The goal of this clinical trial is to learn if AT673 contributes to additional weight loss and glycemic control when given with semaglutide in participants with overweight/obesity and type 2 diabetes. The main questions it aims to answer are:
* To compare the effect on body weight of two doses of AT673 once-weekly versus matched placebo when concurrently administered with semaglutide once-weekly
* To evaluate the effect of AT673 on glycated hemoglobin (HbA1c)
* To compare the safety and tolerability of AT673 versus matched placebo when concurrently administered with semaglutide