A Study of LY2605541 Versus Insulin Glargine on Blood Sugar

Comparison of the Effects of LY2605541 and Insulin Glargine on Endogenous Glucose Output and Peripheral Glucose Disposal in Healthy Subjects and Patients With Type 1 Diabetes Mellitus

LY2605541 is an investigational drug being developed for the treatment of diabetes mellitus. This study is designed to understand how the body handles the investigational drug, what effect this investigational drug has on the body, and how much should be given. This study will also measure how much of the investigational drug gets into the blood stream and how long it takes the body to get rid of it. The study has 2 parts: Part A will be conducted in healthy participants. Part B will be conducted in participants with type 1 diabetes mellitus (T1DM). This study will take approximately 10-14 days spread over 6-20 weeks, not including screening. Screening will be performed within 30 days of the start of the study.

Inclusion Criteria:

All Participants

• Are healthy males or participants with T1DM
• Have a screening body mass index (BMI) of 20.0-29.9 kilograms per square meter (kg/m^2)

Healthy Participants ONLY

• Are overtly healthy, as determined by medical history and physical examination
• Have a fasting blood glucose <108 milligrams/deciliter (mg/dL) (6.0 millimoles/liter [mmol/L]) at screening

Participants with T1DM ONLY

• Have a diagnosis of T1DM for at least 1 year based on medical history
• Have a screening c-peptide <0.5 nanograms/milliliter (ng/mL)
• Have a hemoglobin A1c (HbA1c) of 6.0 to 9.0% at screening
• Have had no episodes of severe hypoglycemia in the past 6 months

Exclusion Criteria:

All Participants

• Have a hemoglobin level <12.0 grams/deciliter (g/dL)
• Are currently a smoker, used tobacco products on a regular basis in the 6 months prior to screening, or are intending to smoke during the study

Healthy Participants ONLY

• Regular use or intended use of over-the counter or prescription medication within 7 and 14 days, respectively, prior to dosing (apart from vitamin/mineral supplements or occasional use of acetaminophen or ibuprofen).

Participants with T1DM ONLY

• Regular use or intended use of any over-the-counter or prescription medications or nutritional supplements that affect blood glucose or the body's sensitivity to insulin or that promote weight loss within 14 days prior to dosing
• Are receiving chronic (lasting longer than 14 consecutive days) systemic or inhaled glucocorticoid therapy (excluding topical, intra-articular, and intraocular preparations) or have received such therapy within the 4 weeks before dosing
• Require a total daily insulin dose exceeding 100 units (U)
• Have fasting triglycerides >400 mg/dL