Accessing the subarachnoid space via intrathecal needle placement can be done in nonhuman primates (NHPs) and other species to collect cerebral spinal fluid (CSF) or to deliver agents into the CSF.

Direct delivery of recombinant IL-10, however, has been found to be impractical because IL-10 does not cross the blood–brain barrier 5 and, when given IT, its half-life of elimination in the CSF is 2 ...