[puzzlingcaptcha]

AAV-based vectors are specifically non-integrating. Wild-type AAVs can integrate, but in the absence of rep protein they will instead persist in the cell nucleus in the form of episomal concatemers - long, circular DNA structures containing multiple copies of the virus DNA. These will not replicate when a cell proliferates - they will instead dilute with each division. This makes them desirable for treating diseases affecting post-mitotic tissue like muscle, less so for, say, bone marrow. Unless transient expression (but not as transient as with NLPs) is what you want.

[JPLeRouzic]

Thanks, I thought AAV-based vectors were integrating. Then it's not surprising that some clinical trials using AAV vectors were unsuccessful while the pre-clinical studies were successful, it's looks more a way of cheating than a creating an effective new therapy.