BALA CYNWYD, Pennsylvania, April 30, 2026
Larimar Therapeutics, Inc. announced the publication of new cross-species research supporting the use of skin as a surrogate biomarker for frataxin (FXN) levels in tissues relevant to Friedreich’s ataxia (FA), a rare and progressive neurodegenerative disease. Published in a peer-reviewed scientific journal, the findings provide critical translational evidence that treatment with nomlabofusp significantly increases FXN levels across multiple tissues, with strong correlation observed between clinically relevant organs and accessible peripheral tissues such as skin and buccal cells. These results represent a major step forward in simplifying disease monitoring and accelerating clinical development pathways for FA therapies.
Cross-Species Evidence Strengthens Translational Validity
The study evaluated preclinical models including mice, rats, and non-human primates, consistently demonstrating that nomlabofusp restores FXN protein levels in key tissues affected by FA, including those central to neurological and cardiac function. Importantly, these increases were shown to closely correlate with FXN levels measured in peripheral tissues, particularly skin and buccal cells, which are significantly easier to access in clinical settings.
This cross-species consistency is critical because it confirms that peripheral biomarkers can reliably reflect therapeutic activity in target organs, addressing one of the biggest challenges in rare disease drug development—measuring treatment impact without invasive procedures.
Clinical Correlation Supports Surrogate Endpoint Strategy
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Beyond preclinical validation, the study also reported similar correlations in patients with Friedreich’s ataxia treated with nomlabofusp, reinforcing the clinical relevance of these findings. The ability to measure FXN levels in skin as a reasonably likely surrogate endpoint (RLSE) has significant regulatory implications.
This dataset has already been reviewed by the U.S. Food and Drug Administration (FDA) as part of Larimar’s strategy to pursue accelerated approval, a pathway designed to bring promising therapies to patients faster based on surrogate biomarkers. By demonstrating that skin FXN levels mirror changes in critical tissues, the company strengthens its case for using this non-invasive measurement to support efficacy claims in registrational trials.
Nomlabofusp Positioned as a Disease-Modifying Therapy
Nomlabofusp, Larimar’s lead investigational therapy, is designed to deliver frataxin directly into cells, addressing the underlying cause of FA rather than just managing symptoms. Friedreich’s ataxia is caused by a deficiency of FXN, leading to mitochondrial dysfunction, neurodegeneration, and progressive loss of mobility and cardiac complications.
Current treatment options are limited and largely supportive, making the development of a potential disease-modifying therapy highly significant. The newly published data not only validate the mechanism of action of nomlabofusp but also provide a practical and scalable method to monitor treatment response, which is essential for both clinical trials and future real-world use.
Accelerated Approval Pathway and Upcoming Milestones
Larimar Therapeutics is now leveraging these findings to support its Biologics License Application (BLA) submission planned for June 2026, marking a critical milestone in its development timeline. The use of a validated surrogate endpoint such as skin FXN levels could significantly reduce development timelines and regulatory uncertainty, enabling faster access to therapy for patients with FA. The consistency of results across species and in human studies adds robust scientific credibility to the program and aligns with regulatory expectations for surrogate endpoint validation.
Broader Impact on Rare Disease Drug Development
This advancement goes beyond a single therapy, highlighting a broader shift in how biomarkers are used in rare disease research. The ability to rely on non-invasive, reproducible, and clinically meaningful surrogate endpoints could transform development strategies across multiple conditions where direct tissue sampling is challenging or impractical. Larimar’s work demonstrates how integrating translational science with regulatory strategy can accelerate innovation while maintaining scientific rigor.
Overall, the findings position Larimar Therapeutics at the forefront of precision medicine in rare neurological diseases, with nomlabofusp emerging as a promising candidate to address a critical unmet need. By validating skin as a reliable surrogate for FXN measurement, the company has taken a decisive step toward streamlining clinical trials, enabling earlier intervention, and improving outcomes for patients with Friedreich’s ataxia.
Source: Larimar Therapeutics press release
