A Clinical Study of the Performance of a Glucose Blinding Protein-Based Continuous Glucose Monitor (GBP CGM)
Condition: Type 1 Diabetes Mellitus
MeSH terms: Diabetes Mellitus, Type 1
Study type: Interventional
Phase: Phase 2

Summary: 
      The purpose of this study is to assess the accuracy of the Becton Dickenson (BD) Technologies
      Glucose Binding Protein-Based Continuous Glucose Monitor (GBP CGM) in patients with Type 1
      diabetes during low (goal glucose 55 mg/dL), normal (80-140 mg/dL) and high (>180mg/dL)
      glucose levels over a 24 hour period. This will be achieved by monitoring blood sugar levels
      when a regular dinner meal is given, when a liquid breakfast meal (BOOST Original containing
      41 grams Carbohydrates (CHO), 4 grams fat, 10 grams protein) is given, when subcutaneous
      insulin is dosed to induce hypoglycemia to a goal of 55 mg/dL, and when a regular lunch meal
      is given. A Continuous Glucose Monitor (CGM) is an electronic device that measures and
      displays blood sugar (glucose) levels in the body throughout the day and night. The method
      being used to detect blood sugar in the investigational Glucose Binding Protein-Based
      Continuous Glucose Monitor (GBP CGM) is different than the method that is currently in use by
      commercially available models.

      Some sensors cannot tell the difference between glucose (sugar) and other substances such as
      Tylenol, aspirin or citric acid etc. Because they cannot tell the difference, they may give
      false readings. The GBP CGM is made to only recognize glucose in the body rather than other
      substances (e.g., Tylenol, aspirin, citric acid, etc.). As a result, the investigators expect
      the new GBP CGM to be more accurate at detecting low blood sugar levels than the current
      devices.
    

Detailed description: 
      Development of accurate continuous glucose monitoring devices is critically important for the
      maintenance of strict glycemic control without increasing the risk for hypoglycemia and for
      the successful implementation of an artificial pancreas. Glucose binding protein-based (GBP)
      continuous glucose monitors offer several potential advantages over commercially available
      glucose oxidase based sensors. Unlike glucose oxidase based sensors, GBP sensors do not
      require establishment of an equilibrium reduction/oxidation reaction and are not as
      susceptible to interference from other compounds because they are engineered to recognize
      only glucose. As a result, GBP-based glucose sensors are exceptionally accurate at low blood
      glucose levels and have a faster warm-up time than glucose oxidase based systems. The
      principal idea of this proposal is to evaluate the accuracy and performance of a second
      generation glucose binding protein-based continuous glucose monitor (GBP CGM) developed by BD
      Technologies in subjects with type 1 diabetes, with emphasis on warm-up period after
      insertion, accuracy in hypoglycemic and hyperglycemic ranges, and lag time over a 24 hour
      period of sensor use. In order to accomplish this, the investigators will conduct a clinical
      trial consisting of 25.5-hour studies involving 15 subjects, each wearing one active and one
      mock (no GBP) device simultaneously during meals and induced hypoglycemia to observe a wide
      range of glucose values. The investigators envision that the glucose binding protein-based
      continuous glucose monitor will demonstrate minimal warm-up time after insertion, overall
      accuracy comparable to commercial glucose oxidase sensors with excellent performance in the
      hypoglycemic range and a nominal lag time to sensing a change in blood glucose.
    

Intervention name(s): GBP CGM
Intervention type(s): Device
Intervention description(s): Visit 1: Screening visit to determine if subject qualifies for the study. Visit 2: Inpatient admission requiring a 25.5-hour hospital stay. Each subject will wear one active & one mock device simultaneously during hyperglycemic & hypoglycemic challenge conditions to observe a wide range of glucose values. Visit 3 & 4: Subjects will return to the research center approximately 24 & 48 hours after sensor removal, respectively, for evaluation of the postimplantation sensor site. Visit 5: Subjects will return to the research center approximately 28 days post inpatient admission. Blood samples for future testing of GBP and polyethylene Glycol neutralizing antibodies will be taken at Visit 1 & 5.
Other intervention name(s): Glucose binding protein-based continuous glucose monitor
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Supportive Care
Keywords: Continuous Glucose Monitor