This study in China is open to adults who are at least 18 years old who are living with overweight or obesity. People with a body mass index (BMI) of 28 kg/m^2 or higher or 24 kg/m^2 or higher with at least 1 weight related problem can join the study. The main purpose of this study is to find out whether a medicine called survodutide helps people with overweight or obesity. 2 different doses of survodutide are tested in this study.

Participants are put into 3 groups by chance. Each participant has an equal chance of being in each group. 2 groups get different doses of survodutide. 1 group gets placebo. Participants get survodutide or placebo as injections under the skin once a week for about 19 months.

Placebo injections look like survodutide injections but do not contain any medicine.

Participants are in the study for about 21 months. During this time, there are 20 visits. 14 visits are in person at the study site. Where possible, 6 visits can be done by video call, or by phone in rare cases. During this time, doctors regularly measure participant's body weight. Results are compared between the survodutide groups and placebo group to see whether the treatment works. The doctors also regularly check participants' health and take note of any unwanted effects.

Inclusion Criteria:

1. Male or female, age ≥18 years at the time of signing informed consent.

2. Body mass index (BMI) ≥28 kg/m^2 at screening, OR BMI ≥24 kg/m^2 at screening with the presence of at least one of the following weight-related complications:

   • Hypertension (defined as repeated, i.e. at least 3 measurements in resting condition, systolic blood pressure (SBP) values of ≥140 mmHg and/or diastolic blood pressure (DBP) values of ≥90 mmHg in the absence of anti-hypertensive treatment, or intake of at least 1 anti-hypertensive drug to maintain a normotensive blood pressure)

   • Dyslipidaemia (defined as at least 1 lipid-lowering treatment required to maintain normal blood lipid levels, or low density lipoprotein (LDL) cholesterol ≥160 mg/dL (≥4.1 mmol/L), or triglycerides ≥150 mg/dL (≥1.7 mmol/L), or high density lipoprotein (HDL) cholesterol <40 mg/dL (<1.0 mmol/L) for men or HDL cholesterol <50 mg/dL (<1.3 mmol/L) for women)

   • Obstructive sleep apnoea

   • Cardiovascular disease (CVD) (e.g. heart failure (HF) with New York Heart Association (NYHA) functional class II-III, history of ischaemic or haemorrhagic stroke or cerebrovascular revascularisation procedure [e.g. carotid endarterectomy and/or stent], myocardial infarction (MI), coronary artery disease, or peripheral vascular disease)

   • Type 2 diabetes mellitus (T2DM) diagnosed at least 180 days prior to screening (glycosylated haemoglobin A1c (HbA1c) ≥6.5% (48 mmol/mol) and <10% (86 mmol/mol), and fasting plasma glucose (FPG) ≤11.1 mmol/L measured by the central laboratory at screening

     --- Currently treated with either: diet and exercise alone or stable treatment (for at least 3 months prior to screening) with metformin, sodium-glucose cotransporter-2 inhibitor (SGLT2i) inhibitor, acarbose, sulfonylurea, or glitazone as single agent therapy, or up to 3 anti-hyperglycaemia medications (metformin, SGLT2i, acarbose, sulfonylurea, or glitazone) according to local label

   • Non-alcoholic steatohepatitis (NASH), as assessed in medical records by histological liver assessment (within the last 6 months)

3. History of at least one self-reported unsuccessful dietary effort to lose body weight

4. Signed and dated written informed consent in accordance with International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use-Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial

5. Woman of childbearing potential (WOCBP) must be ready and able to use highly effective methods of birth control per ICH M3 (R2) that result in a low failure rate of less than 1% per year when used consistently and correctly. A list of contraception methods meeting these criteria and instructions on the duration of their use will be provided in the participant information.

Further inclusion criteria apply.

Exclusion Criteria:

(A) Obesity:

1. Body weight change (self-reported) >5% within 3 months before screening.
2. Treatment with any medication for the indication obesity within 3 months before screening.
3. Previous or planned (during the trial period) treatment for obesity with surgery or a weight loss device, or prior surgery of the GI tract that could interfere with body weight The following are allowed: (1) liposuction and/or abdominoplasty, if performed >1 year before screening, (2) lap banding, if the band has been removed >1 year before screening, (3) intragastric balloon, if the balloon has been removed >1 year before screening, (4) duodenal-jejunal bypass sleeve, if the sleeve has been removed >1 year before screening, (5) appendectomy, (6) simple hernia repair, or (7) cholecystectomy
4. Have obesity induced by other endocrinologic disorders (for example, Cushing Syndrome) or diagnosed monogenetic or syndromic forms of obesity (for example, melanocortin 4 receptor deficiency, leptin deficiency, or Prader Willi Syndrome) (B) Diabetes-related for participants with T2DM:
5. Treatment with any medication for the indication of T2DM other than stated in the inclusion criteria within 3 months before screening (i.e. insulin, amylin analogues, glucagon-like peptide-1 receptor (GLP- 1R)) agonists, GLP-1R agonist/insulin/glucose-dependent insulinotropic polypeptide (GIP) combinations, and dipeptidyl peptidase 4 inhibitor (DPP-4i))
6. New initiation of any other glucose-lowering investigational drug within 3 months prior to screening for this trial
7. Uncontrolled and potentially unstable diabetic retinopathy or maculopathy, verified by an eye examination within 3 months prior to screening or in the period between screening and randomisation Further exclusion criteria apply.

One year after the approval has been granted by major Regulatory Authorities and after the primary manuscript has been accepted for publication, or after termination of the development program.

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.