Type 1 Diabetes MellitusNCT03591354
The International Diabetes Closed Loop (iDCL) Trial: Clinical Acceptance of the Artificial Pancreas (DCLP3 Extension)
A study testing t:slim X2 with Basal-IQ & Dexcom G6 CGM in people with Type 1 Diabetes Mellitus, run by University of Virginia at 7 sites in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 14 years and older
- Conditions the study is for
- Type 1 Diabetes Mellitus
- What is being tested?
- t:slim X2 with Basal-IQ & Dexcom G6 CGM
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 164 participants
- Where
- 7 sitesUnited States
- Study dates
- 17 Jan 2019to 9 Mar 2020
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 14 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Successful completion of the original 6-month RCT within the prior 14 days
- For females, not currently known to be pregnant. If female and sexually active, must agree to use a form of contraception to prevent pregnancy while a participant in the study. A negative urine pregnancy test will be required for all females of child-bearing potential. Participants who become pregnant will be discontinued from the study. Also, participants who during the study develop and express the intention to become pregnant within the timespan of the study will be discontinued.
- For participants <18 years old, living with one or more parent/legal guardian knowledgeable about emergency procedures for severe hypoglycemia and able to contact the participant in case of an emergency.
- Willingness to not use a personal CGM for the duration of the study
- Investigator has confidence that the participant can successfully operate all study devices and is capable of adhering to the protocol
- Willingness to use only lispro (Humalog) or aspart (Novolog), and to use no other insulin during the study.
- Willingness not to start any new non-insulin glucose-lowering agent during the course of the trial
Who cannot join
- Concurrent use of any non-insulin glucose-lowering agent other than metformin (including GLP-1 agonists, Symlin, DPP-4 inhibitors, SGLT-2 inhibitors, sulfonylureas).
- Hemophilia or any other bleeding disorder
- A condition, which in the opinion of the investigator or designee, would put the participant or study at risk
- Participation in another pharmaceutical or device trial at the time of enrollment or during the study
- Employed by, or having immediate family members employed by Tandem Diabetes Care, Inc., Dexcom, Inc., or TypeZero Technologies, LLC, or having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial
Trial locations and contacts
7 sites in 1 country.
7 sites in 1 country
United States7 sites
Barbara Davis Center, University of Colorado
Aurora, Colorado, 80045
Harvard University (Joslin Diabetes Center)
Boston, Massachusetts, 02215
University of Virginia Center for Diabetes Technology
Charlottesville, Virginia, 22903
Icahn School of Medicine at Mount Sinai
New York, New York, 10029
Mayo Clinic
Rochester, Minnesota, 55905
Sansum Diabetes Research Institute
Santa Barbara, California, 93105
Stanford University
Stanford, California, 94304
About this study
Official title: An Extension Study of t:Slim X2 With Control-IQ Technology
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.
Read the detailed description
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
- Conditions
- Type 1 Diabetes Mellitus
- Being tested
- t:slim X2 with Control-IQ Technology & Dexcom G6 CGM, t:slim X2 with Basal-IQ & Dexcom G6 CGM
- Keywords
- Artificial Pancreas (AP), Type 1 Diabetes Mellitus, Insulin Pump, Continuous Glucose Monitor (CGM), Closed Loop Control (CLC), Sensor-Augmented Pump (SAP)
- Medical subject headings
- Diabetes Mellitus, Type 1
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
t:slim X2 with Control-IQ Technology & Dexcom G6 CGMDevice
Participants will use the Tandem t:slim X2 insulin pump with Control-IQ Technology \& Dexcom G6 CGM for 3 months.
t:slim X2 with Basal-IQ & Dexcom G6 CGMDevice
Participants will use a Tandem t:slim X2 insulin pump with Basal-IQ and a study CGM (Dexcom G6) for 3 months.
| Study group | Role | What they receive |
|---|---|---|
| Closed Loop Control (CLC) | Experimental | Participants randomized to the closed loop control (CLC) arm will use the t:slim X2 with Control-IQ Technology \& Dexcom G6 Continuous Glucose Monitor (CGM) for 3 months.
Objective 1: This arm is participants who had 6 months of CLC in the primary trial (DCLP3 Pivotal Trial)
Objective 2: This arm is participants who had 6 months of sensor-augmented pump (SAP) in the primary trial (DCLP3 Pivotal Trial)
Objective 3: This arm is participants who had 3 months of CLC in the extension trial (DCLP3 Extension) will continue use of the Control-IQ Technology \& Dexcom G6 CGM until the product is commercially available. Receives: Device: t:slim X2 with Control-IQ Technology & Dexcom G6 CGM |
| Predictive-Low Glucose Suspend (PLGS) | Active comparator | Participants randomized to Predictive-Low Glucose Suspend (PLGS) will use the t:slim X2 with Basal-IQ \& Dexcom G6 CGM for 3 months.
Objective 1: This arm is participants who had 6 months of PLGS in the primary trial (DCLP3 Pivotal Trial)
Objective 2: This arm is not applicable to objective 2
Objective 3: This arm is participants who had 3 months of PLGS in the extension trial (DCLP3 Extension) will continue use of the Control-IQ Technology \& Dexcom G6 CGM until the product is commercially available. Receives: Device: t:slim X2 with Basal-IQ & Dexcom G6 CGM |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 13 weeks
Secondary outcomes (36)
CGM Time Above 180
CGM-measured % above 180 mg/dL
Measured: 13 weeks
CGM Mean Glucose
CGM-measured mean glucose
Measured: 13 weeks
CGM Time Below 70
CGM-measured % below 70 mg/dL
Measured: 13 weeks
CGM Time Below 54
CGM-measured % below 54 mg/dL
Measured: 13 weeks
CGM Time in Range 70-140 mg/dL
CGM-measured % in range 70-140 mg/dL
Measured: 13 weeks
Coefficient of Variation
CGM measured glucose variability measured with the coefficient of variation (CV)
Measured: 13 weeks
Standard Deviation
CGM measured glucose variability measured with the standard deviation (SD)
Measured: 13 weeks
CGM Time Below 60
CGM-measured % below 60 mg/dL
Measured: 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)
Measured: 13 weeks
CGM Hypoglycemia Events
CGM-measured events of at least 15 consecutive minutes <70 mg/dL
Measured: 13 weeks
CGM Time >250
CGM-measured % >250 mg/dL
Measured: 13 weeks
CGM Time >300
CGM-measured % >300 mg/dL
Measured: 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)
Measured: 13 weeks
HbA1c at 13 Weeks
HbA1c at 13 weeks.
Measured: 13 weeks
HbA1c <7.0% at 13 Weeks
HbA1c <7.0% at 13 weeks.
Measured: 13 weeks
HbA1c <7.5% at 13 Weeks
HbA1c <7.5% at 13 weeks.
Measured: 13 weeks
HbA1c Change From Baseline to 13 Weeks >0.5%
HbA1c change from baseline to 13 weeks >0.5%.
Measured: 13 weeks
HbA1c Change From Baseline to 13 Weeks >1.0%
HbA1c change from baseline to 13 weeks >1.0%.
Measured: 13 weeks
HbA1c Relative Change From Baseline to 13 Weeks >10%
HbA1c relative change from baseline to 13 weeks >10%.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 13 weeks
Clarke Hypoglycemia Awareness Scores
Clarke Hypoglycemia Awareness Scores (0-7 score with higher scores associated with impaired awareness)
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 13 weeks
System Usability Scores (SUS)
System Usability Scores (SUS)-composite score from 0 to 100 with higher scores indicating better perceived usability
Measured: 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.
Measured: 13 weeks
Total Daily Insulin
Total Daily Insulin (units/kg)
Measured: 13 weeks
Basal:Bolus Insulin Ratio
Basal:Bolus Insulin Ratio.
Measured: 13 weeks
Weight
Weight (kg)
Measured: 13 weeks
BMI
Body Mass Index (BMI) kg/m2
Measured: 13 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Jul 2018
- Study start17 Jan 2019
- Primary completion28 Feb 2020
- Study completion9 Mar 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Type 1 Diabetes MellitusStudies of the same condition, open and under way.
- More trials run by University of VirginiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- A randomized controlled trial of 3 months at home closed loop system vs. predictive-low glucose suspend.
- Masking
- None (open label)
- Enrolment
- 164 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Virginia
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Jaeb Center for Health Research, Tandem Diabetes Care, Inc., DexCom, Inc., Roche Diagnostics GmbH
- Responsible party
- Principal investigator, Sue Brown, University of Virginia
- Investigators
- Sue Brown, MD, Principal investigator, University of Virginia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03591354
- Sponsor's protocol ID
- DCLP3 Extension
- Other IDs
- UC4DK108483
- Status last verified
- Aug 2022
- First submitted
- 19 Jun 2018
- Last updated
- 31 Aug 2022
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- Yes: Will follow the NIH Data Sharing Policy and Implementation Guidance on sharing research resources for research purposes to qualified individuals within the scientific community.
Publications
Bilionis I, Berrios RC, de Arriba Munoz A, Fernandez-Luque L, Castillo C. A framework for assessing algorithmic discrimination risks in training data: a case of pediatric type 1 diabetes. JAMIA Open. 2026 Jul 14;9(4):ooag125. doi: 10.1093/jamiaopen/ooag125. eCollection 2026 Aug.
PubMed 42459945Levy CJ, O'Malley G, Raghinaru D, Kudva YC, Laffel LM, Pinsker JE, Lum JW, Brown SA; iDCL Trial Research Group. Insulin Delivery and Glucose Variability Throughout the Menstrual Cycle on Closed Loop Control for Women with Type 1 Diabetes. Diabetes Technol Ther. 2022 May;24(5):357-361. doi: 10.1089/dia.2021.0431. Epub 2022 Feb 21.
PubMed 35099294
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Extension Study of t:Slim X2 With Control-IQ Technology
- ClinicalTrials.gov ID
- NCT03591354
- Acronym / sponsor ID
- DCLP3 Extension
- Conditions
- Type 1 Diabetes Mellitus
- Keywords
- Artificial Pancreas (AP), Type 1 Diabetes Mellitus, Insulin Pump, Continuous Glucose Monitor (CGM), Closed Loop Control (CLC), Sensor-Augmented Pump (SAP)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 164 participants (actual)
- Lead sponsor
- University of VirginiaUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Jaeb Center for Health Research, Tandem Diabetes Care, Inc., DexCom, Inc., Roche Diagnostics GmbH
- Study start
- 17 Jan 2019 (actual)
- Primary completion
- 28 Feb 2020 (actual)
- Study completion
- 9 Mar 2020 (actual)
- First posted
- 19 Jul 2018 (actual)
- Results
- Posted 25 Aug 2022
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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 design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- A randomized controlled trial of 3 months at home closed loop system vs. predictive-low glucose suspend.
| Arm | Type | Receives |
|---|---|---|
| Closed Loop Control (CLC) | Experimental | Device: t:slim X2 with Control-IQ Technology & Dexcom G6 CGMParticipants randomized to the closed loop control (CLC) arm will use the t:slim X2 with Control-IQ Technology \& Dexcom G6 Continuous Glucose Monitor (CGM) for 3 months. Objective 1: This arm is participants who had 6 months of CLC in the primary trial (DCLP3 Pivotal Trial) Objective 2: This arm is participants who had 6 months of sensor-augmented pump (SAP) in the primary trial (DCLP3 Pivotal Trial) Objective 3: This arm is participants who had 3 months of CLC in the extension trial (DCLP3 Extension) will continue use of the Control-IQ Technology \& Dexcom G6 CGM until the product is commercially available. |
| Predictive-Low Glucose Suspend (PLGS) | Active comparator | Device: t:slim X2 with Basal-IQ & Dexcom G6 CGMParticipants randomized to Predictive-Low Glucose Suspend (PLGS) will use the t:slim X2 with Basal-IQ \& Dexcom G6 CGM for 3 months. Objective 1: This arm is participants who had 6 months of PLGS in the primary trial (DCLP3 Pivotal Trial) Objective 2: This arm is not applicable to objective 2 Objective 3: This arm is participants who had 3 months of PLGS in the extension trial (DCLP3 Extension) will continue use of the Control-IQ Technology \& Dexcom G6 CGM until the product is commercially available. |
Who may qualify
- Ages
- 14 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Successful completion of the original 6-month RCT within the prior 14 days
- For females, not currently known to be pregnant. If female and sexually active, must agree to use a form of contraception to prevent pregnancy while a participant in the study. A negative urine pregnancy test will be required for all females of child-bearing potential. Participants who become pregnant will be discontinued from the study. Also, participants who during the study develop and express the intention to become pregnant within the timespan of the study will be discontinued.
- For participants <18 years old, living with one or more parent/legal guardian knowledgeable about emergency procedures for severe hypoglycemia and able to contact the participant in case of an emergency.
- Willingness to not use a personal CGM for the duration of the study
- Investigator has confidence that the participant can successfully operate all study devices and is capable of adhering to the protocol
Key exclusion criteria (5 listed)
- Concurrent use of any non-insulin glucose-lowering agent other than metformin (including GLP-1 agonists, Symlin, DPP-4 inhibitors, SGLT-2 inhibitors, sulfonylureas).
- Hemophilia or any other bleeding disorder
- A condition, which in the opinion of the investigator or designee, would put the participant or study at risk
- Participation in another pharmaceutical or device trial at the time of enrollment or during the study
- Employed by, or having immediate family members employed by Tandem Diabetes Care, Inc., Dexcom, Inc., or TypeZero Technologies, LLC, or having a direct supervisor at place of employment who is also directly involved in conducting the clinical trial (as a study investigator, coordinator, etc.); or having a first-degree relative who is directly involved in conducting the clinical trial
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| t:slim X2 with Control-IQ Technology & Dexcom G6 CGMParticipants will use the Tandem t:slim X2 insulin pump with Control-IQ Technology \& Dexcom G6 CGM for 3 months. | Device | Closed Loop Control (CLC) |
| t:slim X2 with Basal-IQ & Dexcom G6 CGMParticipants will use a Tandem t:slim X2 insulin pump with Basal-IQ and a study CGM (Dexcom G6) for 3 months. | Device | Predictive-Low Glucose Suspend (PLGS) |
Primary outcome
Time in Target Range
Time frame: 13 weeks
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.
36 secondary outcomes
CGM Time Above 180
Time frame: 13 weeks
CGM Mean Glucose
Time frame: 13 weeks
CGM Time Below 70
Time frame: 13 weeks
CGM Time Below 54
Time frame: 13 weeks
CGM Time in Range 70-140 mg/dL
Time frame: 13 weeks
Coefficient of Variation
Time frame: 13 weeks
Standard Deviation
Time frame: 13 weeks
CGM Time Below 60
Time frame: 13 weeks
LBGI
Time frame: 13 weeks
CGM Hypoglycemia Events
Time frame: 13 weeks
CGM Time >250
Time frame: 13 weeks
CGM Time >300
Time frame: 13 weeks
HBGI
Time frame: 13 weeks
HbA1c at 13 Weeks
Time frame: 13 weeks
HbA1c <7.0% at 13 Weeks
Time frame: 13 weeks
HbA1c <7.5% at 13 Weeks
Time frame: 13 weeks
HbA1c Change From Baseline to 13 Weeks >0.5%
Time frame: 13 weeks
HbA1c Change From Baseline to 13 Weeks >1.0%
Time frame: 13 weeks
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
Time frame: 13 weeks
HFS-II Adult
Time frame: 13 weeks
HFS-II Teen
Time frame: 13 weeks
HFS-II Parents
Time frame: 13 weeks
Hyperglycemia Avoidance Scale
Time frame: 13 weeks
Diabetes Distress Scale
Time frame: 13 weeks
Hypoglycemia Confidence Scale
Time frame: 13 weeks
Clarke Hypoglycemia Awareness Scores
Time frame: 13 weeks
INSPIRE Survey Scores- Adults
Time frame: 13 weeks
INSPIRE Survey Scores- Teens
Time frame: 13 weeks
INSPIRE Survey Scores- Parents
Time frame: 13 weeks
System Usability Scores (SUS)
Time frame: 13 weeks
Technology Acceptance Questionnaire
Time frame: 13 weeks
Total Daily Insulin
Time frame: 13 weeks
Basal:Bolus Insulin Ratio
Time frame: 13 weeks
Weight
Time frame: 13 weeks
BMI
Time frame: 13 weeks
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Aug 2022.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 42459945Bilionis I, Berrios RC, de Arriba Munoz A, Fernandez-Luque L, Castillo C. A framework for assessing algorithmic discrimination risks in training data: a case of pediatric type 1 diabetes. JAMIA Open. 2026 Jul 14;9(4):ooag125. doi: 10.1093/jamiaopen/ooag125. eCollection 2026 Aug.
- Derived from this study: PubMed 35099294Levy CJ, O'Malley G, Raghinaru D, Kudva YC, Laffel LM, Pinsker JE, Lum JW, Brown SA; iDCL Trial Research Group. Insulin Delivery and Glucose Variability Throughout the Menstrual Cycle on Closed Loop Control for Women with Type 1 Diabetes. Diabetes Technol Ther. 2022 May;24(5):357-361. doi: 10.1089/dia.2021.0431. Epub 2022 Feb 21.
- Individual participant dataSharing planned: Yes. Will follow the NIH Data Sharing Policy and Implementation Guidance on sharing research resources for research purposes to qualified individuals within the scientific community.
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Continuous Glucose Monitoring, Type 1 Diabetes
RecruitingObservational study
Estimated Risk of Preeclampsia in the First Trimester and Its Association With Subclinical Atherosclerosis and Cardiovascular Risk in Women With Type 1 Diabetes
Type 1 Diabetes, Preeclampsia
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Sue Brown, MD principal investigator
University of Virginia
7 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing t:slim X2 with Basal-IQ & Dexcom G6 CGM in people with Type 1 Diabetes Mellitus, run by University of Virginia at 7 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 31 Aug 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 7 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 25 Aug 2022). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time in Target Range (time frame: 13 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03591354, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Aug 2022.