It’s true in general that economics, with patents being part of that, is the dominant influence on r&d resources. However the effective research ban is by far

It’s true in general that economics, with patents being part of that, is the dominant influence on r&d resources. However the effective research ban is by far the bigger limiting factor in this case, because it rules out most options before even getting started. For example, it’s not unusual for unpatentable substances to be studied, in the hope that understanding the fundamental mechanism could allow a (sometimes) improved alternative to be developed that could be profitable. There is also at least some research not controlled by big pharma that could have conceivably targeted these areas 40 years ago.