A Study of Tirzepatide in Participants With Type 2 Diabetes Mellitus (T2DM)

The Effect of Tirzepatide on α and β Cell Function and Insulin Sensitivity in Patients With Type 2 Diabetes Mellitus

This is a study for participants with type 2 diabetes mellitus. The main purpose of this study is to learn more about how tirzepatide, semaglutide and placebo affect the body's ability to respond to blood sugar levels after a meal. The study will last up to 40 weeks, including a 28-week treatment period.

Inclusion Criteria:

• Have T2DM for at least 6 months
• Treated with diet and exercise and stable dose(s) of metformin, with or without 1 additional stable dose of oral antihyperglycemia medication other than metformin, 3 months prior to study entry
• Have a hemoglobin A1c (HbA1c) value at screening of ≥7% and ≤ 9.5 % if on metformin only; or ≥6.5% and ≤9.0% if on metformin in combination with oral antihyperglycemia medications other than metformin
• Have a body mass index (BMI) between 25 and 45 kilograms per square meter (kg/m² ) inclusive, at screening; are of stable weight (±5%) >3 months prior to screening

Exclusion Criteria:

• Have a history of proliferative retinopathy or maculopathy as determined by the investigator based on a recent (<1.5 years) ophthalmologic examination
• Impaired renal estimated glomerular filtration rate (eGFR) <45 milliliters per minute per 1.73 square meters (mL/min/1.73 m²) calculated by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)
• Have a history or current cardiovascular, respiratory, hepatic, renal, GI,endocrine, hematological or neurological disorders capable of significantly altering the absorption, metabolism or elimination of drugs; of constituting a risk when taking the study drug; or of interfering with the interpretation of data