Novo Nordisk sues Eli Lilly over alleged false advertising, shares fall

Novo alleges that Lilly violated federal and state false advertising and unfair competition laws, including the Lanham Act, through nationwide advertising campaigns for obesity drug Zepbound and diabetes treatment Mounjaro.

Novo says Lilly compared the highest approved doses of its medicines with lower doses of Novo's Wegovy and Ozempic while omitting newer, higher-dose versions that Novo says deliver greater weight loss.

Up to the last close, NVO was down 2.5% year to date.

U.S.-listed shares of Danish drugmaker Novo Nordisk fell 1% to $49.07 in premarket trading after the company sued rival Eli Lilly in a U.S. federal court.

Novo accused the U.S. drugmaker of false advertising in claiming its weight-loss medicines outperform Novo's drugs. Shares of Lilly fell 0.7% in premarket trading.