Comparative assessment of the transduction efficiency and safety associated with the delivery of AAV9-GFP vector via lumbar puncture to cynomolgus macaques with and without anti-AAV9 pre-existing antibodies

Administration of AAV-based gene therapies into the intra-cerebrospinal fluid (CSF) compartments via routes such as lumbar puncture (LP) has been implemented as an alternative to intravenous dosing to target the CNS regions. This route enables lower doses, decreases systemic toxicity, and circumvents intravascular pre-existing anti-AAV antibodies. In this study, AAV9-GFP vectors were administered via LP to juvenile cynomolgus macaques with and without pre-existing serum anti-AAV9 antibodies at a 5.0 × 10¹³ vector genomes per mL (vg/mL) dose and examined for 28 days. CNS and peripheral tissues were surveyed for vector genome, mRNA, and protein expression. Histopathology, clinical pathology, and humoral immune response to the viral capsid and transgene were also assessed. In addition, serum and CSF samples were analyzed to examine 276 proteomic markers curated to evaluate neural injury, organ damage, and inflammatory response. This study reveals no noticeable difference in AAV9-mediated gene transfer in the CNS tissues in the two groups; however, differences were observed for endpoints such as liver enzyme activities, histopathology, and levels of protein markers in the serum and CSF. These findings provide a view into vector transduction efficiency and safety following LP-delivered AAV9 to juvenile cynomolgus macaques with and without pre-existing anti-AAV9 antibodies.