NANTONG, China, Jan. 13, 2026 -- Ractigen Therapeutics is pleased to announce that the first patient has been dosed in the Phase II clinical trial of RAG-17, an innovative siRNA therapy targeting SOD1-mutated amyotrophic lateral sclerosis (ALS). The initial dosing occurred at Second Affiliated Hospital, Zhejiang University School of Medicine, under the leadership of Dr. Zhi-Ying Wu, head of the Department of Medical Genetics/Center for Rare Diseases.

This Phase II trial is a randomized, double-blind, placebo-controlled, multiple ascending dose (MAD) study designed to evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of repeated intrathecal injections of RAG-17 in patients with SOD1 mutations. The participating sites include Beijing Tiantan Hospital, Capital Medical University (led by Dr. Yi-Long Wang), The Second Affiliated Hospital, Zhejiang University School of Medicine (led by Dr. Zhi-Ying Wu), West China Hospital of Sichuan University (led by Dr. Hui-Fang Shang), Fujian Medical University Union Hospital (led by Dr. Zhan-Yu Zou) and the First Affiliated Hospital, Sun Yat-sen University (led by Dr. Jing-Sheng Zeng) .

This milestone marks the progression into the Phase II stage of the study, building on the successful completion of the Phase I single ascending dose (SAD) portion. The transition to the Phase II MAD phase was supported by highly encouraging data from the SAD study, which demonstrated an exceptional safety profile and sustained biomarker modulation following a single injection, including significant reductions in CSF SOD1 protein and improvements in plasma neurofilament light chain (NfL) levels. These results validate the capability of our proprietary SCAD™ delivery platform for central nervous system (CNS) in humans.

Dr. Long-Cheng Li, Founder and CEO of Ractigen Therapeutics, emphasized Ractigen's dedication to advancing treatments for ALS: "The successful dosing of the first patient represents a significant milestone in our mission to develop transformative therapies for ALS. The positive results from the Phase I trial affirm the promise of RAG-17 and provide us with strong confidence in its potential to markedly improve the lives of patients suffering from SOD1-mutated ALS."

Dr. Zhi-Ying Wu shared optimistic expectations for the Phase II trial: "We are excited to be part of this important study. Based on the improvements we have observed clinically, we look forward to further investigating RAG-17's potential to enhance the quality of life for ALS patients as we progress."

About RAG-17
RAG-17 is an investigational siRNA therapeutic candidate designed using Ractigen's proprietary SCAD™ delivery platform technology to specifically target and silence the superoxide dismutase 1 (SOD1) gene mRNA. Mutations in the SOD1 gene cause a toxic gain-of-function and are a known cause of familial ALS. By reducing the production of the toxic mutant SOD1 protein, RAG-17 aims to slow or halt the progression of SOD1-ALS.

RAG-17 has obtained Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) and been selected for the CARE Program of the Center for Drug Evaluation (CDE), National Medical Products Administration (NMPA), which facilitates the accelerated development of rare disease therapies.

About ALS
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disease affecting nerve cells in the brain and spinal cord, leading to muscle weakness, paralysis, and ultimately death, typically within three to five years of diagnosis. SOD1 gene mutations account for approximately 10-20% of familial ALS cases and about 1-2% of sporadic ALS cases. There remains a critical unmet medical need for effective treatments that can slow or stop disease progression.

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.