Preclinical safety and biodistribution of CRISPR targeting SIV in non-human primates

Tricia H. Burdo, Chen Chen, Rafal Kaminski, Ilker K. Sariyer, Pietro Mancuso, Martina Donadoni, Mandy D. Smith, Rahsan Sariyer, Maurizio Caocci, Shuren Liao, Hong Liu, Wenwen Huo, Huaqing Zhao, John Misamore, Mark G. Lewis, Vahan Simonyan, Elaine E. Thompson, Ethan Y. Xu, Thomas J. Cradick, Jennifer Gordon, Kamel Khalili

In this study, we demonstrate the safety and utility of CRISPR-Cas9 gene editing technology for in vivo editing of proviral DNA in ART-treated, virally controlled simian immunodeficiency virus (SIV) infected rhesus macaques, an established model for HIV infection. EBT-001 is an AAV9-based vector delivering SaCas9 and dual guide RNAs designed to target multiple regions of the SIV genome: the viral LTRs, and the Gag gene. The results presented here demonstrate that a single IV inoculation of EBT-001 at each of 3 dose levels (1.4 × 1012, 1.4 × 1013 and 1.4 × 1014 genome copies/kg) resulted in broad and functional biodistribution of AAV9-EBT-001 to known tissue reservoirs of SIV. No off-target effects or abnormal pathology were observed, and animals returned to their normal body weight after receiving EBT-001. Importantly, the macaques that received the 2 highest doses of EBT-001 showed improved absolute lymphocyte counts as compared to antiretroviral-treated controls. Taken together, these results demonstrate safety, biodistribution, and in vivo proviral DNA editing following IV administration of EBT-001, supporting the further development of CRISPR-based gene editing as a potential therapeutic approach for HIV in humans.