Novo Nordisk announced Friday that its experimental heart drug ziltivekimab failed to reduce major adverse cardiovascular events in a late-stage clinical trial, sending the Danish drugmaker's stock lower.
The experimental anti-inflammatory drug ziltivekimab did not reduce major adverse cardiovascular events compared with a placebo in a study of more than 6,300 patients
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Novo Nordisk announced Friday that its experimental heart drug ziltivekimab failed to reduce major adverse cardiovascular events in a late-stage clinical trial, sending the Danish drugmaker's stock lower.
The ZEUS trial enrolled more than 6,300 people with atherosclerotic cardiovascular disease, chronic kidney disease, and elevated inflammation. The study tested whether ziltivekimab, a once-monthly injection that blocks the IL-6 inflammatory pathway, could cut the risk of cardiovascular death, non-fatal heart attack, or non-fatal stroke compared with placebo on top of standard care. The hazard ratio came in at 0.99, with a 95% confidence interval of 0.88 to 1.11, meaning the drug produced no meaningful risk reduction, the company said.
Ziltivekimab did produce the expected biological effect — reducing free IL-6 and high-sensitivity C-reactive protein levels — but that effect did not translate into clinical benefit, Novo Nordisk said.
"Although ziltivekimab produced the expected biological effect, this did not result in MACE benefits in this population," Martin Holst Lange, executive vice president, chief scientific officer, and head of Research and Development at Novo Nordisk, said in a statement. "The study provides important scientific evidence that will inform our ongoing cardiovascular research."
The safety profile showed broadly comparable adverse-event rates across both arms of the trial, with the exception of serious infections, which occurred more frequently in patients who received ziltivekimab. Deaths from any cause occurred at similar rates in both groups, the company said.
Copenhagen-listed Novo Nordisk stock dropped as much as 10% on Friday. Its American depositary receipts were trading 8.6% lower in premarket hours.
The trial result will not affect the company's adjusted operating profit outlook for 2026, but Novo Nordisk said it will record a non-cash impairment charge in the third quarter. Two other cardiovascular trials testing ziltivekimab — HERMES in heart failure patients and ARTEMIS in patients following an acute heart attack — are continuing and are expected to produce results in the first half of 2027.
Friday's news adds to a difficult stretch for Novo Nordisk. The company raised its full-year guidance in May after first-quarter sales of its Wegovy weight loss pill came in ahead of expectations, offering a measure of relief after the company's Danish shares had shed roughly 40% of their value over the prior year. Copenhagen-listed Novo Nordisk stock had declined 7% year-to-date heading into Friday's session, according to CNBC.
Full results from the ZEUS trial will be presented at a scientific meeting later in 2026.
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