Pilot Study of the Navigator Continuous Glucose Monitor
Condition: Diabetes Mellitus, Insulin-Dependent
MeSH terms: Diabetes Mellitus; Diabetes Mellitus, Type 1
Study type: Interventional
Phase: Phase 2/Phase 3

Summary: 
      This study is being done to find out how accurate the Navigator continuous glucose monitor is
      in children. It is also being done to see if use of the Navigator can improve blood sugar
      control and help prevent low blood sugar events. This study has three basic parts: Use of the
      Navigator at home for one week without being able to see the blood sugar readings; a Baseline
      visit or a 24-hour admission to a research unit of the hospital to find out how well the
      Navigator measures the blood sugar; and then 3 months use of the Navigator at home as an aid
      to diabetes care.
    

Detailed description: 
      Approximately 60 children will be recruited from five centers in the United States to
      participate in this study. The information gained from this study will be used to plan a
      larger study in which half of the patients will use the Navigator and half will not. Children
      who participate in this study will not be eligible to take part in the larger study.

      The Navigator provides a glucose reading every 60 seconds (or 1440 readings a day). Each
      sensor is designed to provide readings for up to 120 hours. It has alarms for hypoglycemia
      and hyperglycemia and for projected high and low glucose values. The alarm set points can be
      adjusted by the user. The Navigator also has a trend arrow indicating the glucose rate of
      change (>-2 mg/dL/min, -2 to -1 mg/dL/min, -1 to 1 mg/dL/min, 1 to 2 mg/dl/min, and >2
      mg/dl/min). Subjects can enter events, such as when they took insulin, ate, or exercised. The
      sensor requires calibration values to be entered 3 times during the first day of wear at
      1-hour, 3-hours, and 24-hours and does not require additional calibration values. The values
      are entered directly into the Navigator which has a TheraSense Freestyle home glucose meter
      built into the unit. The Navigator has not yet been approved by the FDA. The Navigator
      currently under review by the FDA will limit sensor wear to 3 days.

      Beginning the Study

      When a child enters the study, the following will be done:

        1. Questionnaires will be completed.

             -  Parents and children (if at least 9 years old) will be asked to fill out
                questionnaires on a computer in the clinic. The questions will be about the child's
                diabetes, how the diabetes is being treated, and how the diabetes affects the
                parent and child.

             -  Children who are using insulin pump therapy and are at least 9 years old and
                parents will be interviewed about the child's diabetes management habits at home.
                The interview will be conducted by phone by trained interviewers who are at Nemours
                Children's Clinic in Jacksonville, Florida, one of the study sites.

        2. Blood will be drawn to measure glycosylated hemoglobin (HbA1c).

        3. Parents and children will be instructed on using the Navigator. The first sensor will be
           inserted by the parent or child with guidance from the study nurse. During the first
           week, the parent and child will not be able to see the results from the Navigator.

        4. Children will be asked to do the following before returning for the Baseline Visit or
           the hospital stay about 1 week later:

             -  Check the blood sugar using the Freestyle meter built into the Navigator at least 4
                times a day

             -  Wear the Navigator sensor everyday and change the sensor at the end of day 5

             -  On the day a new sensor is started, do 3 fingerstick blood sugar readings using the
                built-in Freestyle meter to calibrate the Navigator

             -  Enter a meal marker event into the Navigator each time your child has a meal or
                snack

             -  Insert a new sensor 1, 2, 3, or 4 days before your child will stay in the hospital

             -  Bring any used sensors, including the packaging and inserting device to the
                Baseline Visit or hospital stay

      Baseline Visit Children who are using Lantus with MDI therapy will return for a Baseline
      Visit approximately one week (7-12 days) after the enrollment visit.

      Hospital Stay Those children who are using insulin pump therapy will return for a hospital
      stay approximately one week (7-12 days) after the enrollment visit and will use the Navigator
      for about 24 hours. The last sensor that was placed at home will continue to be worn during
      the hospital stay. A new sensor will also be placed so that your child has 2 sensors inserted
      during the hospital stay to see how closely the 2 sensors agree.

      A CGMS sensor will be inserted and calibrated one hour later.

      A small tube called a catheter will be placed in a vein in the child's arm and will stay in
      the vein while the child is in the hospital. From this tube, a very small blood sample will
      be drawn every 30 minutes during the hospital stay. After breakfast, blood samples will be
      taken about every 10 minutes for about an hour. For children who are at least 7 years old,
      blood samples will be taken about every 20 minutes during a period of exercise in the
      afternoon.

      Procedures at Home after the Baseline Visit or Hospital Stay

        1. Use the Navigator.

             -  The Navigator should be worn all of the time for 3 months.

             -  The sensor must be replaced every 5 days.

             -  With each sensor wear 4 blood sugar readings must be done using the built-in
                Freestyle meter to calibrate the Navigator.

             -  Enter a meal marker event into the Navigator each time a meal or snack is eaten.

             -  Children may be asked to insert a new sensor 5 days before some of the study visits
                to allow the study personnel to look at the skin after the sensor has been worn for
                5 days.

        2. Download the Navigator - Once a week, children will need to download the glucose results
           from the Navigator, which will then be emailed to the study coordinating center.

        3. Use Algorithms for Diabetes Management Decisions - The study doctor or nurse will give
           the parents and children instructions (Algorithms) for how to make changes to diabetes
           management from the results of the Navigator. The instructions will be used by the
           parents and children to make decisions as they receive the results from the device.

        4. Phone Interviews - After 3 days and 2, 4, 8, and 10 weeks after the children leave the
           hospital, one of the staff will call to see how they is doing with the Navigator and the
           instructions for diabetes management decisions. We will ask what the child ate in the
           last meal before the call. We also will ask if the child has been sick or under any
           stress. For females who have started menstruating, we will ask about her menstrual
           cycle.

      Study Visits

      Children will return to the diabetes clinics for visits 1, 3, 7, and 13 weeks after the
      hospital stay. At these visits, the following will be done:

        1. Any used sensors, including the packaging and inserting device will be collected.

        2. The skin will be looked at where the Navigator has been worn.

        3. The Navigator and the child's insulin pump will be downloaded and reviewed with the
           parent and child.

        4. The diabetes management instructions will be reviewed with the parent and child to
           determine if the instructions have been helpful or if they need to be changed.

      At the 3, 7, and 13- week visits, parents and children (if at least 9 years old) will be
      asked to complete a questionnaire about how much you liked or disliked the instructions that
      were given for using the results of the Navigator.

      At the 7-week visit, the following will also be done in addition to the child's regular
      clinic visit:

      1. Blood will be drawn to measure the HbA1c.

      At the 13-week visit, the following will also be done in addition to the child's regular
      clinic visit:

        1. Blood will be drawn to measure the HbA1c.

        2. Questionnaires will be completed

             -  Parents and children (if at least 9 years old) will be asked to complete the same
                questionnaires and the phone interview that were done during the first visit.

             -  Parents and children will be asked to complete one more questionnaire about how
                much they like using the Navigator.

        3. If the children are willing to continue using the Navigator, they will be given
           additional sensors to use as often as they would like and they will return for another
           regular clinic visit in about 3 months (26-week visit). At that visit, the skin will be
           looked at where the Navigator was used, the HbA1c will be measured, and the parents and
           children will be asked to complete the same questionnaires that were completed at the
           13-week visit about how much they liked using the Navigator and the instructions that
           were given for using the results of the Navigator.

      Those who decide to continue using the Navigator will be seen again at 26-weeks.

        -  At the 26-week visit, subjects will be given the choice to continue in the study until
           the device is approved by the FDA or until Abbott Diabetes Care can no longer provide
           supplies for the study. Subjects who agree to continue in the study will sign an
           addendum to the informed consent.

        -  Subjects who continue in the study will return to the clinic every 3 months for a
           follow-up visit. The same procedures completed during the 26-week visit will be
           completed at each subsequent visit.
    

Intervention name(s): FreeStyle Navigator Continuous Glucose Monitoring System
Intervention type(s): Device
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Keywords: Diabetes Mellitus, Insulin-Dependent; Type 1 Diabetes; Continuous Glucose Monitoring Devices; Electronic Data Collection