A Study to Evaluate Effect of AZD6234 as an Adjunct to Incretin-based Therapies in Adult Participants With Obesity or Overweight With Weight-related Comorbidity With or Without Type 2 Diabetes Mellitus

The study will evaluate how well AZD6234 works and how safe it is in adults with excess weight or obesity. Efficacy of AZD6234 will be compared to placebo in percent body weight change from baseline at 68 weeks of treatment.

Inclusion Criteria: * Males \& females (inclusive of all gender identities) age ≥18 years * BMI ≥ 30 kg/m2 OR BMI ≥ 27 kg/m2 with at least one of the following weight-related comorbidities (treated or untreated): hypertension, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease, heart failure, chronic kidney disease, metabolic dysfunction associated steatotic liver disease, osteoarthritis of the knee, or stress urinary incontinence * For participants with T2DM only: * Diagnosed with T2DM ≥ 90 days prior to Screening * HbA1c value at Screening of ≥6.0% (42 mmol/mol) and ≤9.0% (75 mmol/mol) managed with diet and exercise alone or with a stable dose of any oral glycaemic-lowering agent and/or incretin-based medication * Receiving a stable dose of incretin- based medications at a dose level that is sufficient for chronic weight management for at least 3 months prior to Screening and Randomisation. * Stable body weight (≤ 3% body weight change) for at least 3 months prior to Randomisation * History of at least one self-reported unsuccessful attempt to lose body weight in their lifetime Exclusion Criteria: * Obesity primarily caused by other endocrine disorders * Type 1 diabetes mellitus * Significant hepatobiliary disease and/or any of the following results at Screening: * ALT ≥ 3.0 × ULN * AST ≥ 3.0 × ULN * TBL \> 1.5 × ULN (except for cases of known Gilbert's Syndrome) * Use of insulin therapy for T2DM within 3 months prior to screening