FDA Grants Orphan Drug Designation to Elamipretide for Bath Syndrome

Today, Stealth BioTherapeutics announced that the US Food and Drug Administration (FDA) granted orphan drug designation to its investigational drug candidate elamipretide, intended for the treatment of patients with Barth syndrome.

Barth syndrome is genetic condition that occurs almost exclusively in males. It is characterized by a weakened and enlarged heart, recurrent infections due to small numbers of white blood cells, weakness in muscles used for movement, and short stature.³

Elamipretide is a mitochondrial protective agent that improves cell viability and organ function across several disease states, such as cardiovascular, renal, ophthalmic, metabolic and skeletal muscle disorders. Elamipretide appears to target and protect dysfunctional mitochondria—without affecting healthy mitochondria and cells—via a novel mechanism that improves electron transport chain (ETC) deficiencies in disease.⁴

Reenie McCarthy, Stealth's chief executive officer, explained the significance of the company’s drug. "There are currently no FDA-approved therapies for patients with Barth syndrome, a debilitating condition characterized by heart and skeletal muscle weakness. We believe elamipretide represents a promising, novel approach with the potential to offer hope for patients with Barth syndrome, and we are very pleased to have received Orphan Drug Designation for this indication."¹

In March 2018, completion of the TAZPOWER Phase 2/3 crossover study evaluating the effects of daily treatment of elamipretide was announced and followed by an open-label treatment extension. The crossover study included 12 male participants aged 12 and older with genetically confirmed Barth syndrome.²

The primary endpoints included change in distance walked during the 6-minute walk test, change in total fatigue as measured by a potent-reported outcome measure, and the Barth Syndrome Symptom Assessment. The crossover study was divided into 2 study arms: participants in the experimental arm were administered 40 mg of elamipretide via injection daily for 12 weeks and then a placebo for the sequential 12 weeks. The placebo arm received the same treatment in reverse order.

Data from the crossover trial is expected to be announced later this year.

The FDA granted Fast Track designation for elamipretide for the treatment of Barth syndrome in November 2017.

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References:

1. Stealth BioTherapeutics Granted Orphan Drug Designation for Elamipretide for Treatment of Barth Syndrome. PR Newswire. 9, Apr. 2018.
2. A Trial to Evaluate Safety, Tolerability and Efficacy of Elamipretide in Subjects With Barth Syndrome (TAZPOWER). Clinicaltrials.gov. Accessed 9, Apr. 2018.
3. Barth syndrome. ghr.nlm.nih.org https://ghr.nlm.nih.gov/condition/barth-syndrome. Accessed 9, Apr. 2018.
4. Bendavia. mitoaction.org. http://www.mitoaction.org/bendavia. Accessed 9, Apr. 2018.