Novo Nordisk’s phase 3 Zeus trial suffered a negative result for ziltivekimab, an IL-6 pathway inhibitor being tested for cardiovascular risk reduction in people with atherosclerotic cardiovascular disease, chronic kidney disease, and inflammation. The mechanism reduced IL-6 signaling and knocked down high-sensitivity C-reactive protein, but it did not translate into a significant reduction in major adverse cardiovascular events versus placebo. Novo reported a hazard ratio of 0.99 (95% CI 0.88–1.11) across more than 6,300 enrolled patients. The update follows a broader question in cardiology and inflammation-driven drug development: whether upstream cytokine blockade yields clinical benefit in at-risk populations selected by biomarkers. Following the data, shares fell sharply, highlighting how single phase 3 readouts can quickly reprice the probability of success for late-stage cardiovascular inflammation programs.