The purpose of this study is to evaluate the safety, tolerability, pharmacodynamic effects and pharmacokinetic characteristics of JNJ-28431754 after multiple dosing in patients with Type 2 Diabetes Mellitus who are on a stable dose of insulin.

This is a randomized (study drug assigned by chance), double-blind (neither the patient or the study doctor will know the name of the assigned treatment), parallel-group (each group of patients will be treated at the same time) to determine the safety, tolerability, pharmacokinetics (PK) (how drugs are absorbed in the body, how they are distributed within the body and how they are removed from the body over time) and the pharmacodynamics (PD) (the action or effects a drug has on the body) of oral (taken by mouth) doses of JNJ 28431754 taken once or twice daily compared to placebo (treatment identical in appearance to JNJ-2843174 but contains no active drug) in patients with Type 2 Diabetes Mellitus (T2DM) who are receiving therapy with a fixed-dose regimen of insulin. Two groups of 14 patients will be studied; one group will receive JNJ-2843174 (100 mg) or placebo once daily for 4 weeks and the other group will receive JNJ-2843174 (300 mg) or placebo twice daily for 4 weeks. In the 3 days immediately prior to the beginning of the 4-week treatment period, all patients will take a single oral dose of placebo once daily and have blood and urine samples collected for laboratory testing. During the study, all patients will be allowed to continue on their normal medication regimen of insulin and other allowed anti-diabetic medications. On selected days during the study, patients will be required to stay overnight at the study center to have study drug administered and/or to have blood and urine samples collected for laboratory testing. During the study, if patients experience worsened glycemia (blood sugar), rescue therapy with additional insulin of the same type but at a higher dose may be initiated by the Investigator if medically appropriate. During the study, patients will be monitored for safety by review of adverse events and results from laboratory tests, 12-lead electrocardiograms (ECGs), vital signs measurements, body weight, physical examinations, and self-monitored blood glucose (SMGB) measurements. Unless otherwise specified, study drug will be taken orally (by mouth) after an overnight fast for at least 8 hours followed by a meal within 10 minutes; for twice daily dosing, the evening dose will be taken just prior to the evening meal (dinner). All patients will take one placebo capsule once daily for 3 days immediately prior to randomization. After randomization, patients will take JNJ-28431754 (100 mg) or placebo once daily or JNJ-28431754 (300 mg) or placebo twice daily for 4 weeks.

Inclusion Criteria:

• Have been diagnosed with T2DM for at least 6 months prior to study screening
• Be on stable insulin regimens at the time of screening
• Have a stable weight (ie, no change more than 5% in the 3 months prior to screening)
• Have a glycosylated hemoglobin (A1C) of >=7% and <=10.5% at study screening

Exclusion Criteria:

• Have history of Type 1 diabetes mellitus, secondary forms of diabetes, diabetic ketoacidosis, pancreas or beta cell transplantation
• Have a known history of more than 2 severe hypoglycemic episodes as defined by the protocol within the past year
• Have history of, or currently active, significant illness as determined by the Investigator