At a glance
| Product | Forzinity |
|---|---|
| Former codes | SS-31; MTP-131 |
| Target | Mitochondrial cardiolipin |
| FDA population | Barth syndrome, body weight ≥30 kg |
| Approval pathway | Accelerated approval |
Overview
Forzinity contains elamipretide, previously known as SS-31 or MTP-131. Barth syndrome is a rare mitochondrial disorder linked to abnormal cardiolipin biology. The FDA granted accelerated approval based on improvement in knee-extensor muscle strength, an intermediate clinical endpoint. The evidence history requires nuance: the small randomized study did not show superiority on its primary walking-distance and fatigue endpoints, while longer open-label follow-up supported the strength finding used for approval. This profile therefore updates older research-only classifications without overstating the certainty or breadth of the clinical benefit.
How it works
Elamipretide localizes to the inner mitochondrial membrane and binds cardiolipin, a lipid important to mitochondrial structure and function. The approved label describes improvement in mitochondrial morphology and function. This mechanism is relevant to Barth syndrome’s biology, but a mitochondrial target is not evidence that treatment improves every condition associated with fatigue, aging or reduced energy production. Clinical indication and molecular mechanism must be distinguished.
The approved indication
Forzinity is indicated to improve muscle strength in adults and children with Barth syndrome who weigh at least thirty kilograms. It is not a general approval for primary mitochondrial myopathy, ordinary fatigue or longevity enhancement.
Supporting sources [1]
Why the evidence is conditional
The randomized trial enrolled twelve participants and did not meet its primary walking-distance or fatigue endpoints. Muscle-strength improvement emerged during the open-label extension. The label explicitly bases accelerated approval on the intermediate strength endpoint and requires confirmatory benefit assessment.
Supporting sources [1]
What longer follow-up adds
The published extension described sustained changes in functional and cardiac assessments among a very small number of participants. Without a concurrent blinded control group, these findings are informative but more vulnerable to bias than a successful randomized comparison.
Supporting sources [2]
Important precautions
Injection-site reactions are common, and serious hypersensitivity can occur. The formulation contains benzyl alcohol and is not approved for neonates. Kidney impairment affects the labeled treatment considerations; the actual prescription product’s information governs use.
Supporting sources [1]
Does approval validate SS-31 sold online?
No. Approval applies to the regulated Forzinity product and its defined indication. A research product using the SS-31 name does not inherit the approved manufacturing standard or demonstrate equivalent composition, exposure or clinical benefit.
Supporting sources [1]
Reading this profile
Jurisdiction: United States — FDA accelerated approval in September 2025 for Barth syndrome patients weighing at least 30 kg; confirmatory benefit requirement.. Molecular class: Mitochondrial cardiolipin-binding tetrapeptide.
This profile was written with AI-assisted research and checked against the linked sources. It has not been represented as a clinician’s review. Evidence summaries describe the cited studies and products; they do not establish that a separately purchased preparation is equivalent.
Sources & references
Follow the original material. Product labels define specific formulations and uses; trial registration describes a study and does not by itself establish benefit.
- DailyMed: Forzinity prescribing information ↗Regulatory source · Checked 2026-10-27
- Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. ↗Original research · Checked 2026-10-27