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 <10% (<86 mmol/mol) as measured by the central laboratory at screening.
5. Currently treated for T2DM with either diet and exercise alone or stable treatment (for at least 3 months prior to screening) per treatment guidelines.
6. History of at least one self-reported unsuccessful dietary effort to lose body weight Further inclusion criteria apply.

Exclusion Criteria:

1. Body weight change (self-reported) of >5% within 3 months before screening.
2. Treatment with any medication for the indication obesity within 3 months before screening.
3. Treatment with any medication for indication of T2DM other than stated in the inclusion criteria and glucagon-like peptide-1 receptor (GLP-1R)-based agonists) and dipeptidyl peptidase 4 inhibitor [DPP-4il).
4. Known clinically significant gastric emptying abnormality (e.g., severe diabetic gastroparesis or gastric outlet obstruction).
5. History of either chronic or acute pancreatitis or elevation of serum lipase or amylase >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.](streamdown:incomplete-link)

Once the criteria in section 'time frame' are fulfilled, researchers can use the following link https:// www.mystudywindow.com/msw/datasharing to request access to the clinical study documents regarding this study, and upon a signed "Document Sharing Agreement". Furthermore, researchers can request access to the clinical study data, for this and other listed studies, after the submission of a research proposal and according to the terms outlined in the website.

After structured results have been posted, all regulatory activities are completed in the US and EU for the product and indication, and after the primary manuscript has been accepted for publication.

For study documents - upon signing of a 'Document Sharing Agreement'.For study data -1. after the submission and approval of the research proposal (checks will be performed by the sponsor and/or the independent review panel, including checking that the planned analysis does not compete with sponsor's publication plan); 2. and upon signing of a legal agreement.