Evaluation of Fiasp® (Fast Acting Insulin Aspart) in 670G Hybrid Closed-Loop Therapy

Study Overview
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Brief Summary
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This is a pilot outpatient study conducted at Stanford to obtain preliminary data on how Fiasp® works in a closed-loop system and to determine if any changes need to be made to the 670G pump to optimize the use of Fiasp®.

Detailed Description
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This will be a randomized cross-over blinded study and to see how the 670G pump responds to the introduction of Fiasp® insulin. Subjects enrolled in the study will have a 2 week period of optimization with weekly assessments of their Carelink download before entering the blinded phase of the study. They will use their usual home insulin during the optimization phase. They will then be started on their first blinded insulin (aspart or Fiasp®) which they will use for 2 weeks, before they cross-over to the other insulin.

Official Title
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Evaluation of Fiasp® (Fast Acting Insulin Aspart) in 670G Hybrid Closed-Loop Therapy: To Assess How the 670G System Adapts to the Introduction of Fiasp® Insulin

Conditions
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Diabetes Mellitus, Type 1

Intervention / Treatment
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* Drug: Fiasp
* Drug: Novolog


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical diagnosis of type 1 diabetes and using 670G pump for at least 1 month, and willing to have the 670G pump downloaded into a Carelink Clinical research database. The diagnosis of type 1 diabetes is based on the investigator's judgment; C-peptide level and antibody determinations are not needed. Age ≥18 years Using Novolog or Fiasp® insulin at time of enrollment Willing to use Fiasp® insulin Total daily insulin dose is at least 0.3 units/kg/day Usual carbohydrate intake is at least 60 grams a day, and willing to have at least 25 grams of carbohydrates for breakfast For females, not currently known to be pregnant An understanding of and willingness to follow the protocol and sign the informed consent Willing to have photographs taken of their infusion sites Willing to download their 670G pump every 1-2 weeks to a research Carelink account Willingness to answer a brief online questionnaire every 2 weeks Must be able to understand spoken or written English For subjects participating in Part 2 of this study they will need to be using Fiasp® as part of their usual care Hemoglobin A1c between 6 and 10% at the time of enrollment Exclusion Criteria: Pregnant or lactating females No hypoglycemic seizure or loss of consciousness in the past 6 months Severe episode of DKA in the 6 months prior to study enrollment that was unrelated to an infusion set failure No known cardiovascular events in the last 6 months No active proliferative diabetic retinopathy Known tape allergies Current treatment for a seizure disorder Cystic fibrosis Active infection A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol Inpatient psychiatric treatment in the past 6 months Presence of a known adrenal disorder If on antihypertensive, thyroid, anti-depressant or lipid lowering medication, with lack of stability on the medication for the past 2 months prior to enrollment in the study Abuse of alcohol Dialysis or renal failure Known eGFR <60% Note: Adequately treated thyroid disease and celiac disease do not exclude subjects from enrollment.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Subjects will be randomly assigned to start with either Fiasp insulin or Novolog insulin. After 2 weeks, they will start the previously unassigned insulin and continue using it for another 2 weeks.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Fiasp then Novolog<br>Following a 2-week run-in period for pump-setting adjustments and monitoring, participants 1 will use Fiasp insulin for 2 weeks, followed by Novolog insulin for 2 weeks. Both the subject and the investigator will be blinded to which group the subject is assigned. | Drug: Fiasp<br>* Fiasp insulin will be used for 2 weeks with the 670G hybrid closed-loop system<br>* Other names: Fast Acting Insulin Aspart;Drug: Novolog<br>* Novolog insulin will be used for 2 weeks with the 670G hybrid closed-loop system<br>* Other names: Insulin Aspart;|
| Experimental: Novolog then Fiasp<br>Following a 2-week run-in period for pump-setting adjustments and monitoring, participants 1 will use Novolog insulin for 2 weeks, followed by Fiasp insulin for 2 weeks. Both the subject and the investigator will be blinded to which group the subject is assigned. | Drug: Fiasp<br>* Fiasp insulin will be used for 2 weeks with the 670G hybrid closed-loop system<br>* Other names: Fast Acting Insulin Aspart;Drug: Novolog<br>* Novolog insulin will be used for 2 weeks with the 670G hybrid closed-loop system<br>* Other names: Insulin Aspart;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Time in Range: Sensor Glucose Values Between 70-180 mg/dl | Measured as percentage of time in range (days). | 7 days (during 2nd half of 2-week intervention period) | 
| Percentage of Time in Range: Sensor Glucose Readings <70 mg/dl | Percentage of time in range (days) as a measure of hypoglycemia. | 7 days (during 2nd half of 2-week intervention period) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean Sensor Glucose in mg/dl | Mean sensor data over the second week of using a randomized, blinded insulin. | 7 days (during 2nd half of 2-week intervention period) |