It seems to me to be similar to the approval of the three Alzheimer's drugs which don't really show improvement either- it seems like over the past decade the FDA has wanted to approve drugs that might work for diseases where there was no treatment at all (while saying things "delivering hope"). And it's not gone well, and has not been a good idea.

https://www.axios.com/2025/04/18/rfk-jrs-potential-future-ta...

https://kffhealthnews.org/news/article/nih-grants-mrna-vacci...

> National Institutes of Health officials have urged scientists to remove all references to mRNA vaccine technology from their grant applications, two researchers said, in a move that signaled the agency might abandon a promising field of medical research.

Reasons to use AAV: they're going for sustained production of the therapeutic gene, and AAVs are better at doing that than LNPs. LNPs were used in the mRNA COVID vaccine, because they're great at transient production.

To get stable production from an LNP you'd likely have to integrate into the genome, which risks cancer from disrupting oncogenes. You'd also need to package the therapeutic gene with a mechanism of integrating into the genome, like recombinase.

https://www.science.org/content/blog-post/sarepta-s-approval... ("Sarepta's Approval Woes" (2013))

https://www.science.org/content/blog-post/sarepta-s-duchenne... ("Sarepta's Duchenne Therapy Is A Lot Further Away" (2014))

https://www.science.org/content/blog-post/sarepta-s-day-fda ("Sarepta's Day at the FDA " (2016))

https://www.science.org/content/blog-post/sarepta-gets-appro... ("Sarepta Gets An Approval - Unfortunately" (2016))

https://www.science.org/content/blog-post/gene-therapy-duche... ("Gene Therapy for Duchenne" (2018))

https://www.science.org/content/blog-post/opening-lid-sarept... ("Opening the Lid on Sarepta's Drug Approvals" (2020))

https://www.science.org/content/blog-post/sarepta-tries-agai... ("Sarepta Tries Again" (2023))

https://www.science.org/content/blog-post/sarepta-why ("Sarepta. Why?" (2024))