Nantong, China, August 7, 2026
Ractigen Therapeutics has announced a significant milestone in the development of its investigational RNA therapeutic RAG-17, confirming the completion of patient enrollment and first-dose administration across all cohorts in its Phase II clinical trial for superoxide dismutase 1 (SOD1)-associated amyotrophic lateral sclerosis (ALS). The achievement represents an important advancement for the company’s clinical development program and highlights strong engagement from both investigators and patients within the rare neurological disease community. Developed using Ractigen’s proprietary SCAD™ (Smart Chemistry-Aided Delivery) platform, RAG-17 is an investigational small interfering RNA (siRNA) therapy designed to selectively silence the SOD1 gene, reducing production of the toxic mutant protein responsible for disease progression in patients with inherited SOD1-ALS. With enrollment completed across five leading clinical centers in China, the study now moves into the critical evaluation phase where investigators will assess safety, pharmacokinetics, pharmacodynamics, biomarkers, and preliminary clinical efficacy. The milestone further strengthens Ractigen’s position in the rapidly growing field of RNA therapeutics and supports its strategy of accelerating the development of innovative treatments for patients with serious neurodegenerative disorders.
Phase II Trial Enters Key Clinical Evaluation Stage
The ongoing Phase II clinical trial (NCT06556394) is a randomized, double-blind, placebo-controlled, multiple ascending dose (MAD) study evaluating repeated intrathecal administration of RAG-17 in patients carrying SOD1 gene mutations. Following the dosing of the first participant in January 2026, Ractigen successfully completed patient enrollment and administered the initial dose to every participant across all study cohorts within a relatively short timeframe. Conducted at five leading neurological research hospitals in China, the study will evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary efficacy of repeated treatment while generating critical clinical data for future regulatory discussions. Completion of enrollment reflects efficient operational execution and demonstrates continued interest from physicians and patients seeking improved treatment options for SOD1-associated ALS, a rare genetic form of the disease with limited therapeutic alternatives. As patients continue treatment, investigators will monitor biomarker responses and functional outcomes that may support subsequent late-stage clinical development.
RAG-17 Uses RNA Technology to Target SOD1 Mutations
RAG-17 has been engineered using Ractigen’s proprietary SCAD™ delivery platform, enabling targeted delivery of siRNA molecules that specifically silence SOD1 messenger RNA. Mutations in the SOD1 gene produce toxic proteins that damage motor neurons and contribute to the progressive muscle weakness characteristic of familial ALS. By reducing production of the mutant protein, the therapy aims to slow disease progression while preserving neurological function. Earlier First-in-Human Phase I clinical results, recently published in Nature Medicine, demonstrated encouraging biological activity, including substantial cerebrospinal fluid (CSF) SOD1 protein suppression and reductions in plasma neurofilament light chain (NfL), an important biomarker associated with neurodegeneration. These findings provided the scientific rationale for advancing into the ongoing Phase II multiple-dose study. The investigational therapy has also received Orphan Drug Designation (ODD) from the U.S. Food and Drug Administration (FDA) and has been selected for the CARE Program by China’s National Medical Products Administration (NMPA), supporting accelerated development for rare diseases with significant unmet medical need.
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RNA Therapeutics Continue Expanding in Rare Neurological Diseases
The successful completion of enrollment strengthens Ractigen Therapeutics’ expanding pipeline of next-generation RNA medicines targeting neurological disorders, oncology, and genetic diseases. Through proprietary delivery technologies including SCAD™, LiCO™, and GLORY™, the company is developing innovative RNA-based therapeutics capable of addressing diseases that have historically lacked effective treatment options. Amyotrophic lateral sclerosis (ALS) remains a devastating progressive neurodegenerative disorder, with most patients experiencing severe disability and death within several years of diagnosis. Individuals carrying SOD1 mutations represent a well-defined patient population for targeted genetic therapies, making RNA interference a promising therapeutic strategy. As the RAG-17 Phase II trial advances into its data collection stage, upcoming safety, biomarker, and functional outcome results will play a critical role in determining the therapy’s future regulatory pathway. Positive findings could further establish RNA therapeutics as an important treatment approach for rare neurological diseases while bringing new hope to patients affected by SOD1-associated ALS, one of the most challenging inherited forms of motor neuron disease.
Source: Ractigen Therapeutics press release
