Nixon signed the law that banned television and radio advertisements for tobacco, and the companies stopped trying to fight that after the master settlement agreement in the 1990's. Basically, the states said we have proof you engaged in a decades-long campaign to knowingly mislead the public on the safety of your products. In return, you need to pay a boatload of money to reimburse medicare expenses for tobacco users. And you need to stop all fights against the advertising bans. And further you need to stop advertising anywhere your ads can be seen by kids. This is why you no longer see tobacco ads on outdoor billboards, transit ads, most magazines, or sponsorships of sports teams, or other events. And you no longer see the marlboro man, joe camel, etc.

I think to connect this precedent to the drug industry, you need to show a pattern of deception and misleading claims. Drug companies skirt this by including the quick disclaimers at the end of their ads.