So, so many companies have been caught promoting drugs "off-label", for uses that the FDA hasn't approved. So many. Johnson & Johnson paid $1.4 BILLION to settle a suit alleging that they heavily promoted the use of antipsychotics on dementia patients.
If J&J thought their drugs worked, I'd naively think that they could just invest a (perhaps significant) fraction of the eventual settlement to prove as much to the FDA. It would boost sales and allow them to promote them indefinitely, out in the open.
Either they couldn't be bothered, or in fact they tried to prove it, and failed. If J&J can't prove a drug works, the odds that it does actually work seems... low, given the amount of resources J&J have.
I'd be a fuckton more surprised if there weren't hundreds of companies trying to sell drugs regardless of efficacy.