Novo Nordisk shares plunge 13.8% after experimental obesity drug CagriSema failed to meet primary endpoints in an 84-week head-to-head trial against Eli Lilly's Tirzepatide. The Copenhagen-based pharmaceutical giant's stock dropped sharply Monday following the disappointing results in the competitive weight loss medication market.

The trial revealed patients taking CagriSema achieved 23% weight loss compared to 25.5% for those using Tirzepatide. Novo confirmed the study "did not achieve its primary endpoint of demonstrating non-inferiority" on weight reduction, dealing a blow to their efforts to maintain dominance in the burgeoning obesity treatment sector.

Novo faces mounting challenges from Lilly and telehealth firms offering cheaper alternatives. After shares plummeted 49% in 2025, the company nominated two drug industry veterans to its board and installed Lars Rebien Sorensen as chairman, signaling a strategic response to intensifying competition in the lucrative weight management market.