Novo Nordisk pursues preliminary injunction to block Eli Lilly weight-loss drug ads

COPENHAGEN, July 24 (Reuters) - Novo Nordisk said on Friday it is seeking a preliminary U.S. court injunction to immediately block obesity and diabetes drug advertisements by Eli Lilly.

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.

Lilly on Tuesday denied any wrongdoing, saying it stood by its advertising and would vigorously defend itself. The U.S. drugmaker did not immediately respond to a request for comment outside of U.S. office hours on Friday.

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Novo said in a statement on Friday that Lilly's ads were based on "outdated studies", giving a false impression that the U.S. firm's drugs are vastly superior.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 Nordisk is seeking a court order on an expedited basis to ensure people can access the accurate, complete picture of the treatments available to them today," it said.

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.

Novo's lawsuit seeks a permanent injunction requiring Lilly to withdraw the campaigns and conduct corrective advertising.

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 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.

(Reporting by Maggie Fick, Michael Erman, Stine Jacobsen and Louise Rasmussen; Editing by Essi Lehto, Terje Solsvik and Alexander Smith)