Even before right to try laws, terminally ill patients were the preferred clinical trial subject. It's much easier to justify putting a risky chemical into a person who's about to die. Unfortunately, this biases the statistics you get, making it less clear whether the treatment would be helpful in less terminal popuations.
Here's a recent example of a bill passing to allow this, but it's been allowed in various forms before this: https://www.washingtonpost.com/news/to-your-health/wp/2017/0...