Investing.com -- Novo Nordisk (NYSE: NVO) shares dropped 10% Friday after the drugmaker revealed its experimental drug, ziltivekimab, failed to cut cardiovascular risk in a late-stage clinical trial.

The Danish company reported that its Phase 3 ZEUS trial showed no reduction in major adverse cardiovascular events (MACE) compared to a placebo in patients dealing with atherosclerotic cardiovascular disease (ASCVD), chronic kidney disease (CKD), and systemic inflammation. The study posted a hazard ratio of 0.99 (95% CI: 0.88 to 1.11).

While ziltivekimab successfully hit its biological targets—inhibiting the IL-6 pathway and delivering expected drops in free IL-6 and high-sensitivity C-reactive protein—that biological activity failed to lower actual cardiovascular risk.

Inside the ZEUS Trial

The double-blind, placebo-controlled study evaluated over 6,300 participants with ASCVD, CKD, and inflammation. Researchers tested a once-monthly 15 mg dose of ziltivekimab against a placebo to measure its ability to prevent MACE—defined as cardiovascular death, non-fatal heart attack, or non-fatal stroke.

"Despite not achieving the hoped-for MACE benefit, this study provides vital scientific evidence that will help inform our ongoing cardiovascular research," said Martin Holst Lange, Executive Vice President and Chief Scientific Officer at Novo Nordisk.

Safety & Next Steps

• Safety Profile: Overall rates of adverse and serious adverse events were similar between the ziltivekimab and placebo groups, with no difference in all-cause mortality. However, patients on ziltivekimab saw a higher rate of serious infections.

• Pipeline: Two other cardiovascular trials for ziltivekimab—focusing on heart failure and post-acute heart attack patients—will proceed as planned, with results expected in the first half of 2027.

• Financial Impact: Novo Nordisk confirmed the outcome won’t affect its previously announced 2026 adjusted operating profit outlook, though it will trigger a non-cash impairment charge in Q3 2026.

Wall Street Reaction: A "Negative" Blow to R&D Momentum

UBS analyst Matthew Weston called the trial outcome "NEGATIVE," noting that UBS estimates previously modeled 60% of ziltivekimab’s $3 billion peak sales and accounted for 1.7% of Novo Nordisk’s Net Present Value (NPV).

Weston expects the market reaction to be 2–3x larger than the pure NPV impact, pointing to two key headwinds:

• Compounding R&D Pressure: The failure adds to recent research and development hurdles.

• Growth Pillar Bottleneck: It limits Novo Nordisk’s potential to establish cardiovascular therapies as a major secondary growth engine alongside its metabolic portfolio.

Mizuho analyst Jared Holz called the early look at the trial a "disappointment" that could derail sentiment around Novo’s broader pipeline beyond weight-loss drugs.

• Holz noted that while investors were becoming more bullish on the IL-6 program’s efficacy and concerned about safety/tolerability, the outcome was the exact opposite: safety looked fine, but the lack of statistically significant efficacy renders it a dead point for shareholders today.

• While additional IL-6 cardiovascular trials continue, Holz expects Wall Street to heavily discount those programs over the short term until readouts approach a year from now.

• The setback could put additional pressure on Novo Nordisk management to engage in more meaningful M&A to diversify and broaden its therapeutic capabilities beyond ancillary obesity-related assets.

• Industry comps GLUE and BIOA both came under pre-market pressure following the news. Holz noted it will take time for both to regroup, though buying on weak days often proves profitable.

Despite the noise, Holz highlighted that Novo sets up well heading into Q3 EPS next Wednesday, driven by the blockbuster launch of the Wegovy pill—one of the best drug launches of all time—which could spark buying on stock weakness today.