Translational Feasibility of Lumbar Puncture for Intrathecal AAV Administration

Abstract

Preclinical studies have demonstrated that a single injection of an adeno-associated virus (AAV) vector into the cerebrospinal fluid (CSF) can achieve widespread gene transfer throughout the central nervous system. Successfully translating this approach to humans requires identifying factors that influence AAV distribution in the CSF so that optimal parameters can be replicated in the clinic. In the context of developing a motor neuron-targeted gene therapy for spinal muscular atrophy, we conducted studies in nonhuman primates to evaluate the impact of injection volume on spinal cord transduction after AAV delivery via lumbar puncture. Lumbar injection of an AAVhu68 vector targeted motor neurons throughout the spinal cord, but only in juvenile nonhuman primates administered large injection volumes, equivalent to about half of the total CSF volume. Upon repeating this study with clinically relevant injection volumes and larger animals, we found that lumbar puncture failed to achieve significant transduction of the spinal cord. In contrast, vector administered into the cisterna magna distributed reproducibly throughout the spinal cord in both juvenile and adult animals. These findings highlight the challenges of translating AAV delivery via lumbar puncture to humans and suggest that delivery into the cisterna magna may represent a more feasible alternative.

Efficacy of AAV serotypes to target Schwann cells after intrathecal and intravenous delivery

“…Ramsingh et al (2018) showed efficient transduction using AAV9 42 , while Hinderer et al (2020) showed that intrathecal injection of AAVrh78 failed to transduce the CNS in older animals using large injection volumes but was efficient in younger animals. In contrast, intra-cisterna magna injection proved to be efficient in both young and older animals at lower volumes 29 . Further, a suboccipital administration into the CSF (intrathecal) of infant monkeys of AAV9 resulted in sustained expression up to 4 years showing that intrathecal injection is an efficient and safe way of delivery 43 .…”

“…Lumbar intrathecal delivery could be the safest and most effective route of administration to target both CNS and PNS as it has been show to result in widespread expression of both AAV9 23 , 26 , 27 and AAVrh10 14 , 16 , 17 , 28 although recent data indicate that it may not achieve the necessary CNS biodistribution for translation in humans 29 . Studies are mainly focused on the CNS biodistribution while there are data showing that both vectors can reach the sciatic nerve 14 , 16 , 17 , 23 although with no targeted expression.…”

AAV ablates neurogenesis in the adult murine hippocampus

“…Despite high rates of infection among humans (Thwaite et al, 2015), AAV infection has not been associated with illness or pathology (Büning and Schmidt, 2015). However, recent reports have suggested rAAV may exhibit intrinsic toxicity in multiple tissues (Bockstael et al, 2012;Flotte and Büning, 2018;Hinderer et al, 2018;Hirsch et al, 2011;Hordeaux et al, 2018).…”

“…Despite its safety profile, rAAV has increasingly been reported to demonstrate toxicity in some cell types (Bockstael et al, 2012;Hinderer et al, 2018;Hirsch et al, 2011;Hordeaux et al, 2018). However, the toxic effects of rAAV on abDGCs have previously not been assessed.…”

Gene Therapy for Lysosomal Storage Disorders: Ongoing Studies and Clinical Development

“…While gene expression following IT injection in mice is restricted to the lower segments of the spinal cord, delivery to larger animals such as pigs [ 245 ] and NHPs [ 246 ] results in more diffuse transduction of the spinal cord and brain. However, studies conducted by Hinderer and colleagues showed that intrathecal delivery resulted in lower gene expression in the cervical section of the spinal cord and in the brain compared to other CSF delivery methods [ 247 , 248 ], even when the animals were placed in the Trendelenburg position after injection [ 249 ]. Nevertheless, the lumbar puncture procedure is widely used in the clinic.…”