Optimized AAV capsids for basal ganglia diseases show robust potency and distribution

Huntington’s disease and other disorders of the basal ganglia create challenges for biomolecule-based medicines given the poor accessibility of these deep brain structures following intracerebral or intravascular delivery. Here, we found that low dose, low volume delivery of unbiased AAV libraries into the globus pallidus allowed recovery of novel capsids capable of broad access to key deep brain and cortical structures relevant for human therapies. One such capsid, AAV-DB-3, provided transduction of up to 45% of medium spiny neurons in the adult NHP striatum, along with substantial transduction of relevant deep layer neurons in the cortex. Notably, AAV-DB-3 behaved similarly in mice as in NHPs and potently transduced human neurons derived from induced pluripotent stem cells. Thus, AAV-DB-3 provides a unique AAV for network level brain gene therapies that translates up and down the evolutionary scale for preclinical studies and eventual clinical use. To date, brain gene therapies require high vector doses. Here, authors devised an AAV capsid screen and found variants with unprecedented potency for transduction of deep brain and cortical neurons and human iPSC-neurons with cell tropism relevant for Huntington’s and Parkinson’s disease.