A Study of LY2189265 and Sitagliptin in Participants With Type 2 Diabetes

Inclusion Criteria

• are males or females, diagnosed with T2DM (Type 2 Diabetes Mellitus) for ≥3 months prior to screening
• male participants with female partners of child-bearing potential, or partners who are pregnant or breastfeeding, agree to use a reliable method of contraception from the time of the first dose until 3 months after the last dose of investigational product, as determined by the investigator. The method may be one of the following:
• condom with spermicidal agent
• male participant sterilization
• true abstinence (which is in line with the participant's usual lifestyle choice; withdrawal or calendar methods are not considered acceptable)
• female participants not of child-bearing potential (that is, are postmenopausal or permanently sterilized [such as, tubal occlusion, hysterectomy, bilateral salpingectomy]). Such participants will not be required to use contraception but must test negative for pregnancy at the time of enrollment. Postmenopausal is defined as at least 1 year post cessation of menses (without an alternative medical cause) or at least 1 year of spontaneous amenorrhea, with follicle stimulating hormone (FSH) ≥40 milli-international units/milliliter (mIU/mL)
• female participants who have undergone sterilization by tubal ligation: agree to use a condom in conjunction with spermicidal gel, foam, cream, film or suppository from the time of screening until 3 months after the last dose of investigational product. Such participants must also test negative for pregnancy at the time of enrollment
• have a body mass index (BMI) of between 23.0 and 40.0 kilograms/meter squared (kg/m^2), inclusive, at the time of screening
• have T2DM controlled with diet and exercise alone, or are on a stable dose of metformin Immediate Release (IR) for at least 4 weeks prior to screening, or are on metformin Extended Release (ER) and are capable/willing to be switched onto metformin IR or washed out prior to the first dose of investigational product, or are on sulfonylureas, acarbose (or other disaccharidase inhibitors), thiazolidinediones, or meglitinides and are capable/willing to be washed out prior to the first dose of investigational product
• have a fasting blood glucose value at screening ≤15.3 millimoles/liter (mmol/L) (275 milligrams/deciliter [mg/dL])
• have a glycosylated hemoglobin A1c (HbA1c) value at screening (or within 4 weeks prior to screening) of 6.5% to 10%
• have clinical laboratory test results within normal reference range for the population or within normal reference range for the investigator site, or results with acceptable deviations that are judged to be not clinically significant by the investigator. Abnormalities of serum glucose, serum lipids, urinary glucose, and urinary protein consistent with T2DM are acceptable.
• have creatinine clearance (CrCl) of greater than 50 milliliters/minute (mL/min) at screening estimated by the Cockcroft-Gault formula
• have venous access sufficient to allow for blood sampling as per the protocol
• are reliable and willing to make themselves available for the duration of the study and are willing to follow study procedures

Exclusion Criteria

• are currently enrolled in, have completed or discontinued within the last 30 days from, a clinical trial involving an investigational product, or are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study
• have known allergies to glucagon-like-peptide 1 (GLP-1)-related compounds, including LY2189265 or to sitagliptin-related compounds or any components of either formulation
• are persons who have previously completed or withdrawn from this study or any other study investigating LY2189265 in the 3 months prior to screening or have received glucagon-like peptides or incretin mimetics in the 3 months prior to screening
• have taken insulin, chlorpropamide, or alpha-glucosidase inhibitors within 30 days prior to screening
• have an abnor