MOLECULAR INFORMATION
Molecular information
- Length
- 6 amino acids
- Type
- Cell-permeable tetrapeptide · cardiolipin-binding · mitochondrial-targeted
Amino acid sequence
D-Arg-Dmt-Lys-Phe-NH₂ SS-31 (elamipretide / MTP-131) is a cell-permeable tetrapeptide developed by Stealth BioTherapeutics. Selectively binds cardiolipin in the inner mitochondrial membrane, stabilising the electron transport chain. The most clinically-advanced mitochondrial-targeted peptide.
Status
- Phase 3 (PROGRESS / SPIMM) ongoing for primary mitochondrial myopathy
- Phase 2 / 3 work in Barth syndrome and dry AMD
- FDA Complete Response Letter in primary mitochondrial myopathy (2024); resubmission pending additional data
Why we grade it B
Multiple Phase 2 trials with consistent functional-endpoint signal in mitochondrial diseases. Mechanism is well-characterised and supported by non-redundant cell-biology data. Promotion to A waits on a clean Phase 3 read-out and regulatory authorisation.