I mean, I did a quick scan and there was this...I'm sure 21CFR312 has more to say but....
"This provision is not intended to restrict the full exchange of scientific information concerning the drug, including dissemination of scientific findings in scientific or lay media. Rather, its intent is to restrict promotional claims of safety or effectiveness of the drug for a use under which it is under investigation and to preclude commercialization of the drug before it is approved for commercial distribution.”