A Research Study to Look Into the Long-term Effect on Weight Loss of CagriSema in People With Obesity

Long-term Efficacy and Safety of Cagrilintide s.c. 2.4 mg in Combination With Semaglutide s.c. 2.4 mg (CagriSema 2.4 mg/2.4 mg) Once Weekly Versus Placebo in Participants With Obesity

This study will look at how well CagriSema helps people with obesity lose weight compared to a "dummy medicine". CagriSema is a new medicine developed by Novo Nordisk. CagriSema cannot yet be prescribed by doctors. The study has two parts: First part is called the main phase and will last for 2 years, and second part is called the extension phase and will last for 1 year. In the main phase participants will either get CagriSema or "dummy medicine". Which treatment participants get is decided by chance and is not known by participants or the study doctor. In the extension phase participants will get either CagriSema or slowly reduce participants dose of CagriSema if participants had CagriSema in the main phase. Which treatment participants get is decided by chance and is not known by participants or the study doctor in both phases. If participants had "dummy medicine" in the main phase, participants will get CagriSema in the extension phase. Like all medicines, the study medicine may have side effects.

Inclusion criteria:

• Male or female.
• Age above or equal to 18 years at the time of signing informed consent.
• Body mass index (BMI) greater than or equal to (>=) 35.0 kilograms per meter square (kg/m^2).

Exclusion criteria:

• Glycated haemoglobin (HbA1c) >= 6.5 percent (48 millimoles per mole [mmol/mol]) as measured by the central laboratory at screening.
• History of type 1 or type 2 diabetes.