A Study to Learn About the Study Medicine (PF-08653944) in People With Obesity or Overweight and Type 2 Diabetes (T2D)

The purpose of this clinical study is to learn about the safety and effects of the study medicine to help adults with obesity or overweight and type 2 diabetes lose weight. Being overweight or obese means carrying too much body weight. Type 2 diabetes is a condition where there is too much sugar in the blood. The study medicine is given by a shot under the skin in the belly area. The participants will be trained to do this at home once every week. About 660 out of 1000 adults will also receive the study medicine and about 330 out of 1000 adults will receive placebo. A placebo does not have any medicine in it but looks just like the medicine being studied. The investigators will compare the experiences of people receiving the study medicine to those of the people who do not. This will help us assess if the study medicine is safe and effective. People will take part in this study for about 21 months. During this time, they will have about 14 study visits at the site and 5 over the phone.

Inclusion Criteria: * Provision of signed and dated informed consent form (ICF) * Male or female adults, aged ≥18 years * Have a BMI at Screening of ≥27.0 kg/m2 * Have T2DM for at least 6 months before Screening based on participant reported history or documentation of the disease diagnostic criteria * Have HbA1c value between ≥6.5% (48 mmol/mol) and ≤10.0% (86.0 mmol/mol) at Screening with stable therapy for at least 90 days prior to Screening/Visit 1. T2DM may be treated with: --Diet and exercise alone or in combination with: Any oral antidiabetic therapy per local labeling EXCEPT DPP-4 inhibitors. Participant may NOT be on GLP-1 agonists or insulin * Participants must be motivated and willing to: * Self-inject study medication (or be aided by caregiver if needed), * Perform finger-stick glucose monitoring as required. * Have a history of at least 1 self-reported unsuccessful dietary effort to lose body weight. Exclusion Criteria: * Female who is breastfeeding, or who is pregnant * Unwilling or unable to follow contraceptive requirements * Diagnosis of Type 1 diabetes, or any other types of diabetes except T2DM. * Severe hypoglycemia and/or hypoglycemia unawareness within the 6 months prior to Screening * Poorly controlled hypertension * Have a prior or planned surgical treatment for obesity (excluding liposuction or abdominoplasty if performed \>1 year prior to screening) * Have taken within 3 months prior to randomization, medications (prescribed or over-the counter) intended to promote weight loss * Are receiving or have received within 3 months prior to screening chronic (\>2 weeks or 14 days) systemic glucocorticoid therapy