A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome, a genetic disorder of mitochondrial cardiolipin metabolism.

What was studied

This crossover trial and extension tested elamipretide for walking capacity, fatigue, strength, symptoms and cardiac measures in genetically confirmed Barth syndrome.

Who / model studied

Twelve male participants with genetically confirmed Barth syndrome entered the randomized crossover; ten entered the extension and eight reached week 36.

Studied dose & schedule

Participants received 40 mg subcutaneous elamipretide daily or placebo for 12 weeks, crossed over after a 4-week washout, then could continue open-label treatment.

What the study found

Neither primary endpoint was met in the controlled crossover. In the open-label extension at week 36, walk distance improved 95.9 m and symptom score improved 2.1 points from baseline.

Limitations & context

The extension involved only eight completers and lacked a concurrent placebo group, so learning and placebo effects cannot be excluded. Injection-site reactions predominated.

Read summary source ↗ · Prepared 10/6/2026 · AI-assisted, source-based summary