Stealth Bio doubles as it gains Rare Pediatric Disease designation for elamipretide

US biotech Stealth BioTherapeutics (Nasdaq: MITO) saw its shares skyrocket 108.4% to $3.96 in morning trading on Tuesday, after it revealed that the US Food and Drug Administration has granted Rare Pediatric Disease (RPD) designation for elamipretide for the treatment of Barth syndrome, an ultra-rare genetic condition. The stock closed the day up 58% at $3.07.

Under the FDA's RPD designation program, the FDA may grant a priority review voucher to a sponsor who receives approval for a rare pediatric disease, a serious and life-threatening disease that primarily affects individuals aged from birth to 18 years and fewer than 200,000 people in the USA. On FDA approval of elamipretide for Barth, Stealth is eligible for a voucher that can be used to obtain priority review for a subsequent human drug application upon meeting relevant statutory requirements associated with the RPD program, or the voucher can be sold on.

"This designation for elamipretide underscores our alignment with the FDA around the significant and urgent unmet medical need for Barth patients," said Reenie McCarthy, chief executive of Stealth. "We hope to improve the healthspan of Barth patients, for whom cardiomyopathy, exercise intolerance and debilitating fatigue limit life expectancy and impair quality of life. We are also expanding our development efforts to consider trials in patients suffering from overlapping metabolic cardiomyopathies in diseases such as Duchenne and Becker muscular dystrophies, and Friedreich's ataxia," he added.