Novo Nordisk’s IL-6 inhibitor ziltivekimab missed its primary clinical objective in the late-stage ZEUS trial, failing to reduce cardiovascular events in a population spanning atherosclerotic cardiovascular disease, chronic kidney disease and inflammation. Novo said the results dashed expectations that biomarker-linked inflammation changes would translate into major adverse cardiovascular event (MACE) risk reduction. The company reported that ziltivekimab did not achieve the hoped-for MACE benefit, with shares falling nearly 9% to about $47.10 in Friday trading. Analysts had framed the program as a high-risk/high-reward bet aimed at finding differentiation as the IL-6 pathway competed in a crowded cardiometabolic market. Novo noted that earlier data suggested C-reactive protein reductions, but the biomarker improvement did not produce the same directionality in clinical outcomes. ZEUS complete results are expected later this year. Development is not fully closed: ziltivekimab is also being studied in heart failure (HERMES) and acute heart attack (ARTEMIS), with readouts expected in the first half of next year, but the immediate setback alters the probability of benefit for the broader cardiovascular inflammation hypothesis.