NVO Halts Two More Ziltivekimab IL-6 Phase 3 Trials

Novo Nordisk (NVO) halted two more Phase 3 trials of its IL-6 inhibitor ziltivekimab after an independent data monitoring committee concluded neither was likely to produce a different result from the ZEUS cardiovascular outcomes trial that failed in July. The stock traded at $44.56, largely flat on the news.

HERMES (NCT05636176) measured time to first heart failure event including cardiovascular death and hospitalizations in patients with heart failure and elevated inflammation. ATHENA (NCT06200207) assessed quality-of-life endpoints in the same population. Investigators were notified on September 4 that both would end early, with patients completing a three-month follow-up visit.

The company is not walking away entirely. The ARTEMIS trial, evaluating ziltivekimab as an acute treatment immediately after myocardial infarction, continues with data expected in the first half of 2027. That study targets a different clinical window where the IL-6 hypothesis may still hold: the inflammatory cascade after a heart attack differs from the chronic low-grade inflammation that drives atherosclerosis, the mechanism ZEUS targeted. With ZEUS, HERMES, and ATHENA all negative or futile, the program has narrowed to this single remaining readout. ARTEMIS enrolled roughly 4,000 patients, a scale that gives the trial adequate power to detect a clinically meaningful benefit if one exists.

Ziltivekimab is a once-monthly subcutaneous monoclonal antibody that neutralizes IL-6, a key driver of the inflammatory response implicated in both atherosclerosis progression and post-MI cardiac remodeling. Novo acquired the drug through its $725 million Corvidia Therapeutics buyout in 2020, betting that targeting inflammation could build a cardiovascular franchise beyond semaglutide. That thesis has now failed in three separate trials across chronic cardiovascular disease. The broader anti-inflammatory cardiology field has a poor track record: canakinumab (anti-IL-1β) showed modest benefit in the CANTOS trial but never secured a cardiovascular label, and other IL-6 inhibitors have also disappointed in cardiovascular settings.

The next catalyst for Novo’s pipeline diversification is the Phase 3 CagriSema REDEFINE-2 obesity readout, expected by year-end 2026. Novo originally structured the Corvidia deal with up to $2.1 billion in milestones, but with three of four cardiovascular trials now failed, the remaining commercial value of ziltivekimab hinges entirely on ARTEMIS. The 2020 acquisition was a $725 million upfront bet during a period when Novo was actively looking to reduce its dependence on diabetes and obesity revenue, a dependency that has only deepened since. For more context on the ZEUS failure that preceded these halts, see the July 31 coverage of the ZEUS Phase 3 miss. The risk is that ARTEMIS fails too, writing off the rest of the $2.1 billion in milestone value and ending the program.

Source: Novo Nordisk halts HERMES and ATHENA (Endpoints News) · ClinicalTrials.gov: HERMES

What It Means for the Trade

A flat stock on two Phase 3 halts tells you the market had already written off ziltivekimab after ZEUS failed in July. HERMES and ATHENA did not break new ground — they confirmed that chronic cardiovascular inflammation is the wrong battlefield for this molecule. For the Corvidia deal, the practical read is that most of the up-to-$2.1 billion milestone structure is now dead value, and the $725 million upfront is a sunk lesson in cardio-inflammatory risk. None of this moves NVO’s investment case, which is CagriSema and the REDEFINE-2 readout by year-end. Anyone holding NVO for pipeline diversification should note that diversification just got narrower, not wider.

Program Context

ARTEMIS is a legitimately different experiment, not a Hail Mary in disguise. The inflammatory cascade in the days and weeks after a myocardial infarction — necrotic tissue, remodeling stress, acute cytokine surge — is biologically distinct from the chronic low-grade inflammation that drives atherosclerotic plaque, which is what ZEUS, HERMES, and ATHENA all tested. Roughly 4,000 patients gives the trial real power. But the class base rate is brutal: canakinumab showed a modest CANTOS benefit and still never earned a cardiovascular label, and IL-6 inhibition has repeatedly disappointed in this territory. An estimated 2027 first-half readout makes ARTEMIS a free option on the program, nothing more. A single positive post-MI trial can still be argued as niche rather than franchise-making.

Risks and What Could Go Wrong

1. ARTEMIS misses. This is the base case given three consecutive failures and the field’s track record. The program ends, the remaining milestones are written off, and Novo’s cardiovascular ambitions revert to semaglutide’s outcomes data.
2. ARTEMIS succeeds narrowly. A post-MI label in a field crowded with cheap statins and antiplatelets may not support premium pricing, making the win more optical than economic.
3. Continued concentration. Every failed diversification bet deepens Novo’s dependence on obesity and diabetes revenue just as that franchise faces pricing pressure and competition. The strategic risk is the dependency, not the trial.