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

NCT01712594 | Completed FDA Device

• 1 other identifier: CEP223
• Study Type: interventional
• Target: 9
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Type 1 Diabetes

Keywords

United Kingdom Overnight closed loop

Outcome Measures

Primary Outcomes (1)

• 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

  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.

  Two in-patient nights

Secondary Outcomes (2)

• Glucose Area under the curve (AUC) below 3.8 mmol/l (70 mg/dL ) YSI glucose obtained during in-clinic overnight visits

  Two overnight closed loop sessions

• Glucose AUC above 8.8mmol/l (160 mg/dL) YSI glucose obtained during in-clinic overnight visits

  Two overnight closed loop sessions

Other Outcomes (1)

• All descriptive endpoints stratified by the accuracy of the sensor based on mean absolute relative difference (MARD) overnight

  Two overnight closed loop sessions

Study Arms (2)

Closed Loop Procedure AB

ACTIVE COMPARATOR

Closed loop procedure with normal calibration first followed by closed loop procedure B with calibration error induced.

Device: Closed Loop Procedure (Medtronic)

Closed loop Procedure BA

ACTIVE COMPARATOR

Closed loop procedure with an induced calibration error first followed by closed loop procedure with normal calibration.

Device: Closed Loop Procedure (Medtronic)

Interventions

Closed Loop Procedure (Medtronic) DEVICE

The procedure A is the device running under normal conditions, procedure B will incorporate an induced calibration error.

Also known as: AAGC

Closed Loop Procedure AB; Closed loop Procedure BA

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Medtronic Diabetes: lead

Study Sites (1)

King's College London

London, SE5 9PJ, United Kingdom

Location

MeSH Terms

Conditions

Diabetes Mellitus, Type 1

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 19, 2012
• First Posted: October 23, 2012
• Study Start: May 1, 2013
• Primary Completion: December 1, 2013
• Study Completion: December 1, 2014
• Last Updated: May 12, 2017

Record last verified: 2017-05

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)