Elamipretide

Elamipretide is a genuinely mixed, still-unfolding story: a real FDA accelerated approval in September 2025 (as Forzinity) for ultra-rare Barth syndrome, based on a surrogate endpoint — sitting right alongside a real, completed Phase 3 failure in the more common primary mitochondrial myopathy, and an unresolved Phase 3 program in dry age-related macular degeneration. Unlike humanin, this compound has genuine human randomized trial data across several indications — it just hasn't produced a clean, broad win.

What it is, and its real 2025 approval

Elamipretide is a small, cell-permeable, mitochondria-targeted peptide developed by Stealth BioTherapeutics that binds cardiolipin on the inner mitochondrial membrane, intended to stabilize mitochondrial structure and function. FDA had issued a Complete Response Letter rejecting the original NDA in May 2025, recommending resubmission based on knee-extensor muscle strength as an intermediate clinical endpoint; after resubmission in July 2025, FDA granted accelerated approval to elamipretide HCl (brand name Forzinity) on 19 September 2025 for adult and pediatric patients weighing at least 30kg with Barth syndrome — an ultra-rare, X-linked mitochondrial disease affecting an estimated 150 people in the US — making it the first approved treatment for the condition.

A real completed Phase 3 failure, in a related disease

The Barth-syndrome approval sits alongside a real negative result elsewhere: the MMPOWER-3 Phase 3 trial (218 patients: 109 elamipretide, 109 placebo) tested elamipretide in the broader, more common condition of primary mitochondrial myopathy and did not meet either co-primary endpoint at week 24 — six-minute walk distance (-3.2m vs. placebo, p=0.69) or total fatigue score on the PMM Symptom Assessment (p=0.37). A prespecified subgroup — patients with disease-causing nuclear DNA (rather than mitochondrial DNA) mutations — showed an improvement in walk distance in post-hoc analysis, which is hypothesis-generating only, not confirmatory.

The dry AMD program: still unresolved

A separate elamipretide program targets geographic atrophy from dry age-related macular degeneration. The Phase 2 ReCLAIM-2 trial (48 weeks, daily 40mg subcutaneous) did not meet its primary endpoints (low-luminance visual acuity and geographic-atrophy area) but found a statistically significant slowing of ellipsoid-zone (photoreceptor-layer) degradation (p=0.0034) — a real, if secondary, signal. That endpoint became the regulatory-agreed primary endpoint for the ongoing Phase 3 program (ReNEW and ReGAIN trials), which as of this review had not yet reported results. Some peptide-development trackers list this program under the name "Ocuvia," though we could not confirm that name from a Stealth BioTherapeutics press release directly.

Why this is a genuinely mixed record

Elamipretide is a rare case on this site: a compound with real, completed, randomized human trials across three separate indications, producing one real (if narrow, surrogate-based) approval, one real completed failure, and one real unresolved program — all at once. That's a materially different, and more evidence-grounded, story than humanin's zero-human-trials picture, even though both get marketed in overlapping "mitochondrial peptide" circles.