#United States #Needham #Stealth BioTherapeutics #Barth Syndrome #Elamipretide

Stealth BioTherapeutics Resubmits NDA for Elamipretide

In a significant development, Stealth BioTherapeutics, an innovative biotechnology firm focused on mitochondrial-related diseases, has announced the resubmission of its New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for elamipretide. This drug is aimed at treating Barth syndrome, which is a rare genetic disorder predominantly affecting males and characterized by severe health complications such as exercise intolerance, muscle weakness, and heart failure.

Background of the Submission

Earlier in May 2025, the FDA provided a complete response (CR) to Stealth's initial NDA, suggesting that certain issues needed addressing before moving forward. The resubmission includes a minor update on safety, confirmation that previously noted manufacturing deficiencies have been resolved, and additional post-marketing commitments. Notably, it does not introduce new clinical efficacy data; the emphasis remains on previously established findings.

CEO Reenie McCarthy expressed gratitude for the FDA's acknowledgment of Barth syndrome's severity and the pressing need for effective therapies. The company is optimistic that all prior concerns raised by the FDA have been effectively addressed, setting the stage for a potential approval.

The Clinical Evidence

Elamipretide's efficacy was showcased in the TAZPOWER Phase 2 open-label clinical trial, where participants exhibited a remarkable improvement of over 45% in knee extensor muscle strength. This specific metric is important as it correlates with patient mobility, represented in the six-minute walk test, recognized by the FDA as a significant measure of clinical benefit. Such data underlie the importance of fast-tracking approval for therapies targeted at rare diseases like Barth syndrome.

Regulatory Progress

As of July 2025, the FDA confirmed that the manufacturing facility in question was compliant with Current Good Manufacturing Practices (CGMP), leaving no outstanding corrective actions required. This compliance was pivotal for the NDA resubmission since it assured the FDA that Stealth had taken immediate and effective measures to overcome earlier shortcomings identified in previous inspections.

The FDA classifies resubmissions as Class 1 or Class 2; the former indicates a rapid two-month review period, while the latter could extend up to six months. While there are indications that this resubmission might likely be classified as Class 2, Stealth has requested a Class 1 review due to the resolved manufacturing issues, indicating that no new inspections should be necessary.

The Urgency of Approval

If approved, elamipretide will become the first therapy authorized to treat Barth syndrome, a condition that historically lacks adequate treatment options. With a prevalence rate estimated at one in one million males worldwide, the urgent need for advancement in treatment options is underscored by the reality that many affected individuals face life-threatening complications or reduced life expectancy. The potential of elamipretide is further illustrated by its ongoing development for other mitochondrial dysfunction disorders.

Barth syndrome is not only an ultra-rare genetic disorder but also one that necessitates swift medical action. Stealth BioTherapeutics hopes that the FDA will prioritize this review, reflecting its commitment to addressing the unmet medical needs of a vulnerable patient population.

Company Overview

Stealth BioTherapeutics is at the forefront of developing therapies intended to address mitochondrial dysfunction, leveraging its innovative technologies to create treatment options for rare genetic disorders. Its work exemplifies the intense focus required to bring viable solutions to market, not just for Barth syndrome but for a broader array of conditions linked to mitochondrial energy production. The company is also pursuing additional avenues of research emphasizing the critical significance of mitochondrial health.

Visit Stealth BioTherapeutics for more detailed information regarding their initiatives and ongoing drug development programs.