By Fineline Cube 
The U.S. Food and Drug Administration (FDA) granted accelerated approval to Stealth BioTherapeutics’ Forzinity (elamipretide) injection, the first treatment approved for Barth syndrome in patients weighing at least 30 kg. Barth syndrome, a rare X‑linked mitochondrial disorder, predominantly affects males and often presents with severe infantile heart failure, leading to premature mortality. Adults who survive into adolescence frequently suffer chronic fatigue, impaired stamina, and exercise intolerance, profoundly diminishing quality of life.
How Forzinity Works
Forzinity targets the inner mitochondrial membrane, restoring mitochondrial ultrastructure and enhancing bioenergetic function. The accelerated approval hinged on a statistically significant improvement in knee extensor muscle strength—the pivotal muscle used to straighten the knee. The FDA judged this gain as “reasonably likely to predict” meaningful clinical benefits such as easier standing and increased walking distance.
Post‑Approval Commitments
Under the accelerated approval pathway, Stealth BioTherapeutics must conduct a post‑approval, randomized, double‑blind, placebo‑controlled trial to confirm that the observed muscle‐strength gains translate into real‑world benefits for Barth syndrome patients.
Market and Therapeutic Impact
- First‑in‑class: Forzinity represents the inaugural pharmacologic option for a disease with no prior approved therapies.
- Patient‑Centric: By improving mitochondrial function, the drug targets the root of the metabolic defect, potentially altering disease trajectory.
- Regulatory Milestone: The FDA’s accelerated pathway underscores the unmet medical need and the promise of early patient access balanced with rigorous confirmatory studies.-Fineline Info & Tech