Do drug companies' arguments that they are entitled to freedom of speech hold any water? I know people like to overemphasize the effects of Citizens United, et

Do drug companies' arguments that they are entitled to freedom of speech hold any water? I know people like to overemphasize the effects of Citizens United, etc But I am curious if they could solely win on a speech argument. If so, one would think all sorts of advertising regulations would be easily overturned.