Company: "But that's a naturally occurring virus, we can't patent that so we're not interested. Do something else, or find a way to 'make it better' so we we can patent it and make money."
True story. Now imagine this:
Researcher: "I've found that this rhinovirus is devastating to certain kinds of tumors when injected into them... in mice. We need to do more testing, and in humans."
Oncologist at major center: "We've seen a number of terminal patients with that type of cancer, current treatments don't work especially at stage 4. We could test that virus on a number of people if they were willing to try it."
Cancer Patient "Sign me up!"
There has to be a way to make this work, and it should cost far less than the current approach. I'd argue that it would cost the government less to fund the studies than to pay medicaid costs for the patented treatments. Sure, change would need to happen but it would happen fast, and in the mean time nobody would eliminate current treatments - they're already established and profitable.
As an example of exploitation see the statin drugs used to lower cholesterol. These were originally isolated from an ancient Chinese herbal "red yeast rice" and found to be effective. So some company patented the molecule, did clinical trials, and profit! I chose this one because I have personal experience getting dramatic reduction in my cholesterol from taking red-yeast-rice. It's also a nice example of how the system is broken. We all could have benefited from trials proving that red-yeast-rice reduces cholesterol, but that's not what happened. The company would not have funded the trials if they couldn't patent the molecule.
IMHO if clinical trials were cheaper there would be no need for granting monopolies (via patents) to cover the costs. I also don't see why trials are so expensive. There are plenty of doctors treating plenty of patients that are willing to try things. All we really need is a set of rules to protect people from irresponsible trials, and formal study procedures to document results and determine efficacy. It doesn't seem too complicated right?