RU58841 is only available as a research chemical and for research purposes. You can see on the right side a overview of legitimate tested sources where you can buy RU58841. Many people might find that strange. After all why did RU58841 never reach to the market as a drug by prescription like for instance finasteride?
Nobody knows the exact reason. What we do know however is that Prostrakan was searching for partnering discussions for RU58841 after their 2nd clinical trial. Out-licensing was a key part of the strategy of Prostrakan but they did identify RU58841 as a value project but not a priority one. You can see the exact information about that in the following picture of a Morgan Stanley report about Prostrakan;
The interesting thing about the report is that RU58841 compared well with historical data from finasteride. Furthermore they find the market for RU58841 to be “reasonably modest” indicating a market value of $100-200 million and that it specifically could be of interest of to a special dermatology company.
Perhaps it is reasonable to assume that RU58841 never got through because of financial reasons. Maybe no company really wanted to go through with RU58841 into further clinical trials because the agent wouldn’t generate much revenue.
The factors that maybe played into this is that finasteride was already on the market. Ru58841 would have to compete with finasteride and a pill is easier to swallow than applying a topical once a day to your scalp. Also Propecia wasn’t actually a financial success for Merck at all.
Another important factor is that the patent for RU58841 was already quite old when the second clinical trial was finished. If a company would go forward to bring RU58841 to the market then it would only have a short amount of time to generate revenue before other companies could compete and create generic versions.
So perhaps Ru58841 just did not go through because of financial reasons. After all we pretty much all know that the priority goal of pharmaceutical companies is to create revenue. If they won’t see bread in something they will be happy to drop it.