What it is
SS-31, developed under the name elamipretide, is a synthetic aromatic-cationic tetrapeptide that concentrates in the inner mitochondrial membrane. It appears in mitochondrial medicine research, including programmes in primary mitochondrial myopathy, Barth syndrome and retinal disease.
How it works
Elamipretide binds cardiolipin in the inner mitochondrial membrane. It is thought to stabilise cristae architecture and improve electron transport efficiency, which is proposed to lower reactive oxygen species production.
Regulatory status
- Cosmetic ingredient
- Research compound
- In clinical trials
- Approved medicine
Approved as a medicine by the FDA or the EMA for at least one indication. Approval covers the named indication and formulation only.
What published research is studying
- Exercise capacity and fatigue in genetically confirmed primary mitochondrial myopathy (Phase 2 and Phase 3 trials)
- Walking distance and cardiac volumes in Barth syndrome (Phase 2/3 trial and open-label extension)
- Geographic atrophy growth and ellipsoid zone preservation in age-related macular degeneration (Phase 1 and Phase 2)
- Monolysocardiolipin to cardiolipin ratio as a mechanistic biomarker
Key findings
In MMPOWER-3, a Phase 3 trial in 218 adults with primary mitochondrial myopathy, elamipretide did not improve 6-minute walk distance or total fatigue at 24 weeks.
Karaa A et al., Neurology 2023 (NCT03323749)In MMPOWER-2, a 30-participant randomized crossover trial, the 19.8 m difference in 6-minute walk distance missed significance, while reported fatigue improved (p = 0.0006).
Karaa A et al., J Cachexia Sarcopenia Muscle 2020In the 168-week open-label extension of TAZPOWER in Barth syndrome, 6-minute walk distance improved by a cumulative 96.1 m at week 168 (p = 0.003).
Thompson WR et al., Genet Med 2024 (NCT03098797)
What the studies measured
Study durations
- MMPOWER-3: 24 weeks of randomized double-blind treatment in 218 participants (NCT03323749).
- MMPOWER-2 crossover: 4 weeks per period, separated by a 4-week washout (Karaa 2020).
- TAZPOWER: a 28-week randomized period followed by a 168-week open-label extension (NCT03098797).
Endpoints
- Distance walked on the 6-minute walk test
- Primary Mitochondrial Myopathy Symptom Assessment total fatigue score
- Neuro-QoL Fatigue Short Form T score
- Three-dimensional left ventricular stroke and end-diastolic volumes
- Monolysocardiolipin to cardiolipin ratio
How strong is the evidence?
Elamipretide has been through randomized Phase 2 and Phase 3 trials in rare mitochondrial disease, but the pivotal Phase 3 trial missed both of its primary endpoints.
Common questions
Is SS-31 an approved medicine?
Approved medicine. Approved as a medicine by the FDA or the EMA for at least one indication. Approval covers the named indication and formulation only.
How much human research is there on SS-31?
Elamipretide has been through randomized Phase 2 and Phase 3 trials in rare mitochondrial disease, but the pivotal Phase 3 trial missed both of its primary endpoints.
Does UU supply SS-31?
Yes, as premium-grade research material for laboratory use. Every batch is tested by an independent lab and the certificate of analysis is published.