Key Highlights

• In the STEP Young study, 40.4% of children between ages 6 and 12 successfully dropped below obesity thresholds following 68 weeks of semaglutide treatment.
• Zero participants receiving placebo achieved comparable BMI improvements throughout the study period.
• The company discontinued two supplementary cardiovascular studies testing ziltivekimab following a monitoring board's determination of minimal success probability.
• The heart drug candidate had previously disappointed in a pivotal late-stage cardiovascular study during July.
• Shares of NVO declined 1.92% during trading.

Investors in Novo Nordisk faced contrasting developments on Monday, as encouraging findings from a childhood obesity study emerged simultaneously with announcements that the company was terminating two additional cardiovascular drug investigations.

Trading activity saw NVO shares decline 1.92% to $46.60, as investors processed both pieces of news. (Novo Nordisk A/S, NVO)

STEP Young: Semaglutide in Pediatric Obesity

The phase 3 STEP Young investigation evaluated weekly semaglutide administration in 165 pediatric patients between 6 and 12 years old diagnosed with obesity. Following a 68-week treatment period, 40.4% of children receiving the medication successfully reduced their BMI below obesity classification levels. In contrast, no participants assigned to the placebo arm achieved this outcome.

Every participant received comprehensive lifestyle intervention throughout the investigation, incorporating calorie-restricted nutrition plans and enhanced physical exercise regimens.

The study successfully achieved its principal objective, demonstrating significantly greater BMI reductions among semaglutide recipients versus those receiving placebo. Over 85% of enrolled children presented with severe class II or III obesity at baseline.

Pediatric participants were administered either 1.7 mg or 2.4 mg weekly semaglutide doses, determined by their initial body weight measurements.

Ania M. Jastreboff, Professor of Medicine and Pediatrics at Yale, characterized the findings as promising, particularly considering the substantial obesity severity observed among most study participants initially.

The drug's safety profile and tolerability aligned with observations from prior investigations involving adults and teenagers. Researchers identified no novel safety issues, and no concerns emerged regarding growth patterns or pubertal progression.

The results carry commercial significance because semaglutide, marketed as Wegovy, is already approved in the United States for obesity treatment in patients aged 12 and older, and positive data in younger children could support a future regulatory filing to extend that label to the 6-to-11 age group.

The pharmaceutical company intends to unveil comprehensive findings at ObesityWeek 2026 in Washington DC, scheduled for November 14 through 17.

Cardiovascular Program Faces Additional Challenges

The encouraging pediatric findings were counterbalanced by Novo's announcement that it was terminating two more clinical investigations of its investigational cardiovascular compound ziltivekimab.

Both studies were evaluating the medication in heart failure populations and received early termination after an independent data monitoring panel determined minimal probability that either investigation would yield outcomes differing from a previously unsuccessful trial.

During July, ziltivekimab had already demonstrated inability to decrease major adverse cardiovascular event risk—encompassing mortality, non-fatal myocardial infarction, and non-fatal cerebrovascular accidents—when compared against placebo in a late-stage investigation.

The consecutive disappointments represent a significant obstacle to Novo's strategy of expanding beyond its established obesity and diabetes portfolio, a diversification effort that has taken on added importance as rival drugmakers, most notably Eli Lilly with its tirzepatide-based products, compete aggressively in the GLP-1 market that Novo helped build.

This setback emerges following a similarly unsuccessful cardiovascular investigation from Novartis, whose experimental compound was also developed based on the identical inflammatory-disease theory that guided development of both therapeutics.

Future Outlook

A single ongoing ziltivekimab investigation remains active, evaluating the drug in individuals recovering from myocardial infarction. Findings are anticipated during the first half of 2027.

According to research published Friday, GLP-1 medication prescriptions for American children under age 12 have increased more than 300-fold since 2019, despite semaglutide lacking regulatory approval for this pediatric population. The STEP Young results therefore arrive amid an existing wave of off-label pediatric use, though any broader adoption in younger children would depend on regulatory review of the new data.