Novo Nordisk seeks preliminary injunction against Lilly weight-loss ads

Denmark's Novo said on Tuesday it had sued Lilly, arguing consumers were being misled about how the companies' products compare, and that it would seek a preliminary injunction if the U.S. group did not voluntarily remove the disputed ads.

"What it shows from my perspective is that Novo is taking a more aggressive stance in managing its business -- they're not just going to let Lilly say whatever they want," Seigerman said.

What we know

Novo and Lilly are battling for dominance in the obesity drug market, which analysts expect to be worth more than $100 billion by the end of the decade in the United States alone. Novo said in a statement on Friday that Lilly's ads were based on "outdated studies", giving a false impression that the U.S. firm's drugs are vastly superior.

Novo's lawsuit alleges that Lilly violated false advertising and unfair competition laws through its campaigns for obesity drug Zepbound and diabetes treatment Mounjaro. Novo claimed Lilly compared the highest approved doses of Zepbound and Mounjaro with lower doses of Novo's Wegovy and Ozempic while omitting newer, higher-dose versions of Novo's medicines that it says deliver greater weight loss.

BMO analyst Evan Seigerman said the lawsuit was a way for Novo to try to change public perception of how the two companies' drugs perform.

What to watch

Lilly on Tuesday denied any wrongdoing, saying it stood by its advertising and would vigorously defend itself.