#United States #Needham #Stealth BioTherapeutics #Barth Syndrome #FDA Delay

Stealth BioTherapeutics Delays in FDA Review

Stealth BioTherapeutics Inc., a clinical-stage biotech firm focusing on innovative therapies for mitochondrial dysfunction diseases, has faced a delay in the FDA's action date regarding their new drug application (NDA) for elamipretide, aimed at treating Barth syndrome. This ultra-rare, life-threatening condition impacts under 150 individuals in the United States and fewer than 300 worldwide.

Key Announcement

On April 29, 2025, the company disclosed that the FDA would not adhere to the scheduled Prescription Drug User Fee Act (PDUFA) date for the NDA of elamipretide. According to Stealth's CEO, Reenie McCarthy, the FDA continues to thoroughly review the NDA and has initiated dialogue concerning post-marketing requirements. The firm anticipates further details about a revised action date soon. This information will assist them in facilitating expanded and emergency access to elamipretide while progressing towards potential FDA approval.

Timeline of Events

Stealth's NDA was first submitted to the FDA on January 29, 2024. It was formally accepted for standard review on March 29, 2024, with an initial PDUFA date slated for January 29, 2025. The review was then granted priority status on May 6, 2024. A significant moment came on October 10, 2024, when the Cardiovascular and Renal Drugs Advisory Committee (CRDAC) endorsed elamipretide’s effectiveness for Barth syndrome. However, a request from the FDA for additional analyses in late 2024 pushed the PDUFA date back to April 29, 2025.

Understanding Barth Syndrome

Barth syndrome is a genetic mitochondrial disorder characterized by various debilitating symptoms: exercise intolerance, muscle weakness, severe fatigue, heart failure, recurrent infections, and stunted growth. Tragically, the condition is linked to reduced life spans, with an alarming 85% of early deaths occurring before the age of five. The disease predominantly affects males, with estimates suggesting an occurrence of one in one million males globally or around 150 cases in the United States.

Currently, there are no approved treatments available for managing Barth syndrome, which underscores the critical need for effective new therapies like elamipretide. Stealth BioTherapeutics has made strides in providing access to elamipretide, with over 35 patients worldwide receiving expanded or emergency access to the drug, including critically ill young children.

The Future for Stealth BioTherapeutics

Stealth BioTherapeutics remains committed to its mission of developing advanced treatments for mitochondrial dysfunction diseases. Their lead candidate, elamipretide, is not only being evaluated for Barth syndrome but also for other conditions such as primary mitochondrial myopathy and dry age-related macular degeneration, where Phase 2 trials reported promising protective effects against photoreceptor loss.

The company is also exploring a second-generation medicine, bevemipretide (SBT-272), designed for dry age-related macular degeneration through a topical ophthalmic formulation. With an extensive pipeline of innovative compounds aimed at tackling rare neurological, cardiac, and myopathic diseases, Stealth BioTherapeutics is poised to make significant contributions to the field of biotechnology.

Conclusion

As the FDA deliberates on elamipretide, all eyes are on Stealth BioTherapeutics as they navigate this critical phase in drug development for Barth syndrome. There remains much uncertainty regarding the timeline of approvals and future studies, but with ongoing dialogue with the FDA, the hopes are high for both the company and the patients yearning for effective treatments for this rare condition.