Tissue distribution pharmacokinetics of intrathecal U1 adaptor oligonucleotide in mice.

U1 Adaptor is a novel gene-silencing technology, offering an innovative approach to target genes in the CNS for the treatment of diseases. Intrathecal delivery is a medically viable route of administration of CNS-bound nucleic acid drugs; therefore, it is important to investigate U1 Adaptor distribution after intrathecal drug delivery. We investigated the distribution patterns of U1 Adaptor upon intrathecal bolus administration in mice. It readily distributes to CNS tissues, including the lumbar and the cervical spinal cord, and the cerebellum. Over time, the U1 Adaptor also accumulates in the periphery, both in the liver and the kidneys, while plasma levels are undetectable. Our findings provide useful information for future in-depth pharmacokinetic modeling of U1 Adaptor distribution upon intrathecal administration.