Development of capsid- and genome-modified optimized AAVrh74 vectors for muscle gene therapy.

The first generation of adeno-associated virus (AAV) vectors composed of the naturally occurring capsids and genomes, although effective in some instances, are unlikely to be optimal for gene therapy in humans. The use of the first generation of two different AAV serotype vectors (AAV9 and AAVrh74) in four separate clinical trials failed to be effective in patients with Duchenne muscular dystrophy, although some efficacy was observed in a subset of patients with AAVrh74 vectors leading to US Food and Drug Administration approval (Elevidys). In two trials with the first generation of AAV9 vectors, several serious adverse events were observed, including the death of a patient in one trial, and more recently, in the death of a second patient in an N-of-1 clinical trial. In a fourth trial with the first generation of AAVrh74 vectors, myositis and myocarditis were also observed. Here, we report that capsid- and genome-modified optimized AAVrh74 vectors are significantly more efficient in transducing primary human skeletal muscle cells in vitro and in all major muscle tissues in vivo following systemic administration in a murine model. The availability of optimized AAVrh74 vectors promises to be safe and effective in the potential gene therapy of muscle diseases in humans.
Competing Interests: A.S. is a cofounder of, and has equity in, Lacerta Therapeutics. He also serves on the scientific advisory board of 4D Molecular Therapeutics. He is an inventor on several issued and filed patents on recombinant AAV vectors that have been or are being licensed to various AAV gene therapy companies. B.J.B. is an inventor of AAV-related patents that have been licensed to various AAV gene therapy companies. He is a co-founder and equity holder in Lacerta Therapeutics. D.D. is a member of the scientific advisory board for Solid Biosciences and equity holder in Solid Biosciences. He is also a member of the scientific advisory board of Sardocor Corporation. All of the other authors declare no competing interests.
(© 2023 The Authors.)