Oligonucleotide therapeutics, including antisense oligonucleotides (ASOs) and siRNAs, have become an important treatment strategy for central nervous system (CNS) disorders. Because these large, negatively charged molecules cannot efficiently cross the blood-brain barrier, intrathecal administration delivers them directly into the cerebrospinal fluid (CSF), enabling effective distribution throughout the CNS while reducing systemic exposure and improving therapeutic efficacy.
Intrathecal delivery has been clinically validated by therapies such as nusinersen for spinal muscular atrophy and is increasingly used in the development of treatments for neurodegenerative diseases. Following administration, oligonucleotides distribute rapidly within the CNS, exhibit prolonged tissue residence, and are primarily metabolized by nucleases before renal elimination. Consequently, preclinical studies should evaluate both systemic pharmacokinetics and CNS-specific parameters, including drug distribution, metabolite profiles, CSF exposure, and pharmacodynamic biomarkers in brain tissues.
As CNS drug development continues to advance, reliable intrathecal dosing and CSF sampling techniques are essential for generating high-quality PK/PD data. Robust preclinical platforms that integrate intrathecal administration with comprehensive CNS pharmacology studies can accelerate the development and translation of oligonucleotide therapeutics targeting neurological diseases.
