Earlier quoted context omitted.
we are seeing new antibiotics. Largely because of the costs of FDA regulation compliance, it costs ~$1-2 billion to develop the average new drug. http://en.wikipedia.org/wiki/Pharmaceutical_industry#The_cos... How many potential drugs, each year, have not been developed, because of the difference between that cost and the potential cost in a zero-regulation environment? Thousands? Millions?
A better question would be "How many potential drugs have not been developed because they cannot be patented?" Oh, and a zero regulation environment? There's always going to be liability for "your drug killed people". In a zero regulation environment that cost is going to be incredibly high. Or your placebo drug is going to CAUSE economic damage by killing productive workers. Your model of regulation/no-regulation is…
It depends on why they couldn't be patented. There's a nasty interaction between regulatory delay and patent terms starting at application which means that drugs that don't have huge markets don't get developed, but I'm pretty sure that you're not referring to those.
Let me guess - you think that there are substances which are unpatentable because they fail the novelty test but have great utility as drugs. If said utility is newly discovered, that satisfies the novelty test. If said utility is "folk medicine", then the only thing stopping anyone from selling them as drugs is the regulatory testing costs.... (Drugs don't have to be patented.)