I'm not sure that "can't be patented / manufacture is no secret" is necessarily the research bottleneck here, because you can make a lot of money selling analog

I'm not sure that "can't be patented / manufacture is no secret" is necessarily the research bottleneck here, because you can make a lot of money selling analogs or derivatives of old, boring drugs. There was an interesting ProPublica story recently about a drug manufacturer raising the price of their (patented) cancer drug to eye-watering levels... and the drug in question is an analog of thalidomide! https://www.propublica.org/article/revlimid-price-cancer-celgene-drugs-fda-multiple-myeloma https://www.propublica.org/article/revlimid-price-cancer-cel... One of the claims against this company is that they were preventing other companies from getting their hands on generic thalidomide, because they didn't want competitors to do research that might uncover similar analogs. (I'm also not convinced that the results for methylene blue are especially promising or unique, but that's another matter :P)