A Single and Multiple Ascending Dose Trial Assessing Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of ZP6590 in Participants With Normal Weight, Overweight and Obesity

The goal of this clinical trial is to learn about the safety and tolerability of drug ZP6590 and to learn how the body processes the drug ZP6590 in adults. The main questions it aims to answer are: * Is the drug ZP6590 safe and well tolerated when administered as escalating single and multiple doses of the ZP6590? * How quickly and to what extent the administered investigational drug is absorbed and distributed, and how long it takes to be eliminated from the body? In the first Part of the study: Participants will: • Get a single ascending dose of the drug ZP6590 or placebo and will have an observation period of 4 weeks. In the second Part of the study: Participants will: • Get multiple dosages of the drug ZP6590 or placebo for 6 or 12 weeks followed by an observation period of 6 weeks after last dosing.

Inclusion Criteria: SAD-Part: * Male participant * Age between 18 and 55 years, both inclusive * Body Mass Index (BMI) between 20.0 and 29.9 kg/m\^2, both inclusive MAD-Part: * Male participant * Age between 18 and 60 years, both inclusive * Body Mass Index (BMI) between 27.0 and 39.9 kg/m\^2, both inclusive Exclusion Criteria: SAD-Part and MAD-Part: * Any clinically significant abnormal haematology, biochemistry, or urinalysis screening tests, as judged by the investigator * Treatment for weight management within 3 months before randomization in this trial