SS-31 (Elamipretide)

Also known as: Elamipretide, MTP-131, Bendavia, mitochondria-targeting tetrapeptide

Wellness

In plain English

SS-31 (also called elamipretide) is a peptide designed to protect the mitochondria, the energy-producing parts of cells, by stabilizing a key membrane component. It has been studied as an investigational drug for mitochondrial diseases and heart failure. Results so far are mixed—several major trials did not meet their main goals—so it remains investigational and is not FDA-approved.

The science

SS-31/elamipretide is a cell-permeable tetrapeptide that concentrates in the inner mitochondrial membrane and binds cardiolipin, stabilizing cristae structure and improving electron-transport-chain efficiency and ATP production while reducing reactive oxygen species. Despite strong rationale, the pivotal phase 3 MMPOWER-3 trial in primary mitochondrial myopathy (n=218) did not meet its primary endpoints (6-minute walk distance, fatigue), and a phase 2 heart-failure trial (PROGRESS-HF) was also negative; some benefit was suggested in Barth syndrome. It is investigational, not FDA-approved, and human efficacy remains unproven for most indications despite good tolerability.

References

• Karaa A et al., Neurology 2023 (MMPOWER-3)