Lumbar Intrathecal Injection of SOD1-ASOs for Precise CNS Targeting and Predictive Efficacy in Human SOD1-G93A ALS Mice

Intrathecal (IT) administration of central nervous system (CNS)-targeted therapeutics offers a minimally invasive route for direct drug delivery into the cerebrospinal fluid (CSF), facilitating enhanced specificity and target engagement. While IT catheterization is standard for sustained delivery in rats, its application in mice is limited by anatomical constraints and elevated risk of procedure-related complications, including spinal injury and infection. To overcome these limitations, we employed an acute needle puncture technique for IT drug delivery in adult mice, providing a reproducible and less invasive alternative compatible with single or repeated dosing regimens. In a transgenic mouse model of amyotrophic lateral sclerosis (ALS) harboring the SOD1-G93A mutation, we achieved efficient IT delivery of antisense oligonucleotides (ASOs) targeting the SOD1 gene. This approach effectively downregulated mutant SOD1 expression and significantly ameliorated the disease phenotype, as demonstrated by electrophysiological and biomarker assessments. These results validate both the IT delivery method and the therapeutic efficacy, with outcomes comparable to intracerebroventricular (ICV) administration. Most importantly, the technique mirrors procedures used in human clinical studies, offering strong translational relevance and utility in preclinical evaluation of CNS-directed interventions. Although technical expertise is required to ensure consistency and avoid off-target effects, this IT delivery strategy represents a robust, reproducible, and clinically relevant methodology for advancing therapeutic development in small animal models.