Elamipretide now has an FDA-approved finished product for a narrow Barth syndrome indication, but the approval rests on an unusual rare-disease dataset. The randomized portion included 12 participants and did not meet its two primary endpoints.
What the record shows
- All 12 randomized participants were male, aged 12 to 35 years, at one US site.
- The randomized trial did not show superiority on its 6-minute-walk or fatigue primary endpoints.
- FDA granted accelerated approval based on knee-extensor strength observed during longer open-label follow-up and required a confirmatory trial.
Study record
The crossover study compared 12-week periods of elamipretide and placebo, separated by washout. Ten participants entered the open-label extension and eight were followed through week 168.
Results in context
FDA reports a median baseline knee-extensor strength of 124 newtons. Median changes at week 12 were −5 newtons on placebo and +4 on elamipretide; larger descriptive changes appeared during the open-label extension, including +63 newtons among eight participants at week 168.
Open-label change is vulnerable to time effects, expectation, selective continuation and the absence of a concurrent control. FDA therefore required post-approval confirmation that the strength change translates into patient benefit.
What this study cannot answer
The dataset is extremely small and cannot support subgroup analysis.
The approval applies to Forzinity for patients with Barth syndrome weighing at least 30 kg—not to generic “SS-31” materials or other uses.
Sources & editorial method
The editorial workflow starts with linked peer-reviewed papers, trial registries or regulatory records; extracts the population or model, endpoints, numerical results and limitations; and separates the studied intervention from catalog material. AI-assisted drafting was used to structure the first version. Claims, figures, evidence labels and limitations were checked against the linked records in the site editorial workflow. This is not independent peer review.
3 linked records are listed in the references below. Read the editorial and AI-assistance policy.
How to interpret this article
Source-checked on 2026-08-28. Null findings and study limitations are retained. This is not independent peer review, medical advice, a customer case, or validation of a catalog lot.
Research-use boundary: Catalog materials discussed on this website are for laboratory research, development and manufacturing use only, not for human or veterinary use. This content is not medical advice and does not provide administration instructions.
Primary records and authoritative sources
- FDA Drug Trials Snapshot: ForzinityU.S. FDA. Approval date September 19, 2025; SPIBA-201 population and endpoint record.
- Elamipretide phase 2/3 trial in Barth syndromeReid Thompson W, et al. Genetics in Medicine. 2021. PMID 33077895.
- FDA accelerated approval announcement for ForzinityApproval scope and confirmatory requirement.
Continue with structured records
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