A Study of Elamipretide in Participants With Barth Syndrome (TAZPOWER) — VialBase Research

Trial Summary

TAZPOWER was a pivotal trial of elamipretide in Barth syndrome, a rare X-linked genetic disorder caused by mutations in the tafazzin gene, leading to abnormal cardiolipin remodeling and mitochondrial dysfunction. Barth syndrome causes cardiomyopathy, skeletal myopathy, neutropenia, and growth retardation. This represents the most biologically targeted application of elamipretide, since the disease mechanism (cardiolipin deficiency) directly matches the drug’s mechanism (cardiolipin stabilization).

Design

• Type: Crossover and open-label extension
• Population: 12 patients with genetically confirmed Barth syndrome
• Arms: Elamipretide 40 mg SC daily (crossover design with placebo)
• Duration: 12-week double-blind crossover + long-term open-label extension
• Key measures: 6MWT, BSSA symptom score, cardiac function (echocardiography), strength testing

Key Outcomes

• Improvements in 6MWT distance and BSSA symptom scores
• Improved cardiac stroke volume
• Positive long-term open-label extension data showing sustained benefits
• FDA granted Rare Pediatric Disease designation
• Despite promising data, the NDA path has been complex due to the ultra-small patient population
• Elamipretide received FDA approval for Barth syndrome in 2023 under the brand name ELAMPRET (conditional)

Significance for Peptide Research

TAZPOWER validates the mitochondria-targeting peptide concept in a disease with a precise biological match. The challenge of developing drugs for ultra-rare diseases (only ~200 known Barth patients worldwide) is significant, but the biological proof-of-concept is strong. This trial supports the broader hypothesis that mitochondria-targeting peptides can treat diseases of mitochondrial dysfunction when patient selection is precise.

See Also

• Related compound: SS-31