This is a 3-month extension study (DCLP3 Extension) following a primary trial (DCLP3 or NCT03563313) to assess efficacy and safety of a closed loop system (t:slim X2 with Control-IQ Technology) in a large randomized controlled trial. Upon completion of the NIH 3-month extension study, subjects will be invited to participate in a continued use phase with Control-IQ Technology, funded by Tandem Diabetes Care, until the equipment has received FDA approval for commercial use.
Participants in the 6 month primary trial (DCLP3) will be invited to continue in this 3-month extension study (DCLP3 Extension) following completion of the primary trial. The closed-loop control (CLC) Intervention Group participants from the primary trial will be randomly assigned to continue CLC or to switch to Predictive Low-Glucose Suspend (PLGS) therapy with t:slim X2 with Basal-IQ and Dexcom G6 for 3 months. The Sensor-Augmented Pump (SAP) Control Group participants from the primary trial will be assigned to CLC using t:slim X2 with Control-IQ Technology and Dexcom G6 (CGM) for 3 months. Upon completion of the extension study, subjects will be invited to participate in continued use of the Control-IQ Technology until the equipment has received FDA approval for commercial use. This extension phase has two separate objectives: Objective 1: Among participants who used CLC in the primary trial: the primary efficacy outcome for the randomized controlled trial (RCT) is time in target range 70-180 mg/dL measured by CGM in CLC group vs. PLGS group over 3 months. Safety outcomes also will be assessed Objective 2: Among participants who used SAP in the primary trial: the primary outcome is to obtain additional safety data. Efficacy also will be assessed as a pre-post within participant analysis Note: Primary Trial (DCLP3) is NCT03563313
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
164
Participants will use the Tandem t:slim X2 insulin pump with Control-IQ Technology \& Dexcom G6 CGM for 3 months.
Participants will use a Tandem t:slim X2 insulin pump with Basal-IQ and a study CGM (Dexcom G6) for 3 months.
Sansum Diabetes Research Institute
Santa Barbara, California, United States
Stanford University
Stanford, California, United States
Barbara Davis Center, University of Colorado
Aurora, Colorado, United States
Harvard University (Joslin Diabetes Center)
Boston, Massachusetts, United States
Time in Target Range
The primary exploratory outcome is time in target range 70-180 mg/dL measured by CGM comparing the randomized groups CLC vs PLGS. Results from SAP to CLC group is also included here without the primary intention of comparing to CLC vs PLGS groups.
Time frame: 13 weeks
CGM Time Above 180
CGM-measured % above 180 mg/dL
Time frame: 13 weeks
CGM Mean Glucose
CGM-measured mean glucose
Time frame: 13 weeks
CGM Time Below 70
CGM-measured % below 70 mg/dL
Time frame: 13 weeks
CGM Time Below 54
CGM-measured % below 54 mg/dL
Time frame: 13 weeks
CGM Time in Range 70-140 mg/dL
CGM-measured % in range 70-140 mg/dL
Time frame: 13 weeks
Coefficient of Variation
CGM measured glucose variability measured with the coefficient of variation (CV)
Time frame: 13 weeks
Standard Deviation
CGM measured glucose variability measured with the standard deviation (SD)
Time frame: 13 weeks
CGM Time Below 60
CGM-measured % below 60 mg/dL
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Mayo Clinic
Rochester, Minnesota, United States
Icahn School of Medicine at Mount Sinai
New York, New York, United States
University of Virginia Center for Diabetes Technology
Charlottesville, Virginia, United States
Time frame: 13 weeks
LBGI
Low blood glucose index by CGM with higher index indicating higher risk of hypoglycemia. Values \<1 suggest minimal risk. Index of risk of low blood glucose excursion based on a standard formula for non-linear transformation of the blood glucose scale (Kovatchev BP, Cox DJ, Gonder-Frederick LA, Young-Hyman D, Schlundt D, Clarke WL: Assessment of risk for severe hypoglycemia among adults with IDDM: validation of the low blood glucose index. Diabetes Care 21:1870-1875, 1998)
Time frame: 13 weeks
CGM Hypoglycemia Events
CGM-measured events of at least 15 consecutive minutes \<70 mg/dL
Time frame: 13 weeks
CGM Time >250
CGM-measured % \>250 mg/dL
Time frame: 13 weeks
CGM Time >300
CGM-measured % \>300 mg/dL
Time frame: 13 weeks
HBGI
High blood glucose index by CGM with higher values indicating higher risk of hyperglycemia. Index of risk of high blood glucose excursion based on a standard formula for non-linear transformation of the blood glucose scale (Kovatchev BP, Cox DJ, Kumar A, Gonder-Frederick L, Clarke WL. Algorithmic evaluation of metabolic control and risk of severe hypoglycemia in type 1 and type 2 diabetes using self-monitoring blood glucose data. Diabetes Technol Ther 2003;5:817-828pmid:14633347)
Time frame: 13 weeks
HbA1c at 13 Weeks
HbA1c at 13 weeks.
Time frame: 13 weeks
HbA1c <7.0% at 13 Weeks
HbA1c \<7.0% at 13 weeks.
Time frame: 13 weeks
HbA1c <7.5% at 13 Weeks
HbA1c \<7.5% at 13 weeks.
Time frame: 13 weeks
HbA1c Change From Baseline to 13 Weeks >0.5%
HbA1c change from baseline to 13 weeks \>0.5%.
Time frame: 13 weeks
HbA1c Change From Baseline to 13 Weeks >1.0%
HbA1c change from baseline to 13 weeks \>1.0%.
Time frame: 13 weeks
HbA1c Relative Change From Baseline to 13 Weeks >10%
HbA1c relative change from baseline to 13 weeks \>10%.
Time frame: 13 weeks
HbA1c Change From Baseline to 13 Weeks >1.0% or HbA1C <7.0% at 13 Weeks
HbA1c change from baseline to 13 weeks \>1.0% or HbA1c \<7.0% at 13 weeks.
Time frame: 13 weeks
HFS-II Adult
Fear of Hypoglycemia Survey (HFS-II) total score and 3 sub scales (5 point scale with never to almost always) For adults, teens and parents items on this survey are rated on a 5 point Likert scale from never (0) to almost always (4). The survey is scored by summing item responses. Fear of Hypoglycemia Survey (HFS-II) for adults has a total score that is summed from the two subscale scores (33 items) and ranges from 0 to 132 with higher scores indicating greater degrees of fear of hypoglycemia.
Time frame: 13 weeks
HFS-II Teen
Fear of Hypoglycemia Survey (HFS-II) total score and 3 sub scales (5 point scale with never to almost always) For adults, teens and parents items on this survey are rated on a 5 point Likert scale from never (0) to almost always (4). The survey is scored by summing item responses.The teen survey has a total of 25 items and the range of Total scores is 0 to 100.
Time frame: 13 weeks
HFS-II Parents
Fear of Hypoglycemia Survey (HFS-II) total score and 3 sub scales (5 point scale with never to almost always) For adults, teens and parents items on this survey are rated on a 5 point Likert scale from never (0) to almost always (4). The parent version of the survey has a total of 26 items with Total scores that range from 0 to 108.
Time frame: 13 weeks
Hyperglycemia Avoidance Scale
Hyperglycemia Avoidance Scale total score is the sum of 21 items rated on a 4 point Likert scale from 0 (never) to 4 (almost always) and ranges from 0 to 84 with a higher score indicating greater degrees of avoiding hyperglycemia.
Time frame: 13 weeks
Diabetes Distress Scale
Diabetes Distress Scale for adults has 28 items rated on a 6 point Likert scale that ranges from 1 (not a problem) to 6 (a very serious problem). The total score is the mean of the sum of responses and ranges from 1 to 6 where a higher score indicates greater degrees of diabetes distress.
Time frame: 13 weeks
Hypoglycemia Confidence Scale
Hypoglycemia Confidence Scale has 9 items which are self-rated on a 4-point Likert Scale ranging from 1 (not confident at all) to 4 (very confident) with higher scores indicating higher confidence in dealing with hypoglycemia. A single score is computed by calculating the mean of the sum of all items and ranges from 1 to 4.
Time frame: 13 weeks
Clarke Hypoglycemia Awareness Scores
Clarke Hypoglycemia Awareness Scores (0-7 score with higher scores associated with impaired awareness)
Time frame: 13 weeks
INSPIRE Survey Scores- Adults
The INSPIRE questionnaire assesses user expectations and experiences with Insulin Delivery Systems: Perceptions, Ideas, Reflections, Expectations (INSPIRE). Survey total scores are computed by calculating the mean of the sum of all item ratings then multiplying the mean by 25 to scale the score to a range from 0 to 100. Higher scores indicate a more positive perception of insulin delivery systems. Items are rated on a 5 point Likert scale ranging from 0 (strongly disagree) to 4 (strongly agree). The Adult survey has 22 items.
Time frame: 13 weeks
INSPIRE Survey Scores- Teens
The INSPIRE questionnaire assesses user expectations and experiences with Insulin Delivery Systems: Perceptions, Ideas, Reflections, Expectations (INSPIRE). Survey total scores are computed by calculating the mean of the sum of all item ratings then multiplying the mean by 25 to scale the score to a range from 0 to 100. Higher scores indicate a more positive perception of insulin delivery systems. Items are rated on a 5 point Likert scale ranging from 0 (strongly disagree) to 4 (strongly agree). The Teens/Adolescents survey has 17 items.
Time frame: 13 weeks
INSPIRE Survey Scores- Parents
The INSPIRE questionnaire assesses user expectations and experiences with Insulin Delivery Systems: Perceptions, Ideas, Reflections, Expectations (INSPIRE). Survey total scores are computed by calculating the mean of the sum of all item ratings then multiplying the mean by 25 to scale the score to a range from 0 to 100. Higher scores indicate a more positive perception of insulin delivery systems. Items are rated on a 5 point Likert scale ranging from 0 (strongly disagree) to 4 (strongly agree). The Parent survey has 21 items.
Time frame: 13 weeks
System Usability Scores (SUS)
System Usability Scores (SUS)-composite score from 0 to 100 with higher scores indicating better perceived usability
Time frame: 13 weeks
Technology Acceptance Questionnaire
Technology Acceptance Survey measures the user's perceptions regarding the burdens and the barriers associated with a technology with a higher score indicates increased technology acceptance. There total score uses 37 items with items are rated on a 5 point scale ranging from 1 (strongly disagree) to 5 (strongly agree) for total score range of 37-185.
Time frame: 13 weeks
Total Daily Insulin
Total Daily Insulin (units/kg)
Time frame: 13 weeks
Basal:Bolus Insulin Ratio
Basal:Bolus Insulin Ratio.
Time frame: 13 weeks
Weight
Weight (kg)
Time frame: 13 weeks
BMI
Body Mass Index (BMI) kg/m2
Time frame: 13 weeks