Novo Nordisk's Double Blow: A Failed Heart Drug and a Mounting Legal Challenge

Novo Nordisk's stock drops 8.5% after Phase 3 ZEUS trial misses primary endpoint, while a US court allows part of a securities class action over CagriSema disclosures.

The Danish pharmaceutical giant's ambitions beyond its blockbuster weight-loss and diabetes franchise suffered a significant setback on Friday, as investors digested both a disappointing clinical readout and an unfavorable legal development in the United States.

Shares in Novo Nordisk tumbled 8.48 percent to close at EUR 40.90 in German trading, marking the steepest one-day decline in nearly five months. The weekly loss stood at 4.63 percent, extending a bruising stretch for a company that has seen its stock fall roughly seven percent since the start of the year.

A Biological Success That Failed Clinically

The immediate trigger was the failure of the Phase 3 ZEUS trial, which tested the cardiovascular drug Ziltivekimab in more than 6,300 patients suffering from atherosclerotic cardiovascular disease, chronic kidney disease, and systemic inflammation (defined as hsCRP of 2 mg/l or higher). Patients received monthly 15-milligram doses of the drug, which was designed to block the inflammatory signaling molecule IL-6.

The drug did exactly what it was supposed to do biologically: it reliably suppressed both IL-6 and hsCRP levels. Yet the primary endpoint—a statistically significant reduction in major adverse cardiovascular events, including cardiovascular death, non-fatal heart attacks, and non-fatal strokes—was missed. The hazard ratio of 0.99 meant the drug performed essentially no better than placebo. Compounding the disappointment, serious infections occurred more frequently in the treatment arm, while overall mortality showed no difference between groups.

Novo Nordisk said it would record a non-cash impairment charge in the third quarter related to the program, though management reiterated that its full-year 2026 guidance remains unchanged. The drug, acquired through the 2020 purchase of Corvidia Therapeutics for USD 725 million plus potential milestone payments of up to USD 2.1 billion, was meant to give the company a credible growth engine beyond its core GLP-1 business.

Chief Scientific Officer Martin Holst Lange told CNBC that the outcome does not alter the company's strategic commitment to cardiology. Two additional Ziltivekimab studies—HERMES, examining the drug in heart failure, and ARTEMIS, testing it in acute myocardial infarction—remain ongoing, with results expected in the first half of 2027.

Legal Pressure Mounts Over CagriSema Disclosures

The clinical disappointment arrived alongside a legal setback that has been building for weeks. A federal judge in New Jersey ruled this week that Novo Nordisk must face part of a securities fraud class action related to its CagriSema program—the combination therapy pairing semaglutide with the amylin analogue cagrilintide.

Shareholders allege that the company and certain executives made misleading statements about the REDEFINE-1 trial protocol. Specifically, plaintiffs claim Novo Nordisk failed to disclose that participants were permitted to adjust their dosing when experiencing tolerability issues, which they argue obscured the drug's true side-effect profile. Judge Robert Kirsch dismissed some claims tied to specific public statements but allowed the core allegations regarding protocol transparency to proceed.

Technical Support and a Divided Analyst Camp

The closing price of EUR 40.90 lands almost precisely on the 50-day moving average, while the 200-day average sits just below at EUR 40.35. That means the stock is still 1.35 percent above its longer-term trend line—a level that technical analysts will be watching closely as a signal for the medium-term trend. The gap to the year's high of EUR 54.86 remains roughly a quarter.

Wall Street's reaction was notably split. Analysts at Jefferies and Citi characterized Friday's sell-off as overdone, even as they acknowledged the strategic damage. The market value erased on Friday—north of USD 30 billion—struck many observers as disproportionate to the revenue contribution the failed drug would have delivered in the near term. The consensus rating sits at "Hold" with a price target of approximately USD 47.

The episode has sharpened the central question hanging over the stock: can the GLP-1 franchise—Ozempic and Wegovy—continue to carry the valuation on its own? Critics point to the company's heavy dependence on that segment, while supporters note that the pipeline setback does nothing to diminish the commercial momentum of the core products.

What Comes Next

The near-term catalyst is the second-quarter earnings report due Wednesday, August 5. Analysts expect earnings per share of USD 0.81, a 16.5 percent decline year over year. Other forecasts project revenue of DKK 71.5 billion and EPS of DKK 5.04, both below prior-year levels. Management's commentary on Wegovy and Ozempic sales, the performance of the newly launched oral Wegovy pill, and production capacity expansion will be closely scrutinized.

The company has had some recent wins to point to: the oral Wegovy pill received EU approval in mid-July, along with a higher-dose 7.2-milligram version. Late last month, Novo Nordisk also filed a lawsuit against Eli Lilly over allegedly misleading advertising for its GLP-1 products. A share buyback program of up to USD 2.3 billion is underway, with roughly USD 1.10 billion deployed as of July 24.

Between the ZEUS failure, the CagriSema litigation, and the upcoming earnings report, the coming weeks will test whether Novo Nordisk's core story remains intact—or whether the market's patience with the company's diversification strategy is wearing thin.