Gastric Modulator (TANTALUS® System) Versus Insulin Treatment in Obese Type 2 Diabetic Patients - a Randomized Control Trial

• changes in body weight before and after interventions at 6 and 12 months [ Time Frame: 6 months and 1 year ] [ Designated as safety issue: No ]
• changes in HbA1c before and after interventions [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• frequency of hypoglycaemia [ Time Frame: 6 month and 1 year ] [ Designated as safety issue: Yes ]
• dichotomous composite end point assessing the proportion of patients meeting all of the following prespecified criteria defined as: 1. HbA1c ≤7.0% or an HbA1c reduction from baseline ≥0.5% 2. no weight gain 3. no severe hypoglycaemia [ Time Frame: 6 and 12 months ] [ Designated as safety issue: Yes ]
• composite quantitative score calculate from the results of glycemic control, weight response and degree of hypoglycemia [ Time Frame: 6 month and 1 year ] [ Designated as safety issue: No ]

• waist circumferences [ Time Frame: 6 month and 1 year ] [ Designated as safety issue: No ]
• insulin secretory responses (as measured by the standard meal test) [ Time Frame: 6 month and 1 year ] [ Designated as safety issue: No ]
• Hormonal profiles (including gut hormones) [ Time Frame: 6 months and 1 year ] [ Designated as safety issue: No ]
• a. eating behavior, satiety and quality of life as measured by the Food Frequency Questionnaire, Visual Analogue Rating Scale To Assess Satiety, EDE, SF-36 and GIQOL questionnaires [ Time Frame: 6 month and 1 year ] [ Designated as safety issue: No ]
• resting energy expenditure as monitored by indirect calorimetry (MedGem). [ Time Frame: 6 month and 1 year ] [ Designated as safety issue: No ]
• radiological assessment (ultrasound scan and densitometry to measure mesenteric and total body fat respectively) [ Time Frame: 6 months and 1 year ] [ Designated as safety issue: No ]
• differences in insulin requirement [ Time Frame: 1 year ] [ Designated as safety issue: No ]

This study aims to analyze the pre- and post-operative clinical, hormonal and biochemical changes in moderately obese type 2 diabetic patients who are sub-optimally controlled on at least 2 anti-diabetic agents. Study participants will either receive implantation of the gastric contraction modulator or conventional treatment with insulin therapy.

• Device: Tantalus
  The TANTALUS System is implanted using minimally invasive procedure (laparoscopy). It uses leads with stitch electrodes to deliver electrical signals to the gastric wall for the treatment of obese subjects with T2DM.
• Drug: Insulin
  Insulin treatment will be prescribed, in accordance with the common medical practice at the institute. Dosages will be recorded on a daily basis.

• Experimental: Tantalus
  The TANTALUS System is implanted using minimally invasive procedure (laparoscopy). It uses leads with stitch electrodes to deliver electrical signals to the gastric wall for the treatment of obese subjects with T2DM. The device is intended to improve glycemic control and induce weight loss.
  Intervention: Device: Tantalus
• Active Comparator: Control
  Insulin treatment will be prescribed, in accordance with the common medical practice at the institute. Dosages will be recorded on a daily basis.
  Intervention: Drug: Insulin

Inclusion Criteria:

• Able to provide written informed consent
• Adult patients aged between 18 and 60 years (inclusive)
• Male or female of Chinese ethnicity
• Type 2 diabetes mellitus with disease duration of greater than 2 and less than 10 years
• severe obesity, includes BMI 25 to 27.5 kg/m and central obesity defined by waist circumference greater than 90 cm in women and greater than 95 in men, or BMI greater than 27.5 to less than 35 kg/m
• HbA1c greater than or equals to 7.5% but less than 10% despite treated with maximum dose or maximally tolerated dose of 2 anti-diabetic drugs (OAD) with good drug compliance

Exclusion Criteria:

• On anti-obesity drugs
• On insulin treatment at the time of the recruitment
• On glitazone or incretins (dipeptidyl peptidase-4 inhibitor or glucagons-like peptide-1) treatment
• On any implantable device including cardiac pacing
• Anticipated to have MRI examinations
• Fasting C-peptide level less than 0.5g/L
• Renal impairment (defined as serum creatinine greater than 150mol/L and/or estimated glomerular filtration rate less than 60 mL/min/1.73m)
• Significant liver impairment (ALT more than 3 times upper limit of normal range)
• Active malignant disease. Patients with malignant disease who have been disease-free for at least 5 years are eligible
• Active infection
• Active and uncontrolled thyroid diseases
• Childbearing age female patients without reliable contraceptive methods
• Life expectancy less than 12 months
• Administration of another investigational drugs or procedures within 4 weeks before screening
• Any medical illness or condition as judged by the investigators as ineligible to participate the study
• Special population, e.g. prisoner, mentally disabled, investigators' student or employees