Directed evolution of a family of AAV capsid variants enabling potent muscle-directed gene delivery across species

Replacing or editing disease-causing mutations holds great promise for treating many human diseases. Yet, delivering therapeutic genetic modifiers to specific cells in vivo has been challenging, particularly in large, anatomically distributed tissues such as skeletal muscle. Here, we establish an in vivo strategy to evolve and stringently select capsid variants of adeno-associated viruses (AAVs) that enable potent delivery to desired tissues. Using this method, we identify a class of RGD motif-containing capsids that transduces muscle with superior efficiency and selectivity after intravenous injection in mice and non-human primates. We demonstrate substantially enhanced potency and therapeutic efficacy of these engineered vectors compared to naturally occurring AAV capsids in two mouse models of genetic muscle disease. The top capsid variants from our selection approach show conserved potency for delivery across a variety of inbred mouse strains, and in cynomolgus macaques and human primary myotubes, with transduction dependent on target cell expressed integrin heterodimers. [Display omitted] •A family of muscle-tropic capsids identified by directed evolution in mice and primates•MyoAAV transduction is dependent on integrin heterodimers in mouse and human cells•MyoAAV administration at low dose results in therapeutic efficacy in disease models•Systemically administrated MyoAAV transduces primate muscles highly efficiently Tabebordbar et al. evolved a family of RGD-containing AAV capsid variants in mice and primates that enable highly effective systemic gene delivery to muscles. They show these capsids are dependent on integrin heterodimers for transduction across species and enable achieving therapeutic efficacy after systemic administration at low dose.