Actually I have wondered on occasion who funds the drug studies that aren't funded by the manufacturer. The FDA?
The FDA requires the drug companies to do certain studies, but doesn't fund them. Basically the manufacturer goes to the FDA before human testing, and says "Here's the results! We want to test humans!" and the FDA says OK or not. And then after that, between testing healthy people, and testing lots of people, they meet with the FDA a few more times to say "This is the results! This is what we plan to test next" and sometimes the FDA says "OK" and sometimes they say "Actually, we also want you to do some tests with people who are on your drug and on (something elese)" or "also add in some neurological tests to make sure your drug doesn't do what (other drug) does" etc.
Most non-industry drug studies are...incredibly smaller. And are funded by things like the NIH, the National Cancer Institute or suchlike, or associations. But often those are just working WITH drug companies on drugs they might otherwise not be able to study, or in ways they might not otherwise.
I have that book in my queue, but I have to say, having worked on the research side (including a LOT of studies that didn't work!), I think the corrupt and icky parts are less the research, and more the "OK, what are we going to develop? Possible new drug that would cost $40 million to do and might not work? Or could we just do some studies to see if our already-approved depression drug also works for bipolar?" or "Hey, let's make more money by pointing out that if we separate our good compound into two, because it's only one form of it that works, we can charge extra and extend our patent life!" and then the sales side ("Well, we haven't actually done STUDIES on migraine, but I'm just saying a lot of doctors prescribe off-label, hint hint" which some companies have gotten in big trouble for).