NEEDHAM, Mass., October 9, 2025 — Stealth BioTherapeutics Inc. has announced the launch of Mito Assist™, a comprehensive patient support program to facilitate access to FORZINITY™ (elamipretide) injection, the first and only FDA-approved treatment for Barth syndrome. In tandem, Stealth revealed a strategic partnership with AnovoRx Specialty Pharmacy, which will serve as the exclusive U.S. commercial distributor for the therapy. This milestone highlights Stealth’s expanding commercial infrastructure following FORZINITY’s accelerated approval by the U.S. Food and Drug Administration (FDA) on September 19, 2025.
Science Significance
The launch of Mito Assist™ and the FORZINITY™ access framework reflects a major advancement in mitochondrial medicine—a field focused on correcting defects in the body’s cellular energy engines. FORZINITY™ (elamipretide), a mitochondrial cardiolipin binder, represents a new class of therapies designed to stabilize mitochondrial structure and improve muscle function in patients suffering from Barth syndrome, an ultra-rare, life-threatening genetic disease. By targeting mitochondrial dysfunction, FORZINITY™ opens the door to a new generation of mitochondria-targeted therapeutics that may extend to other diseases such as primary mitochondrial myopathy and age-related macular degeneration, both of which Stealth is exploring in clinical programs. This approval establishes a scientific precedent, marking the first-ever FDA clearance for a mitochondria-targeted drug, which could significantly expand research interest in mitochondrial biology and rare disease therapeutics.
Regulatory Significance
Regulatorily, FORZINITY™ achieved accelerated approval based on improvement in knee extensor muscle strength, an intermediate endpoint validated as clinically meaningful for Barth syndrome. This decision underscores FDA’s flexibility in rare disease regulation, enabling earlier access while requiring confirmatory studies to verify long-term benefit. Stealth’s post-approval obligations include confirmatory clinical trials to substantiate efficacy and safety data under real-world conditions, which will determine the therapy’s continued approval. Through this framework, the FDA has reaffirmed its ongoing commitment to facilitating rapid access to therapies for ultra-rare diseases, where traditional large-scale clinical trials are often infeasible.
Business Significance
Advertisement
Commercially, this announcement marks Stealth’s transition from a late-stage biotech to a fully operational commercial biopharmaceutical company. Partnering with AnovoRx Specialty Pharmacy strengthens Stealth’s ability to deliver personalized, high-touch support to patients and healthcare providers. The partnership will streamline product distribution, insurance navigation, and at-home injection support, providing a unified structure for rare disease patient management. Stealth anticipates commercial availability of FORZINITY™ by December 2025, pending final logistics and payer activation. This moves signals Stealth’s readiness to compete in the ultra-rare genetic disease market, a high value but specialized sector of biopharma. The infrastructure and experience gained through FORZINITY’s rollout will also benefit future launches in Stealth’s pipeline, including bevemipretide (SBT-272), currently in development for ophthalmic and neurological indications.
Patients’ Significance
For patients and families affected by Barth syndrome, this program represents an unprecedented step forward. Prior to FORZINITY™, there were no FDA-approved treatments for this debilitating condition characterized by muscle weakness, heart failure, infections, and growth delays, often leading to early mortality. Mito Assist™ provides not just medication access but comprehensive support—insurance guidance, co-pay assistance, patient assistance programs for underinsured individuals, and home injection training. Importantly, patients transitioning from Stealth’s Expanded Access Program will receive direct coordination through AnovoRx to ensure a seamless shift to commercial therapy. This holistic approach demonstrates Stealth’s long-term commitment to the Barth syndrome community, which it has supported through more than a decade of research collaborations, patient advocacy, and clinical engagement.
Policy Significance
From a policy perspective, the FORZINITY™ approval and subsequent access initiatives highlight the evolving FDA strategy for rare disease drug development—balancing accelerated pathways with post-market verification requirements. Programs like Mito Assist™ embody the patient-centric access models now favored by both regulators and payers in the rare disease space. They serve as a case study in how industry, regulators, and patient organizations can collaborate to close the access gap for ultra-rare disorders that affect fewer than 200 patients in the U.S. Additionally, Stealth’s launch of a dedicated patient support infrastructure aligns with emerging U.S. healthcare policy priorities around equitable access, transparency, and affordability for orphan drugs.
Transaction Highlights
Stealth BioTherapeutics announced the official launch of its Mito Assist™ Patient Support Program in conjunction with a strategic commercial distribution partnership with AnovoRx Specialty Pharmacy. Through this collaboration, AnovoRx will serve as the exclusive distributor of FORZINITY™ (elamipretide) in the United States, supporting both healthcare providers and patients in navigating access, insurance coverage, and treatment logistics. The Mito Assist™ program is designed to offer personalized support services, including co-pay assistance for commercially insured patients, financial aid for underinsured or uninsured individuals, and training for at-home subcutaneous administration.
As part of the rollout, patients currently participating in Stealth’s Expanded Access Program who meet the 30 kg weight requirement will be transitioned seamlessly to commercial therapy with direct coordination through AnovoRx case managers. Stealth expects FORZINITY™ to be commercially available by December 2025, pending final payer readiness and distribution logistics. The company’s long-term commitment to patient access and continuity of care underscores its broader mission to bring mitochondrial-targeted therapies to underserved patient populations.
Source: Stealth BioTherapeutics Inc. Press Release
