A Study to Test Whether Survodutide (BI 456906) Helps People Living With Overweight or Obesity Who Also Have Diabetes to Lose Weight

This study is open to adults who are at least 18 years old and have a body mass index of 27 kg/m² or more. People can take part if they have type 2 diabetes and if they are currently being treated only with diet and exercise or with specific diabetes medications. Only people who have previously not managed to lose weight by changing their diet can participate. The purpose of this study is to find out whether a medicine called survodutide (BI 456906) helps people living with overweight or obesity who also have diabetes to lose weight. Participants are divided into 3 groups by chance, like drawing names from a hat. 2 groups get different doses of survodutide and 1 group gets placebo. Placebo looks like survodutide but does not contain any medicine. Every participant has a 2 in 3 chance of getting survodutide. Participants inject survodutide or placebo under their skin once a week for about one and a half years. In addition to the study medicine, all participants receive counselling to make changes to their diet and to exercise regularly. Participants are in the study for about 1 year and 7 months. During this time, it is planned that participants visit the study site up to 14 times and receive 6 phone calls by the site staff. The doctors check participants' health and take note of any unwanted effects. The study staff also regularly measure participants' body weight. The results are compared between the groups to see whether the treatment works.

Inclusion Criteria: 1. Male or female, age ≥18 years at the time of signing informed consent, and at least the legal age of consent in countries where it is \>18 years. 2. Body mass index (BMI) ≥27 kg/m\^2 at screening. 3. Diagnosed with Type 2 diabetes mellitus (T2DM) (defined as Glycosylated haemoglobin A1c (HbA1c) ≥6.5% \[≥48 mmol/mol\]) at least 180 days prior to screening. 4. HbA1c ≥6.5% (≥48 mmol/mol) and \2x upper limit of normal (ULN)) as measured by the central laboratory at screening. 6. Personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN 2). Further exclusion criteria apply.