Safety, Tolerability, Pharmacodynamics, and Pharmacokinetics of MK-8666 in Participants With Type 2 Diabetes Mellitus (MK-8666-003)

Inclusion Criteria:

- If female, must be either postmenopausal or surgically sterile

- A Body Mass Index (BMI) ≥18 kg/m^2 to ≤40 kg/m^2, inclusive.

- A diagnosis of T2DM

- Drug naïve or is being treated with no more than 2 oral antihyperglycemic agents
(thiazolidenediones are excluded)

- Judged to be in good health except for T2DM

- Willing to follow a standard weight maintaining diet throughout the study

- A nonsmoker or has not used nicotine or nicotine-containing products for at least 3
months

Exclusion Criteria:

- A history of clinically significant endocrine (except T2DM), gastrointestinal,
cardiovascular, hematological, hepatic, immunological, renal, respiratory, or
genitourinary abnormalities or diseases

- A history of myositis or complaints including diffuse myalgias, muscle tenderness, or
weakness.

- A history of cancer (malignancy) excepting adequately treated non-melanomatous skin
carcinoma or carcinoma in situ of the cervix

- Has clinically unstable diabetic retinopathy, neuropathy, and/or clinical evidence of
gastroparesis (frequent nausea, bloating or vomiting, severe gastroesophageal reflux,
early satiety)

- A history of type 1 diabetes mellitus and/or history of ketoacidosis

- Taking a medication for a co-morbid condition that is not permitted during the study

- A history of significant multiple and/or severe allergies

- Positive for hepatitis B surface antigen, hepatitis C antibodies or human
immunodeficiency virus

- Had major surgery, donated or lost 1 unit of blood within 4 weeks prior to study
participation

- Participated in another investigational trial within 4 weeks prior to study
participation

- Consumes excessive amounts of alcoholic or caffeine-containing beverages

- A regular user of illicit drugs or a history of drug or alcohol abuse within the past
year