Safety and Effectiveness Study of a Closed Loop System Maintaining Patients' Glucose Levels During an Overnight Period

This study is currently recruiting participants. (see Contacts and Locations)
Verified November 2013 by Medtronic Diabetes
Sponsor:
Information provided by (Responsible Party):
Medtronic Diabetes
ClinicalTrials.gov Identifier:
NCT01712594
First received: October 19, 2012
Last updated: November 18, 2013
Last verified: November 2013
  Purpose

Currently, patients diagnosed with type 1 diabetes rely on either finger stick or sensor glucose readings when making their insulin dosage decisions. Designing a computerized system that mimics the way insulin is produced naturally in a person who does not have type 1 diabetes holds many challenges; all of which cannot be addressed in just one study. The purpose of the Medtronic Overnight Closed Loop study is to assess the performance of a system designed to automatically infuse the correct insulin dose during the hours that the patient is sleeping.

The system consists of an insulin pump that provides insulin to the patient through an infusion set. A sensor inserted just under the patient's skin measures glucose levels and a transmitter sends this information to the pump. To enable the sensor to register the glucose information correctly, it must be set (calibrated) by a finger stick blood glucose 3-4 times a day. In the commercially released system, the physician would recommend the continuous background (basal) insulin rates and the patient would be required to make decisions regarding extra insulin (bolus) for meals or as a response to high glucose levels.

In the Closed Loop System, a mobile control system is added to these devices. This consists of an Android phone, a closed loop algorithm and a translator. This system is designed to translate the sensor information and direct the pump to provide the required dosage of insulin automatically without requiring input from the patient.

Reliable calibration has proved challenging, and so it is important that the system function safely, even when calibration is inaccurate. In this study, a calibration error will be introduced under very controlled circumstances. This testing will identify if the system can maintain acceptable overnight glucose levels, regardless of whether or not calibration is ideal.


Condition Intervention Phase
Type 1 Diabetes
Device: Closed Loop Procedure (Medtronic)
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Feasibility and Safety of a Closed Loop Insulin Delivery System (Aka AAGC) With an Artificially Induced Calibration Error During the Overnight Period

Resource links provided by NLM:


Further study details as provided by Medtronic Diabetes:

Primary Outcome Measures:
  • Amount of time spent in the target range defined as 3.8-8.8 mmol/l (70 to 160 mg/dL) YSI glucose during in-clinic overnight visits [ Time Frame: Two in-patient nights ] [ Designated as safety issue: Yes ]
    Subjects will arrive at the research facility between 17:00 and 18:00. Plasma glucose will be measured and they will have their evening meal of no more than 80 g of carbohydrate. They will bolus for this meal using their usual Bolus Wizard (Medtronic) settings. After the meal, an IV catheter will be inserted for the collection of venous blood samples. The Mobile Control System will be connected and closed-loop control will be started approximately 4 hours after dinner. The subject will remain under closed-loop control overnight (approximately 11 p.m.-6 a.m.). During one of the Closed Loop nights the system will be challenged by a calibration error of 30%. At approximately 7 am (before breakfast), the Mobile Control System will be turned off and the patient will be provided with a breakfast (approximately 40-70 gm of carbohydrate) and will take a bolus according to the Bolus Wizard. The patient will return to their usual pump treatment with the MiniMed Paradigm Veo System.


Secondary Outcome Measures:
  • Glucose Area under the curve (AUC) below 3.8 mmol/l (70 mg/dL ) YSI glucose obtained during in-clinic overnight visits [ Time Frame: Two overnight closed loop sessions ] [ Designated as safety issue: Yes ]
    Blood glucose samples will be obtained from the line approximately every 30 minutes, or every 5-15 minutes at treating physician's discretion, if either the sensor or a previous glucose reading is < 81mg/dL or > 360mg/dL (< 3.5 mmol/l or > 20 mmol/l). Plasma samples will be analyzed using a YSI 2300 Glucose and Lactate Analyzer between 18:00 and 6:00.

  • Glucose AUC above 8.8mmol/l (160 mg/dL) YSI glucose obtained during in-clinic overnight visits [ Time Frame: Two overnight closed loop sessions ] [ Designated as safety issue: Yes ]
    Blood glucose samples will be obtained from the line approximately every 30 minutes, or every 5-15 minutes at treating physician's discretion, if either the sensor or a previous glucose reading is < 81mg/dL or > 360mg/dL (< 3.5 mmol/l or > 20 mmol/l). Plasma samples will be analyzed using a YSI 2300 Glucose and Lactate Analyzer (YSI, Inc., OH, USA) between 18:00 and 6:00.


Other Outcome Measures:
  • All descriptive endpoints stratified by the accuracy of the sensor based on mean absolute relative difference (MARD) overnight [ Time Frame: Two overnight closed loop sessions ] [ Designated as safety issue: Yes ]
    A meter blood glucose (BG) value is entered into the Android and a sensor and calibration error check are performed. If the routine determines that the sensor and BG are valid values, the Closed Loop will start.


Estimated Enrollment: 18
Study Start Date: May 2013
Estimated Study Completion Date: April 2015
Estimated Primary Completion Date: August 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Closed Loop Procedure AB
Closed loop procedure with normal calibration first followed by closed loop procedure B with calibration error induced.
Device: Closed Loop Procedure (Medtronic)
The procedure A is the device running under normal conditions, procedure B will incorporate an induced calibration error.
Other Name: AAGC
Active Comparator: Closed loop Procedure BA
Closed loop procedure with an induced calibration error first followed by closed loop procedure with normal calibration.
Device: Closed Loop Procedure (Medtronic)
The procedure A is the device running under normal conditions, procedure B will incorporate an induced calibration error.
Other Name: AAGC

  Eligibility

Ages Eligible for Study:   18 Years to 70 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • A clinical diagnosis of Type 1 diabetes as determined by the Investigator for a minimum of 36 months prior to enrollment
  • Weight is between 50 and 120 kg
  • Subject has used a Medtronic insulin pump for at least the previous 6 months
  • Subject has an glycated hemoglobin (A1C) value ≤ 9.0% demonstrated at the time of enrollment
  • Subject uses a rapid-acting analogue insulin in his/her pump

Exclusion Criteria:

  • Female subject who has a positive serum pregnancy screening test, or who plans to become pregnant during the course of the study
  • Subject has a history of hypoglycemic seizure or hypoglycemic coma within the past 12 months
  • Subject has an exclusionary cardiac disorder
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01712594

Contacts
Contact: Yiming Deng +18185765472 yiming.deng@medtronic.com

Locations
United Kingdom
King's College London Recruiting
London, United Kingdom, SE5 9PJ
Contact: Pratik Choudhary, MD    44 203 299 1737    pratik.choudhary@kcl.ac.uk   
Principal Investigator: Pratik Choudhary, MBBS MRCP MD         
Sponsors and Collaborators
Medtronic Diabetes
  More Information

No publications provided

Responsible Party: Medtronic Diabetes
ClinicalTrials.gov Identifier: NCT01712594     History of Changes
Other Study ID Numbers: CEP223
Study First Received: October 19, 2012
Last Updated: November 18, 2013
Health Authority: United Kingdom: Medicines and Healthcare Products Regulatory Agency

Keywords provided by Medtronic Diabetes:
United Kingdom Overnight closed loop

Additional relevant MeSH terms:
Diabetes Mellitus, Type 1
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Autoimmune Diseases
Immune System Diseases

ClinicalTrials.gov processed this record on July 22, 2014