Ertugliflozin and Sitagliptin Co-administration Factorial Study (MK-8835-005)

This study will include a 1-week screening period; an up to 12-week metformin titration/dose
stabilization period; a 2-week single-blind placebo run-in period; a 52-week (26-week Phase
A and (26-week Phase B) double-blind treatment period and a post-treatment telephone contact
14 days after the last dose of study medication.

Inclusion Criteria:

- Type 2 diabetes mellitus as per American Diabetes Association guidelines

- On metformin monotherapy (>=1500 mg/day) for >=8 weeks with a Visit 1/Screening A1C
>=7.5% and <=11.0% (>=58 mmol/mol and <=97 mmol/mol) OR On metformin monotherapy
(>=1500 mg/day) for <8 weeks with a Visit 1/Screening A1C >=7.5% and <=11.0% (>=58
mmol/mol and <=97 mmol/mol) OR On metformin monotherapy <1500 mg/day with a Visit
1/Screening A1C >=8.0% and <=11.5% (>=64 mmol/mol and <=102 mmol/mol)

- Body mass index (BMI) >=18.0 kg/m^2

- Male or female not of reproductive potential

- Female of reproductive potential who agrees to remain abstinent from heterosexual
activity or to use 2 acceptable combinations of contraception

Exclusion Criteria:

- History of type 1 diabetes mellitus or ketoacidosis

- History of other specific types of diabetes (e.g., genetic syndromes, secondary
pancreatic diabetes, diabetes due to endocrinopathies, drug- or chemical-induced, and
post-organ transplant

- A known hypersensitivity or intolerance to any sodium glucose co-transporter (SGLT2)
inhibitor or sitagliptin

- Has been treated with any of the following agents within 12 weeks of study start or
during the pre-randomization period: Insulin of any type (except for short-term use
[i.e., <=7 days] during concomitant illness or other stress), other injectable
anti-hyperglycemic agents (e.g., pramlintide, exenatide, liraglutide), pioglitazone
or rosiglitazone, other sodium glucose co-transporter 2 (SGLT2) inhibitors, alpha
glucosidase inhibitors or meglitinides, dipeptidyl-peptidase 4 inhibitor (DPP-4
inhibitor), sulfonylureas (SUs), bromocriptine (Cycloset™), colesevelam (Welchol™),
any other AHA with the exception of the protocol-approved agents

- Is on a weight-loss program or weight-loss medication or other medication associated
with weight changes and is not weight stable prior to study start

- Has undergone bariatric surgery within the past 12 months or >12 months and is not
weight stable prior to study start

- A history of myocardial infarction, unstable angina, arterial revascularization,
stroke, transient ischemic attack, or New York Heart Association (NYHA) functional
class III-IV heart failure within 3 months of study start

- Active, obstructive uropathy or indwelling urinary catheter

- History of malignancy <=5 years prior to study start, except for adequately treated
basal cell or squamous cell skin cancer or in situ cervical cancer

- A known history of human immunodeficiency virus (HIV)

- A blood dyscrasia or any disorder causing hemolysis or unstable red blood cells, or a
clinically important hematological disorder (e.g. aplastic anemia, myeloproliferative
or myelodysplastic syndromes, thrombocytopenia)

- A medical history of active liver disease (other than non-alcoholic hepatic
steatosis), including chronic active hepatitis B or C, primary biliary cirrhosis, or
symptomatic gallbladder disease

- Any clinically significant malabsorption condition

- Current treatment for hyperthyroidism

- On thyroid replacement therapy and not on a stable dose for at least 6 weeks prior
study start

- On a previous clinical study with ertugliflozin

- eGFR (using the 4-variable Modification of Diet in Renal Disease Study Equation
(MDRD) equation) <60 mL/min/1.73 m^2

- Serum creatinine >= 1.3 mg/dL (115 µmol/L) for males and >= 1.2 mg/dL (106 µmol/L)
for females

- Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2 times upper
limit of normal

- Hemoglobin <12 g/dL (120 g/L) for males and <11 g/dL (110 g/L) for females.

- Participated in other studies involving investigational drug(s) 30 days prior to
study start

- Surgical procedure within 6 weeks prior to study start or major surgery planned
during the trial

- Positive urine pregnancy test

- Pregnant or breast-feeding, or planning to conceive during the trial, including 14
days following the last dose of study medication

- Planning to undergo hormonal therapy in preparation for egg donation during the
trial, including 14 days following the last dose of study medication

- Routinely consumes >2 alcoholic drinks per day or >14 alcoholic drinks per week or
engages in binge drinking

- Donated blood or blood products within 6 weeks of study start