• Change from baseline in percentage of total body weight lost and percentage of subjects who achieve a weight decrease of ≥ 5% [ Time Frame: 56 weeks ] [ Designated as safety issue: No ]
  

• Proportion of subjects who lose at least 10% of baseline body weight and who achieve a HbA1c value < 7%; Change in HbA1c; Effects on selected obesity-associated risk factors [ Time Frame: Baseline to week 56 ] [ Designated as safety issue: No ]
  

Optimal care of patients with diabetes mellitus includes vigorous and persistent efforts to achieve physiologic control of blood glucose as well as other often associated conditions including hypertension, dyslipidemia and excess weight. Pharmacologic interventions for the treatment of obesity in type 2 diabetes have shown significant reductions in HbA1c. In previous studies in uncomplicated obesity, the combination of bupropion SR and naltrexone was generally well tolerated and,more effective than placebo alone and naltrexone alone, and generally more effective than bupropion monotherapy in producing weight loss. The purpose of the current study is to investigate the safety and efficacy of the naltrexone SR and bupropion SR combination in obese subjects with type 2 diabetes mellitus.

Inclusion Criteria:

• Have body mass index(BMI) between 27 and 45 kg/m2
• Diagnosed with Diabetes Mellitus type 2 and on no injectable hypoglycemic medication or inhaled insulin for more than 3 months
• On oral single or combination hypoglycemic medications or no medications for the treatment of type 2 diabetes mellitus. Oral hypoglycemic medication must be stable for at least 3 months prior to randomization
• Normotensive (<140/90 mm Hg); some anti-hypertensive medications are allowed
• HbA1c between 7and 10%, fasting blood glucose <270 mg/ml, fasting triglycerides <400 mg/dL.
• Women of child bearing potential must have a negative serum pregnancy test, must be non-lactating and agree to use effective contraception throughout the study period and 30 days after stopping study drug.

Exclusion Criteria:

• Type I Diabetes Mellitus.
• Subjects with "brittle-diabetes" or any hospitalization or emergency room visit due to poor diabetic control within the past 6 months, previous history of diabetes-related dehydration leading to hospitalization, history or evidence of ketoacidosis.
• Diabetes Mellitus secondary to pancreatitis or pancreatectomy.
• Serious medical conditions
• Loss or gain of more than 5.0 kilograms (11 pounds) within previous 3 months
• Severe microvascular or macrovascular complications of diabetes
• Serious psychiatric illness
• In need of medications for the treatment of a psychiatric disorder (with the exception of short-term insomnia) within the previous 6 months
• On prohibited concomitant medications
• History of surgical or device (e.g. gastric banding) intervention for obesity
• History of seizures or predisposition to seizures