A Barrel of Monkeys: scAAV8 Gene Therapy for Hemophilia in Nonhuman Primates

In this issue of Molecular Therapy, Nathwani et al. present outstanding nonhuman primate (NHP) experiments1 performed as a prelude to a human trial that has already been hailed as achieving the “holy grail” of hemophilia B gene therapy.2 The aims of the preclinical studies were to determine the safety, efficacy, dose requirements, and immune responses after peripheral intravenous delivery of a self-complementary adeno-associated viral vector (AAV), sc-AAV-LP1-hFIXco, pseudotyped with either AAV8 or AAV5 capsid.