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

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% (>=58mmol/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 heterosexualactivity 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, secondarypancreatic diabetes, diabetes due to endocrinopathies, drug- or chemical-induced, andpost-organ transplant

• A known hypersensitivity or intolerance to any sodium glucose co-transporter 2 (SGLT2)inhibitor or sitagliptin

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

• Is on a weight-loss program or weight-loss medication or other medication associatedwith 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 notweight stable prior to study start

• A history of myocardial infarction, unstable angina, arterial revascularization,stroke, transient ischemic attack, or New York Heart Association (NYHA) functionalclass 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 treatedbasal 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 aclinically important hematological disorder (e.g. aplastic anemia, myeloproliferativeor myelodysplastic syndromes, thrombocytopenia)

• A medical history of active liver disease (other than non-alcoholic hepaticsteatosis), including chronic active hepatitis B or C, primary biliary cirrhosis, orsymptomatic 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 priorstudy start

• On a previous clinical study with ertugliflozin

• Estimated glomerular filtration rate (eGFR) (using the 4-variable Modification of Dietin 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) forfemales

• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2 times upperlimit 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 studystart

• Surgical procedure within 6 weeks prior to study start or major surgery planned duringthe trial

• Positive urine pregnancy test

• Pregnant or breast-feeding, or planning to conceive during the trial, including 14days 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 orengages in binge drinking

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