTHS, Ultra Rare X-Linked Mitochondrial Disorder, Genetic Defect in TAZ Gene
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- Stealth BioTherapeutics Inc.Industry (pharma, biotech, devices)
- Study start
- 2 Jul 2026 (actual)
- Primary completion
- 30 Sep 2029 (estimated)
- Study completion
- 30 Nov 2029 (estimated)
- First posted
- 15 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- 1:1 Randomization
| Arm | Type | Receives |
|---|---|---|
| Elamipretide | Active comparator | Drug: ElamipretideElamipretide - 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], |
| Placebo | Placebo comparator | Drug: PlaceboMatching 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 |
Who may qualify
- Ages
- 5 to 55 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (8 listed)
- 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.
- Agrees to adhere to the trial requirements for the length of the trial.
- Must have genetically confirmed Barth Syndrome (pathogenic variant in the TAZ gene)
- Male aged ≥ 5 years at time of the Screening Visit
- Left Ventricular Ejection fraction of ≥ 50% by 3-D Echocardiogram at the Screening Visit.
Key exclusion criteria (12 listed)
- Unable to perform the required functional tests or undergo echocardiography.
- 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.
- Patients with an implantable cardioverter defibrillator (ICD) and with a known occurrence of ICD discharge in the 3 months prior to the Screening Visit.
- Current placement on the waiting list for heart transplantation.
- Hospitalization for heart failure within 6 months prior to the Screening Visit.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ElamipretideAlso: elamipretide hydrochloridesub cutaneous injection | Drug | Elamipretide |
| Placebosub cutaneous injection | Drug | Placebo |
Primary outcome
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
7 secondary outcomes
Secondary Efficacy End Point 1
Time frame: 72 weeks
Secondary Efficacy End Point 2
Time frame: 72 weeks
Secondary Efficacy End Point 3
Time frame: 72 weeks
Secondary Efficacy End Point 4
Time frame: 72 weeks
Secondary Efficacy End Point 5
Time frame: 72 weeks
Secondary Efficacy End Point
Time frame: 72 weeks
Secondary Efficacy End Point 6
Time frame: 72 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Sep 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Lani Glennon contact
Rekha Sathyanarayana study director
Stealth BioTherapeutics Inc.
3 sites in 3 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Elamipretide in people with Barth Syndrome, run by Stealth BioTherapeutics Inc. at 3 sites in 3 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 17 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in United States, Canada, United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rekha Sathyanarayana (617-762-2579, rekha.sathyanarayana@stealthbt.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary Efficacy End Point (time frame: 72 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Sep 2026.