SS-31
Elamipretide (Forzinity) — Barth accelerated approval and MMPOWER-3 miss both stay in view.
Editorial review:Evidence snapshot
This drawer marks papers. It is not a plan, a dose, or a source. A paper is a bounded report. It is not a protocol. Grades name the object. They are not a safety rating.
Identity lock. SS-31 (also MTP-131, Bendavia; INN elamipretide) is a mitochondria-targeted tetrapeptide that binds cardiolipin on the inner mitochondrial membrane. PubChem CID 11764719; formula C32H49N9O5 / MW 639.8; CAS 736992-21-5. Clinical status (same breath): in September 2025, elamipretide (Forzinity) received US accelerated approval to improve muscle strength in Barth syndrome (adult and pediatric patients meeting labeled weight criteria) — first disease-specific Barth treatment in that approval narrative (PMID 41335372). MMPOWER-3 Phase 3 in primary mitochondrial myopathy did not meet co-primary efficacy endpoints (6MWT / fatigue) (PMID 37268435). Unlabeled “SS-31 vials” are not the Forzinity labeled object. Other programs (e.g. dry AMD, broader mitochondrial myopathy) remain investigational. This drawer marks papers. It is not use advice.
Bottom line
Barth syndrome has a labeled accelerated-approval object plus TAZPOWER open-label extension and natural-history comparison work. Primary mitochondrial myopathy Phase 3 (MMPOWER-3) was negative on co-primary endpoints. Mechanism and cardiolipin-targeting reviews explain the class but do not invent extra indications. Preclinical neuroprotection / organ-injury papers are not human grades. Keep the Barth approval and the PMM miss visible together.
Papers
Labeled / late clinical — Barth syndrome
PMID 41335372 — Shirley 2026
Tested: regulatory milestone review — elamipretide (Forzinity) first approval / accelerated approval narrative for Barth syndrome muscle-strength indication.
Does not show: approval for primary mitochondrial myopathy, cosmetic “mito support,” or every investigational indication under development.
PMID 38602181 — Thompson 2024
Tested: long-term efficacy and safety of elamipretide in Barth syndrome during the 168-week open-label extension of TAZPOWER.
Does not show: a new double-blind placebo-controlled Phase 3 replacement by itself, or MMPOWER-3 success.
PMID 36056411 — Hornby 2022
Tested: natural-history comparison study supporting efficacy assessment of elamipretide in Barth syndrome relative to historical controls (small treated cohort).
Does not show: a large randomized PMM win, or broad cardiomyopathy approval beyond the Barth program framing.
PMID 34623544 — Sabbah 2022
Tested: narrative on elamipretide for Barth syndrome cardiomyopathy (gradual rebuilding of mitochondrial bioenergetics framing).
Does not show: a new primary RCT; secondary commentary.
Primary mitochondrial myopathy — Phase 3 miss
PMID 37268435 — Karaa 2023
Tested: MMPOWER-3 — pivotal Phase 3 randomized, double-blind, placebo-controlled trial of subcutaneous elamipretide in genetically confirmed primary mitochondrial myopathy (6MWT and fatigue co-primaries).
Does not show: efficacy on those co-primaries (Class I evidence of no improvement at 24 weeks vs placebo); tolerability is not an efficacy win.
PMID 39574155 — Karaa 2024
Tested: genotype-specific post hoc analysis of elamipretide in MMPOWER-3 PMM participants.
Does not show: that post hoc genotype signals reverse the failed primary analysis into a labeled PMM indication.
Mechanism / class reviews
PMID 24117165 — Szeto 2014
Tested: review of first-in-class cardiolipin-protective SS peptides as agents to restore mitochondrial bioenergetics.
Does not show: a completed pivotal approval package by itself.
PMID 35037146 — Obi 2022
Tested: review targeting mitochondrial dysfunction with elamipretide.
Does not show: new primary trial data; secondary synthesis.
PMID 39940712 — Tung 2025
Tested: structure / mechanism / therapeutic-potential review of elamipretide.
Does not show: a new Phase 3 result.
PMID 32554501 — Chavez 2020
Tested: mitochondrial protein-interaction landscape of SS-31 (proteomics / target engagement science).
Does not show: human clinical efficacy for any indication.
What is not established
That accelerated Barth approval equals approval for PMM, aging, or general “mitochondrial optimization.” That MMPOWER-3 failed primaries can be ignored. Interchangeability of unlabeled “SS-31 vials” with Forzinity trial/approved material. Preclinical organ-injury models as human treatment claims. This drawer does not provide use advice, schedules, or sourcing.
Selected sources
41335372 38602181 36056411 34623544 37268435 39574155 24117165 35037146 39940712 32554501
Reported experiences
Reported topics are not established benefits.Risks and unknowns
Compare experiences with care.
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