Novo Nordisk Shares Plunge After a Key Trial Fails. Should Investors Buy the Dip?

Shares of Novo Nordisk (NYSE:NVO) dropped 9.4% today after the Danish drugmaker announced that its experimental heart drug ziltivekimab failed a critical Stage 3 clinical trial. The trial, nicknamed “Zeus,” was the first of three late-stage trials for ziltivekimab to announce results; two other trials, named “Hermes” and “Artemis,” are expected to conclude in the first half of 2027.

But is today’s drop a buying opportunity? Here’s what investors need to know.

Image source: Getty Images.

Results but no benefits

Ziltivekimab is a once-monthly injection that inhibits the interleukin-6 (IL-6) protein. When it binds to its receptors, IL-6 can trigger chronic inflammation and the release of C-reactive protein from the liver.

The Zeus trial was a double-blind, placebo-controlled trial that tested 6,300 people with atherosclerotic cardiovascular disease (ASCVD), chronic kidney disease (CKD), and inflammation. They received a once-monthly shot of ziltivekimab to see if it would reduce their risk of major adverse cardiovascular events (MACE) like heart attacks and strokes.

The study found that ziltivekimab was effective in lowering levels of free IL-6 and C-reactive protein in patients' bloodstreams, indicating success in reducing inflammation. Unfortunately, those reductions didn’t translate into a lowered risk of MACE in the target population. Worse, because inflammation is the body’s response to infections, a higher proportion of people treated with ziltivekimab experienced serious infections compared with those who received a placebo. However, no difference in mortality was observed.

The two ongoing ziltivekimab trials, Hermes and Artemis, are similarly structured, except that instead of testing ziltivekimab in people with ASCVD, CKD, and inflammation, the company is testing it in people with heart failure (Hermes) and those who have experienced an acute heart attack (Artemis).

Image source: Novo Nordisk.

The fallout

According to the company, the failure won’t affect Novo Nordisk’s adjusted operating profit outlook for 2026, although the company will incur a non-cash impairment charge in Q3. The loss is mostly in potential future income.

Given the success of Novo Nordisk’s semaglutide injections, Ozempic and Wegovy, you might not expect a trial of an experimental cardiovascular drug to have such an outsize impact on the stock.

Investors had been hoping that ziltivekimab would expand the company’s reach beyond diabetes and weight-loss drugs. The clinical trial failure is a big letdown because the lack of a MACE reduction among patients in the Zeus trial suggests such a reduction may be less likely in the Hermes and Artemis trial populations as well.

Whether to buy the dip

Although today’s share price drop was big, it didn’t come close to the company’s back-to-back 17% share price declines in February.

The first of those came after management issued a bleak 2026 outlook that predicted drops in revenue and operating profit of up to 13% for the year, and the second came after Novo Nordisk’s next-generation obesity drug, CagriSema, underperformed Eli Lilly’s (NYSE:LLY) rival treatment, tirzepatide, in a head-to-head trial.

That said, the market for GLP-1 obesity treatments is massive and growing quickly, reaching an expected $120 billion by 2030. In fact, Novo Nordisk upped its full-year guidance in May on the back of strong Wegovy sales in Q1.

While it’s preferable for a drugmaker to have multiple blockbuster drugs in its arsenal, Novo Nordisk still has plenty of growth opportunities from semaglutide alone. The company’s shares are currently trading at a price-to-earnings ratio of just 11, near its all-time low.

For those who have been waiting to buy into the GLP-1 treatment market, now looks like an excellent opportunity to do so.

John Bromels has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Eli Lilly and Novo Nordisk. The Motley Fool has a disclosure policy.