Rare disease · Phase 2 / Phase 3
TAZPOWER: controlled trial and open follow-up
What was tested?
Elamipretide versus placebo in a crossover study of people with genetically confirmed Barth syndrome, followed by open-label treatment. ↗
Registered primary question: Six-minute walking distance and total fatigue score during the controlled 12-week treatment periods. ↗
What the reviewed report found
Journal year 2021 · Article summary reviewed 2026-09-15
Neither primary endpoint was met in the randomized period. Walking distance and reported fatigue improved during the uncontrolled extension.↗
Keep in context: The controlled phase did not meet either primary endpoint. Later open-label improvements come from a smaller group without a concurrent placebo comparison. ↗↗
What a closer reading adds
Selected full-text sections checked 2026-09-20. These notes add context to the earlier article summary; they are not a complete risk-of-bias assessment.
One cohort, two different phases
Twelve participants completed both controlled treatment periods. Ten entered the open-label extension, and eight contributed measurements at extension week 36; two discontinued because of injection-site reactions. These are nested populations, not independent trials. Full text ↗ · Indexed abstract ↗
Sections: Patient characteristics; Outcomes and follow-up: part 1—placebo-controlled study; Outcomes and follow-up: part 2—open-label extension.
The extension changes the main question
The full text identifies walking distance and fatigue as primary outcomes of the controlled phase. Long-term safety and tolerability were primary in the extension; functional measures were secondary. Open-label changes cannot replace the negative controlled comparison. Full text ↗ · Indexed abstract ↗
Sections: Outcome measures; Outcomes and follow-up: part 1—placebo-controlled study; Outcomes and follow-up: part 2—open-label extension; Limitations.
Participants, design, limitations and sources
Registry snapshot
- Registry enrollment
- 12 · reported actual
- Registry status
- Completed
- Allocation and masking
- Randomized · Quadruple
- Design
- Crossover
- Eligible ages
- 12 Years; maximum not specified
- Registry results
- Posted in this snapshot
Registry source ↗ · Updated 2024-04-16; retrieved 2026-09-20. Registry enrollment is not necessarily the analyzed sample in a publication. Posted registry results and published article results are separate.
TAZPOWER: randomized and early extension results
- Design in the report
- A blinded placebo-controlled crossover trial was followed by an open-label extension.↗
- Participants in the report
- Twelve participants with Barth syndrome entered the randomized study; ten entered the extension and eight reached 36 weeks.↗
- Limitations
- The extension lacks a concurrent placebo group and has attrition. Its changes cannot be interpreted as another randomized treatment effect; the abstract does not provide a detailed harms assessment.↗
This reading covers the article abstract and record metadata. Read its preserved Human Evidence Review →
Trial identity checked in the full text on 2026-09-20: The methods identify this registered study explicitly; the identifier is not taken from a background citation or ethics approval. Identity source ↗
How the study identity and sources were checked
Study context checked 2026-09-20. Existing article summaries keep their original review dates. This is a selected study reading, not a complete literature or full-text appraisal.
Registry
A Trial to Evaluate Safety, Tolerability and Efficacy of Elamipretide in Subjects With Barth Syndrome ↗
Protocol identifier: SPIBA-201. Sponsor: Stealth BioTherapeutics Inc..
Retrieved 2026-09-20; SHA-256 57fc2c26917da4b47800315a18c68289b0a8597526429c919895070f5cfb1b20.
PMID 33077895
Exact trial identity is declared in the inspected full-text section. No matching reference is declared in this registry snapshot. These source labels do not establish that every result in a paper applies to this trial.
Identity metadata retrieved 2026-09-20. PubmedArticle[MedlineCitation/PMID=33077895] in the retained EFetch batch. SHA-256 0e6795be99af1c93f3a3e2726fc8a17152661ca29e8dead110bff36feb856127.
Scientific summary uses the original 2026-09-15 source snapshot: SHA-256 7be61a5476f72d7700d76f4e84d64de9269524a305e0f8591b3575519602e747.
Selected full text: PMC7935714
Retrieved 2026-09-20; SHA-256 ea8b01a5464860686aba02cae7e90c580dc554558f0b00b68f4745f33b106277. Section identifiers and hashes are included in the cited study data.