NCBI - both articles show uses of multiple treatments and iverm3ctn, not IVM alone.
Euro articles - both do not mention IVM.
Here's much better although still not perfect info I found from my searching:
https://cannabiscancersite.wordpress.com/2021/12/23/the-truth-about-japan-and-ivermectin/ @SteveKirsch look at this, better than your source