This is a Phase II, randomised, parallel-group, double-blind, placebo-controlled, multi-centre study to assess the efficacy, safety, and tolerability of AZD6234 compared with placebo, given once weekly as a subcutaneous (SC) injection, in adults living with overweight or obesity and type 2 diabetes who are on a stable dose of GLP-1 RA. The study is being conducted across sites in the USA to evaluate the efficacy, safety, and tolerability of AZD6234 in adults with overweight or obesity and type 2 diabetes on stable GLP-1 RA therapy. A total of 64 Participants, aged 18-75 with a BMI ≥ 27 kg/m², will be randomized to receive weekly subcutaneous injections of either AZD6234 or a placebo, alongside their current GLP-1 RA medication. The study involves a screening period and a treatment and follow-up period.