Novo Nordisk's CagriSema reaches primary completion date in head-to-head trial against tirzepatide

REDEFINE 4, Novo Nordisk's phase 3 trial of its investigational obesity drug CagriSema against tirzepatide, reached its primary completion date on December 8, 2025, according to the study's registry listing ^[1]. The trial enrolled 809 participants and ran for 84 weeks ^[1].

What the trial did

The study is registered on ClinicalTrials.gov as NCT06131437 ^[1]. The registry title describes it as a research study to see how well CagriSema compared to tirzepatide helps people with obesity lose weight ^[1]. Participants were assigned to one of the two drugs for 84 weeks ^[1].

The trial was open-label, meaning participants and their investigators knew which medicine each person was receiving rather than being kept unaware of the assignment ^[1]. The listing does not describe a placebo group ^[1].

For context on the molecules, tirzepatide is the active ingredient in Mounjaro and Zepbound, and semaglutide is the active ingredient in Ozempic, Wegovy and Rybelsus. CagriSema is an investigational combination product and is not an approved medicine in the United States; tirzepatide and semaglutide are.

Results are not yet public

The registry entry does not contain results ^[1]. No average weight-loss percentages, no measure of how many participants reached a given weight-loss threshold, and no statistical comparison between the two drugs has been posted ^[1]. Whether the trial met its goals has not been disclosed in the listing ^[1].

Under the reporting rules described in the same registry record, sponsors of applicable clinical trials generally must submit results information after a study's primary completion date, but a certification or extension request can delay that posting by up to two years ^[1]. That means the public registry may not show REDEFINE 4 results until well after December 2026 ^[1].

Novo Nordisk has not announced a date for releasing topline findings.

Why it matters for patients

People weighing obesity treatments have mostly had to compare drugs studied in separate trials, where differences in participants, dose schedules and study design make direct comparison difficult. A head-to-head trial uses one protocol, one enrollment period and one set of measurements for both drugs, which is the kind of evidence that can support a more direct comparison. Until REDEFINE 4 results are released, that comparison does not exist in public form.

One design detail is worth keeping in mind when results do appear: because the trial was open-label, participants and their clinicians knew which drug was being used ^[1]. Open-label results still count, but researchers generally treat them differently from blinded results when judging how much of an effect comes from the drug itself.

CagriSema is not currently available outside clinical research, so this trial does not change what a patient can be prescribed today. It may, however, shape what doctors and patients are able to compare if the drug is later approved.

What happens next

Results for REDEFINE 4 are due to the public registry on a schedule set by federal reporting rules, which allow extensions of up to two years beyond the primary completion date ^[1]. That places the earliest expected posting around late 2026 and a later posting into 2027 ^[1].

No date has been announced for a medical journal publication, a conference presentation or any regulatory filing based on REDEFINE 4. It has also not been reported whether the trial's 809 participants included people with type 2 diabetes or only people with obesity without diabetes ^[1].