This wiki article is probably the best place to start:

https://en.m.wikipedia.org/wiki/Death_of_Wei_Zexi

Then there was some movement on the issue in 2019:

https://www.bloomberg.com/news/features/2019-12-10/cancer-tr...

I’m not sure where they ended up due to COVID happening next.

IIRC it did, though the cynic in me would suggest that by “this kind of corruption” what it prevents is the kind of corruption that government officials don't benefit from.

I trust the Chinese government less than I trust my own with regard to doing the right thing (just because it is the right thing or indeed at all), and that is a pretty low bar…

The regulation is approval by a governmental agency through clinical trials