While browsing the short videos, I came across something about "Aim injection" to treat KD cats. Here is a write up by barkandwhiskers.com here and I looked into the information a bit more, seems the injection is currently in clinical trail (trail began in late 2022). Here is another writeup by the University of Tokyo.
But I could not find anything other than these info.
While the injection could be years from North America market, I sincerely hope it will be available soon. Just to see if anyone have more information about this.
The article from University of Tokyo was published in 2020. The descriptive piece that you didn't link is here. While this piece notes that there is an AIM (apoptosis inhibiting macrophage) based food that is being produced in Japan, it is dry food. The article also lists the ingredients in the food. The ingredients are not something I would want to feed my cat and are wholly inappropriate for a diabetic cat. The author of the article notes the problem with the food. The treatment that is only alluded to is a combination of the AIM food and a medication.
The research that is available appears to be in preliminary stages and with mice only. There was nothing I saw that indicated that AIM treatment is a cure. If you do a search (I used Google Scholar) for apoptosis inhibiting macrophage and kidney disease, it looks like this line of research has been going on since 2013.
Given the relationship between diabetes and kidney disease, if the research was gaining traction, I suspect that we would have heard more about it.