Novo Nordisk and Eli Lilly clash over weight-loss drug adverts

Novo Nordisk said Tuesday it is suing US rival Eli Lilly over adverts for competing weight-loss and anti-diabetes treatments that the Danish company described as false and materially misleading.

Novo Nordisk, which makes Wegovy and Ozempic, said Eli Lilly, maker of Zepbound and Mounjaro, intentionally selected outdated studies that compared Lilly's highest doses with lower doses of Novo Nordisk's medicines. Novo Nordisk said the adverts presented those results as evidence of broad product-level superiority while leaving out important clinical context.

Novo Nordisk has developed semaglutide, while Eli Lilly has developed the rival molecule tirzepatide. The drugs have become financially important products for both companies.

Novo Nordisk general counsel John F. Kuckelman said people need accurate information based on the latest scientific evidence as more treatment options become available. He said healthcare companies must keep public claims accurate and current, and that fine-print disclaimers do not correct what he described as a misleading impression from large national campaigns.

Novo Nordisk said the advertising campaign aired during recent widely watched global sporting broadcasts and appeared on TikTok and Facebook, causing confusion.

Eli Lilly rejected the accusations. A spokesperson told AFP that the Surmount-5 trial behind its advertising is the only direct, head-to-head randomised clinical trial comparing tirzepatide and semaglutide for weight management. The spokesperson said Novo Nordisk was asking a court to stop Lilly from communicating the trial results, and said Lilly stands by the campaign.

Anti-obesity treatments mimic GLP-1, a hormone secreted by the intestines. They can be used for weight loss and, or, to treat type 2 diabetes, the most common form of diabetes.