• Late-Breaking selection at the 31st Annual World Muscle Society Congress — a designation reserved for findings the program committee determines to be of immediate importance to the field
• Presentation expected to provide the first clinical evidence that a small activating RNA (saRNA) can upregulate an endogenous target protein in patients with a monogenic disease
• Utrophin upregulation is a mutation-independent approach with theoretical relevance across all DMD genotypes
• To be presented orally by Principal Investigator Professor Yi Dai, MD, PhD, Peking Union Medical College Hospital

NANTONG, China, Sept. 15, 2026 /PRNewswire/ -- Ractigen Therapeutics, a clinical-stage biotechnology company pioneering RNA activation (RNAa) therapeutics, today announced that first-in-human findings from its RAG-18 program in Duchenne muscular dystrophy (DMD) have been accepted for a Late-Breaking Presentation at the 31st Annual Congress of the World Muscle Society (WMS 2026), taking place 29th September-3rd October in Hiroshima, Japan.

For more than twenty years, the neuromuscular field has recognized utrophin — a naturally occurring structural relative of dystrophin — as one of the most compelling therapeutic ideas in DMD. Because utrophin can substitute for dystrophin at the muscle membrane regardless of which DMD mutation a patient carries, sufficiently increasing it would represent a mutation-independent approach relevant to the entire patient population. The obstacle has never been the biology. It has been the absence of a technology capable of turning a human gene up, on demand, in muscle.

That is the question the WMS presentation will address.

The presentation, titled "First-in-human evidence of RNA activation-mediated sarcolemmal utrophin upregulation in Duchenne muscular dystrophy," will be delivered orally by the study's Principal Investigator, Professor Yi Dai, MD, PhD, Department of Neurology, Peking Union Medical College Hospital (PUMCH), Chinese Academy of Medical Sciences. It will report available Cohort 1 findings from the ongoing open-label, dose-escalation trial (NCT07282652) in ambulatory boys with genetically confirmed DMD, spanning safety and tolerability, paired pre- and post-treatment muscle biopsies with quantitative immunofluorescence of sarcolemmal utrophin, muscle histopathology, serum creatine kinase, quantitative muscle MRI, spirometry, and motor function assessments.

Professor Yi Dai, MD, PhD, Principal Investigator, commented:

"Duchenne muscular dystrophy remains a devastating condition with profound unmet medical needs, particularly for therapies that can benefit all patients independent of their specific mutation. Utrophin upregulation has long represented a compelling biological approach, but achieving robust sarcolemmal target engagement in patients has been a historical challenge. We are encouraged by the concordant molecular, tissue-level, and exploratory functional signals observed in this first cohort and look forward to sharing these important findings with the global neuromuscular community at WMS."

Long-Cheng Li, MD, Founder, Chairman and Chief Executive Officer of Ractigen Therapeutics, added:

"This late-breaking presentation at WMS marks a defining inflection point for Ractigen and the entire field of RNA medicine. For years, RNA activation was considered an exciting biological concept; today, we have demonstrated that saRNA can reliably activate target gene expression in human skeletal muscle to rescue cellular integrity. RAG-18 has the potential to fundamentally redefine how we treat Duchenne muscular dystrophy, and we look forward to sharing the full depth of this remarkable clinical dataset with investigators, industry peers, and patient advocates worldwide."

• Title: First-in-human evidence of RNA activation-mediated sarcolemmal utrophin upregulation in Duchenne muscular dystrophy
• Abstract No.: 02LBO
• Session: Late-Breaking Oral Presentation
• Presenter: Professor Yi Dai, MD, PhD (Peking Union Medical College Hospital)
• Date & Time: Saturday, October 3, 2026, 12:00 PM – 12:15 PM (JST, UTC+9)
• Location: Phoenix Hall, International Congress Center Hiroshima (ICCH), Hiroshima, Japan

In compliance with WMS congress embargo regulations, detailed quantitative datasets, high-resolution immunofluorescence imaging, and comprehensive clinical outcomes will be unveiled during the official oral presentation.

RAG-18 is an investigational agent. It has not been approved by any regulatory authority, and its safety and efficacy have not been established.

About Duchenne Muscular Dystrophy (DMD)

DMD is a rare, severe, X-linked progressive neuromuscular disorder caused by mutations in the DMD gene that result in deficiency or absence of dystrophin, a protein essential to protecting muscle fibers from contraction-induced injury. Affected boys experience progressive muscle degeneration, loss of ambulation, respiratory insufficiency and cardiomyopathy. Utrophin is a structural and functional homolog of dystrophin, highly expressed during fetal development; increasing endogenous utrophin is a mutation-agnostic strategy with the theoretical potential to be relevant to patients across all DMD genotypes.

About RAG-18

RAG-18 is an investigational small activating RNA (saRNA) developed on Ractigen's proprietary RNAa platform. Administered systemically, RAG-18 targets regulatory regions of the human UTRN gene to induce nuclear, Argonaute-dependent transcriptional activation, increasing endogenous utrophin production. RAG-18 is currently being evaluated in an ongoing first-in-human, open-label, dose-escalation clinical trial (NCT07282652).

About Ractigen Therapeutics

Ractigen Therapeutics is a clinical-stage biopharmaceutical company innovating next-generation RNA therapeutics, with a primary focus on small activating RNAs (saRNAs) developed through its clinically validated RNA activation (RNAa) technology. Leveraging proprietary delivery platforms such as SCAD™, LiCO™, and GLORY™, Ractigen is advancing a robust pipeline addressing unmet medical needs in oncology, neurological diseases, and genetic disorders. Its versatile technologies also enable the rapid development of RNA-based solutions, including siRNAs, where applicable, to target life-threatening, fast-progressing conditions such as those in the CNS. Committed to scientific excellence and patient-centered innovation, Ractigen strives to transform healthcare through the power of RNA therapeutics. For more information, visit www.ractigen.com, and follow us on X and LinkedIn.