These data, combined with previous pre-clinical ICV studies in CLN5−/− sheep (Mitchell et al., 2018; Mitchell et al., 2023a), contributed to the clearance of the CLN5 gene therapy product as an investigational new drug (IND) for the treatment of both the neurological and retinal components of human CLN5 Batten disease and supported the initiation of the current Phase I/II CLN5 gene therapy clinical trial testing scAAV9/hCLN5 dual route ICV/IVT administration (Clinicaltrials.gov identifier: NCT05228145). This evidence concerns the gene CLN5 and juvenile neuronal ceroid lipofuscinosis.