A Research Study to Compare Two Different Versions of Injectable Cagrilintide and Placebo in People With Excess Body Weight

Inclusion criteria: * Informed consent obtained before any study-related activities. Study-related activities are any procedures that are carried out as part of the study, including activities to determine suitability for the study. * Male or female (sex assigned at birth, inclusive of all gender identities). * Age 18 years or above at the time of signing the informed consent. * Body mass index (BMI) greater than or equal to (\>=) 30.0 kilograms per square meter (kg/m\^2), or BMI \>= 27.0 kg/m\^2 with the presence of at least one weight related comorbidity including, but not limited to, hypertension, dyslipidaemia, obstructive sleep apnoea or cardiovascular disease. Exclusion criteria: * History of Type 1 Diabetes (T1D) or Type 2 Diabetes (T2D). * Previous dosing of marketed or non-marketed amylin-based compounds. * Treatment, or intention to initiate treatment, with any medication prescribed for the indication of weight management within 180 days before screening.