Novo Nordisk shares plunge after heart drug Ziltivekimab fails Phase 3 trial

Published Aug 2, 08:33 PM UTC

Novo Nordisk's stock fell sharply on July 31, 2026, after its experimental heart drug Ziltivekimab failed the main goal of the Phase 3 ZEUS trial. The drug, a once-monthly injection targeting inflammation via IL-6 blockade, showed a hazard ratio of 0.99, meaning no reduction in major cardiovascular events compared to placebo. The trial involved over 6,300 patients with atherosclerotic cardiovascular disease, chronic kidney disease, and inflammation. While the drug lowered inflammation markers, this did not translate into clinical benefit. Patients on Ziltivekimab had more serious infections. The failure is a major setback for Novo Nordisk's efforts to diversify beyond its blockbuster weight-loss and diabetes drugs Wegovy and Ozempic. The company expects a non-cash impairment charge in Q3 2026 but maintained its full-year adjusted operating profit outlook. Novo shares have already been under pressure in 2026 due to competition from Eli Lilly's Mounjaro and Zepbound.