TerminatedNCT02701257Updated Nov 18, 2019Results posted

The iLet Introduction Study: A Feasibility Study of the iLet, a Fully Integrated Bihormonal Bionic Pancreas

An interventional study of iPhone bionic pancreas and iLet bionic pancreas in Diabetes Mellitus Type 1, sponsored by Massachusetts General Hospital. Terminated at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2019-11-18.

Sponsored by Massachusetts General Hospital · Not applicable, Interventional, and Treatment

Why this study was terminated

The study was terminated prior to completing the planned cohorts and analysis because of problems with the infusion set resulting in inadequate insulin delivery

Phase: Not applicable
Study type: Interventional
Enrollment: 20
Allocation: Randomized
Ages: 18 Years and older
Sex: All

Study summary

This study will compare two different models of a wearable bionic pancreas device (the iPhone-based bionic pancreas vs. the iLet bionic pancreas) in adult participant with type 1 diabetes. Both bionic pancreas devices measure glucose levels every five minutes and then give insulin and/or glucagon automatically to regulate the blood glucose (BG).

Read the detailed description

The iPhone bionic pancreas has been used in earlier studies, during which volunteers used the system for up to 11 days at a time while living their normal lives at home and work. The iLet bionic pancreas has never been tested in humans. In this new study, volunteers will participate in a training visit to learn how both devices work. They will then use the iPhone-based BP for 1 day and the iLet BP for 1 day in random order using Lilly glucagon. They will then use the iLet BP for one additional day using Xeris Xerisol glucagon (a stable formulation of human glucagon).

A custom infusion set is required for this bihormonal system, to prevent future consumers from being able to accidentally swap their insulin and glucagon reservoirs and infusion sets, which could be potentially fatal. Previous experiments have demonstrated flaws in the infusion set design, requiring human experiments to be suspended and modifications to the infusion set be made. We believe the current infusion set has addressed these flaws by incorporating an anti-coring heel and a tri-beveled needle, and the infusion set sub-study is designed to isolate and study the infusion set function before further experiments using the iLet BP are conducted.

Conditions studied

Diabetes Mellitus Type 1

Browse trials for

Diabetes Mellitus, Type 1 3,522

Keywords

Bionic Pancreas
Insulin
Glucagon
Continuous Glucose Monitor

In context

Diabetes Mellitus, Type 1

3,522 studies on the registry are indexed under Diabetes Mellitus, Type 1; 577 are open to participants now.

This study's enrollment of 20 is below the median of 40 across 2,649 interventional studies indexed under Diabetes Mellitus, Type 1.

Browse Diabetes Mellitus, Type 1 studies →

Lead sponsor

Massachusetts General Hospital is the lead sponsor of 2,536 studies on the registry; 446 are open to participants now.

Of its 214 completed or terminated interventional studies of FDA-regulated products, 161 (75%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: All
Accepts healthy volunteers: No

Inclusion criteria

iPhone and iLet BP experiments

Age ≥ 18 years and have had clinical type 1 diabetes for at least one year
Diabetes managed using an insulin pump for ≥ 6 months
Prescription medication regimen stable for > 1 month (except for medications that will not affect the safety of the study and are not expected to affect any outcome of the study, in the judgment of the principal investigator)

iLet Infusion Set Sub-Study

Age ≥ 18 years and have had clinical type 1 diabetes for at least one year
Diabetes managed using an insulin pump for ≥ 6 months

Exclusion criteria

Exclusion Criteria:

iPhone and iLet BP experiments

Unable to provide informed consent (e.g. impaired cognition or judgment)
Unable to safely comply with study procedures and reporting requirements (e.g. impairment of vision or dexterity that prevents safe operation of the bionic pancreas, impaired memory, unable to speak and read English)
Current participation in another diabetes-related clinical trial that, in the judgment of the principal investigator, will compromise the results of this study or the safety of the subject
Pregnancy (positive urine HCG), breast feeding, plan to become pregnant in the immediate future, or sexually active without use of contraception
Current alcohol abuse (intake averaging > 3 drinks daily in last 30 days), use of marijuana within 1 month of enrollment, or other substance abuse (use within the last 6 months of controlled substances other than marijuana without a prescription)
Unwilling or unable to refrain on the study days from:acetaminophen in any form, use of marijuana, use of drugs that may dull the sensorium, reduce sensitivity to symptoms of hypoglycemia, or hinder decision making during the period of participation in the study (use of beta blockers will be allowed as long as the dose is stable and the subject does not meet the criteria for hypoglycemia unawareness while taking that stable dose, but use of benzodiazepines or narcotics, even if by prescription, may be excluded according to the judgment of the principal investigator)
History of liver disease that is expected to interfere with the anti-hypoglycemia action of glucagon (e.g. liver failure or cirrhosis). Other liver disease (i.e. active hepatitis, steatosis, active biliary disease, any tumor of the liver, hemochromatosis, glycogen storage disease) may exclude the subject if it causes significant compromise to liver function or may do so in an unpredictable fashion.
Renal failure on dialysis
Personal history of cystic fibrosis, pancreatitis, pancreatic tumor, or any other pancreatic disease besides type 1 diabetes
Any known history of coronary artery disease including, but not limited to, history of myocardial infarction, stress test showing ischemia, history of angina, or history of intervention such as coronary artery bypass grafting, percutaneous coronary intervention, or enzymatic lysis of a presumed coronary occlusion)
Congestive heart failure (established history of CHF, lower extremity edema, paroxysmal nocturnal dyspnea, or orthopnea)
History of TIA or stroke
Seizure disorder, history of any non-hypoglycemic seizure within the last two years, or ongoing treatment with anticonvulsants
History of hypoglycemic seizures (grand-mal) or coma in the last year
History of pheochromocytoma: fractionated metanephrines will be tested in patients with history increasing the risk for a catecholamine secreting tumor: Episodic or treatment refractory (requiring 4 or more medications to achieve normotension) hypertension, Paroxysms of tachycardia, pallor, or headache, Personal or family history of MEN 2A, MEN 2B, neurofibromatosis, or von Hippel-Lindau disease
History of adrenal disease or tumor
Hypertension with systolic BP ≥160 mm Hg or diastolic BP ≥100 despite treatment
Untreated or inadequately treated mental illness (indicators would include symptoms such as psychosis, hallucinations, mania, and any psychiatric hospitalization in the last year), or treatment with anti-psychotic medications that are known to affect glucose regulation.
Electrically powered implants (e.g. cochlear implants, neurostimulators) that might be susceptible to RF interference
History of adverse reaction to glucagon (including allergy) besides nausea and vomiting
Established history of allergy or severe reaction to adhesive or tape that must be used in the study
Use of oral (e.g. thiazolidinediones, biguanides, sulfonylureas, glitinides, DPP-4 inhibitors, SGLT-2 inhibitors) anti-diabetic medications
Hemoglobin \< 12 g/dl
Any factors that, in the opinion of the principal investigator would interfere with the safe completion of the study

iLet Infusion Set Sub-Study

Unable to provide informed consent (e.g. impaired cognition or judgment)
Unable to safely comply with study procedures and reporting requirements (e.g. impairment of vision or dexterity that prevents safe operation of their insulin pump, impaired memory, unable to speak and read English)
Pregnancy (positive urine HCG), breast feeding, plan to become pregnant in the immediate future, or sexually active without use of contraception
Hemoglobin \< 11 g/dl
Unable to establish IV access, or subject reports difficult IV access in the past
History of allergy or severe reaction to adhesive or tape that must be used in the study

Study design

Phase: Not applicable
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover assignment
Masking: None (open label)
Enrollment: 20 participants (actual)

Study arms

Active comparator
iPhone bionic pancreas - Lilly glucagon
iPhone based bionic pancreas using insulin lispro and Lilly glucagon. These visits will be conducted separately from the infusion set sub-study visits.
Device: iPhone bionic pancreas · Drug: Lilly glucagon
Experimental
iLet bionic pancreas - Lilly glucagon
iLet Bionic Pancreas using using insulin lispro and Lilly glucagon. These visits will be conducted separately from the infusion set sub-study visits.
Device: iLet bionic pancreas · Drug: Lilly glucagon
Experimental
iLet bionic pancreas - Xerisol glucagon
iLet Bionic Pancreas using using insulin lispro and Xeris Xerisol glucagon. These visits will be conducted separately from the infusion set sub-study visits.
Device: iLet bionic pancreas · Drug: Xeris Xerisol glucagon
Experimental
iLet infusion set
The infusion set sub-study will be testing just the experimental iLet infusion set in a crossover with the contact detach infusion set. These visits will be conducted separately from the iPhone and iLet bionic pancreas visits.
Device: iLet infusion set
Active comparator
Contact Detach infusion set
The infusion set sub-study will be testing just the experimental iLet infusion set in a crossover with the contact detach infusion set. These visits will be conducted separately from the iPhone and iLet bionic pancreas visits.
Device: Contact Detach infusion set

Interventions

DeviceiPhone bionic pancreas
An experimental device composed of three parts: a continuous glucose monitor, control algorithms running on an iPhone, and drug delivery using Tandem insulin pumps
DeviceiLet bionic pancreas
An experimental device that combines the functions of the iPhone-based bionic pancreas into one device.
DrugXeris Xerisol glucagon
A stabilized formulation of human glucagon in a solvent based primarily composed of dimethyl sulfoxide (DMSO) that has prolonged stability and can be used for multiple days in a pump
Also known as: Xeris glucagon
DrugLilly glucagon
An aqueous formulation of human glucagon with limited stability that must be changed daily
Also known as: glucagon
DeviceiLet infusion set
The infusion set sub-study will be studying the experimental iLet infusion set in a cross-over with the Contact Detach infusion set. These visits will be conducted separately from the iPhone and iLet BP visits.
DeviceContact Detach infusion set
The infusion set sub-study will be studying the experimental iLet infusion set in a cross-over with the Contact Detach infusion set. These visits will be conducted separately from the iPhone and iLet BP visits.

What researchers measure

Primary outcomes

Average Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Aggregate of Both Insulin and Glucagon Doses)
Average percent dose amounts calculated by the bionic pancreas control algorithm that are successfully delivered by the pump (aggregate of both insulin and glucagon doses) - primary outcome for iPhone-based BP using Lilly glucagon vs. iLet BP using Lilly glucagon
Time frame: 8 hours
Average Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Glucagon Doses).
Average percent dose amounts calculated by the bionic pancreas control algorithm that are successfully delivered by the pump (glucagon doses) - - primary outcome for iLet BP using Lilly glucagon vs. iLet BP using Xeris Xerisol glucagon
Time frame: 8 hours
Insulin Area Under the Curve in the 3.5 Hours Following the Insulin Bolus
This applies only to the infusion set sub-study
Time frame: 3.5 hours following insulin bolus

Secondary outcomes

Average Continuous Glucose Monitor (CGM) Glucose
The average glucose according to continuous glucose monitor readings. This only applies to the iPhone vs. iLet BP experiments.
Time frame: 8 hours
Percentage of Time in Each of the Following Ranges: < 50 mg/dl, < 60 mg/dl, <70 mg/dl, 70-120 mg/dl, 70-180 mg/dl, >180 mg/dl, >250 mg/dl
Percentage of time subjects spent in each of these ranges based on continuous glucose monitor readings. This only applies to the iPhone vs iLet BP visits.
Time frame: 8 hours
Number of Subjects With Mean CGM Glucose < 154 mg/dl
The number of subjects who achieved a mean CGM glucose \< 154 mg/dl, which correlates to an estimated hemoglobin a1c of 7%, which is the ADA goal for therapy. This applies only to the iPhone vs iLet BP experiments
Time frame: 8 hours
Number of Severe Hypoglycemic Events (Subject Unable to Self-treat, Requiring the Assistance of Another Person)
The number of severe hypoglycemic events subjects experience. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Average Percent Insulin Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.
The average percentage of successfully delivered insulin doses. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Average Percent Glucagon Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.
The average percentage of successfully delivered glucagon doses. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Average Percent Insulin Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.
The average percentage of successfully issued insulin doses that are then delivered successfully by the pump. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Average Percent Glucagon Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That a Successfully Delivered by the Pump.
The average percentage of successfully issued glucagon doses that are then delivered successfully by the pump. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Average Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally in All Respects Based on Real-time CGM Data (New CGM Glucose Reading Captured, Dose Calculated, Dose Issued to Pumps
The percentage of time (measured in 5 minute "steps") that the bionic pancreas is working, indicated by the presence of a CGM reading, a successful dose calculation and successful issuing of a dose. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Average Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally With or Without a New CGM Glucose Reading Captured (Dose Calculated, Dose Issued to Pumps).
The percentage of time (measured in 5 minute "steps") that the bionic pancreas is working even without a CGM reading being present, indicated by a successful dose calculation and successful issuing of a dose. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
CGM Reliability Index, Calculated as Percent of Possible Values Actually Recorded by CGM.
A measure of CGM reliability, indicating the percentage of values the CGM displayed out of the total values it should have displayed in that time. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Glucagon Total Delivery Per kg of Body Mass.
The average total glucagon delivered by the bionic pancreas. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Insulin Total Delivery Per kg of Body Mass.
The average total insulin delivered by the bionic pancreas. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Number of Episodes of Symptomatic Hypoglycemia.
Number of time subjects experienced symptoms of hypoglycemia and reported that to study staff. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Total Grams of Carbohydrate Taken for Hypoglycemia.
The total grams of carbohydrates given to subjects for treatment of hypoglycemia. This applies only to the iPhone vs iLet BP experiments.
Time frame: 8 hours
Difference in Mean Nausea From VAS During the Study
This applies only the iPhone vs. iLet BP experiments. Subjects were given a visual analog scale measuring 100 mm and asked to draw a line to indicate their level of nausea at timepoints during the study with 100 being the "worst possible nausea" and 0 being "no nausea".
Time frame: 8 hours
Average Insulin Infusion Site Pain From VAS
This applies to the iPhone vs. iLet BP experiments and the infusion set sub-study experiments. Subjects were given a visual analog scale measuring 100 mm and asked to draw a line to indicate their level of pain at timepoints during the study with 100 being the "worst possible pain" and 0 being "no pain".
Time frame: 8 hours
Difference in Local Erythema and Edema According to the Draize Scale
This applies to the iPhone vs. iLet BP experiments and the infusion set sub-study experiments. The draize scale assess erythema, eschar and edema using a score from 0-4, with 4 meaning a worse outcome.
Time frame: 8 hours
Number of Unscheduled Infusion Set Replacements.
This applies to the iPhone vs. iLet BP experiments and the infusion set sub-study experiments.
Time frame: 8 hours
Number of Unscheduled CGM Sensor Changes.
This applies only to the iPhone vs. iLet BP experiments
Time frame: 8 hours
Insulin Area Under the Curve During the Initial 90 Minute Fasted Period
This applies only to the infusion set sub-study
Time frame: 8 hours
Mean Insulin Levels During the Initial 90 Minute Fasted Period
This applies only to the infusion set sub-study
Time frame: 8 hours
Difference Between Insulin Levels at Baseline and at 90 Minutes
This applies only to the infusion set sub-study
Time frame: 8 hours
Tmax After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
T 1/2 Max After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
C Max After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
AUC in the First 30 Minutes After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
AUC in the First 60 Minutes After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
AUC in the First 90 Minutes After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
Terminal Half Life After the Insulin Dose
This applies only to the infusion set sub-study
Time frame: 8 hours
Difference Between the Fasted PG Value and the PG Value at 90 Minutes
This applies only to the infusion set sub-study
Time frame: Baseline Fasted State and 90 Minutes
Difference in the PG Prior to the Meal and Peak Post-prandial Glucose
This applies only to the infusion set sub-study
Time frame: Pre-meal PG value and peak PG value during the 3.5 hours following the meal.
PG AUC in the 3.5 Hours Following the Meal
This applies only to the infusion set sub-study
Time frame: 3.5 hours following the meal

Results

Posted Nov 18, 2019

Limitations and caveats

The original planned experiments and infusion set sub study were terminated early due to infusion site failures before the planned cohorts were completed. Changes to the infusion set design will be implemented prior to initiating any future studies.

Participant flow

Participant flow — Overall Study
Milestone	iPhone BP First, Then iLet BP (Lilly gLucagon)	iLet BP First, Then iPhone BP (Lilly Glucagon)	iLet Infusion Set First, Then Contact Detach	Contact Detach Infusion Set First, Then iLet Infusion Set
Started	6	6	4	4
Completed	6	3	3	1
Not completed	0	3	1	3

Outcome measures

PrimaryAverage Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Aggregate of Both Insulin and Glucagon Doses)

Average percent dose amounts calculated by the bionic pancreas control algorithm that are successfully delivered by the pump (aggregate of both insulin and glucagon doses) - primary outcome for iPhone-based BP using Lilly glucagon vs. iLet BP using Lilly glucagon

Time frame:: 8 hours
Reported as:: Mean · percentage of doses delivered

Average Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Aggregate of Both Insulin and Glucagon Doses)
percentage of doses delivered	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Aggregate of Both Insulin and Glucagon Doses)	94.6 ± 9.2	95.0 ± 12.3	—	—	—

PrimaryAverage Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Glucagon Doses).

Average percent dose amounts calculated by the bionic pancreas control algorithm that are successfully delivered by the pump (glucagon doses) - - primary outcome for iLet BP using Lilly glucagon vs. iLet BP using Xeris Xerisol glucagon

Time frame:: 8 hours
Reported as:: Mean · percentage of doses

Average Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Glucagon Doses).
percentage of doses	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump (Glucagon Doses).	96.6 ± 6.8	100.0 ± 0.5	—	—	—

PrimaryInsulin Area Under the Curve in the 3.5 Hours Following the Insulin Bolus

This applies only to the infusion set sub-study

Time frame:: 3.5 hours following insulin bolus

No measurements were reported for this outcome.

SecondaryAverage Continuous Glucose Monitor (CGM) Glucose

The average glucose according to continuous glucose monitor readings. This only applies to the iPhone vs. iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · mg/dl

Average Continuous Glucose Monitor (CGM) Glucose
mg/dl	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Continuous Glucose Monitor (CGM) Glucose	179.2 ± 37.5	251.2 ± 80.0	—	—	—

SecondaryPercentage of Time in Each of the Following Ranges: < 50 mg/dl, < 60 mg/dl, <70 mg/dl, 70-120 mg/dl, 70-180 mg/dl, >180 mg/dl, >250 mg/dl

Percentage of time subjects spent in each of these ranges based on continuous glucose monitor readings. This only applies to the iPhone vs iLet BP visits.

Time frame:: 8 hours
Reported as:: Mean · percentage of time

Percentage of Time in Each of the Following Ranges: < 50 mg/dl, < 60 mg/dl, <70 mg/dl, 70-120 mg/dl, 70-180 mg/dl, >180 mg/dl, >250 mg/dl
percentage of time	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
CGM glucose < 60	0.0 ± 0.0	0.36 ± 1.07	—	—	—
CGM glucose > 180	39.0 ± 24.5	67.5 ± 21.3	—	—	—

SecondaryNumber of Subjects With Mean CGM Glucose < 154 mg/dl

The number of subjects who achieved a mean CGM glucose \< 154 mg/dl, which correlates to an estimated hemoglobin a1c of 7%, which is the ADA goal for therapy. This applies only to the iPhone vs iLet BP experiments

Time frame:: 8 hours
Reported as:: Count of participants · Participants

Number of Subjects With Mean CGM Glucose < 154 mg/dl
Participants	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Number of Subjects With Mean CGM Glucose < 154 mg/dl	1	1	—	—	—

SecondaryNumber of Severe Hypoglycemic Events (Subject Unable to Self-treat, Requiring the Assistance of Another Person)

The number of severe hypoglycemic events subjects experience. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Number · events

Number of Severe Hypoglycemic Events (Subject Unable to Self-treat, Requiring the Assistance of Another Person)
events	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Number of Severe Hypoglycemic Events (Subject Unable to Self-treat, Requiring the Assistance of Another Person)	0	0	—	—	—

SecondaryAverage Percent Insulin Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.

The average percentage of successfully delivered insulin doses. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of doses

Average Percent Insulin Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.
percentage of doses	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent Insulin Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.	94.0 ± 10.7	95.8 ± 13.3	—	—	—

SecondaryAverage Percent Glucagon Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.

The average percentage of successfully delivered glucagon doses. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of doses

Average Percent Glucagon Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.
percentage of doses	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent Glucagon Dose Amounts Calculated by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.	96.6 ± 6.8	100.0 ± 0.5	—	—	—

SecondaryAverage Percent Insulin Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.

The average percentage of successfully issued insulin doses that are then delivered successfully by the pump. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of doses

Average Percent Insulin Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.
percentage of doses	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent Insulin Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That Are Successfully Delivered by the Pump.	98.5 ± 5.5	96.1 ± 13.1	—	—	—

SecondaryAverage Percent Glucagon Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That a Successfully Delivered by the Pump.

The average percentage of successfully issued glucagon doses that are then delivered successfully by the pump. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of doses

Average Percent Glucagon Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That a Successfully Delivered by the Pump.
percentage of doses	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent Glucagon Dose Amounts Successfully Issued to the Pump by the Bionic Pancreas Control Algorithm That a Successfully Delivered by the Pump.	96.6 ± 6.8	100.0 ± 0.5	—	—	—

SecondaryAverage Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally in All Respects Based on Real-time CGM Data (New CGM Glucose Reading Captured, Dose Calculated, Dose Issued to Pumps

The percentage of time (measured in 5 minute "steps") that the bionic pancreas is working, indicated by the presence of a CGM reading, a successful dose calculation and successful issuing of a dose. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of 5 minute steps

Average Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally in All Respects Based on Real-time CGM Data (New CGM Glucose Reading Captured, Dose Calculated, Dose Issued to Pumps
percentage of 5 minute steps	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally in All Respects Based on Real-time CGM Data (New CGM Glucose Reading Captured, Dose Calculated, Dose Issued to Pumps	88.9 ± 0.073	75.1 ± 0.196	—	—	—

SecondaryAverage Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally With or Without a New CGM Glucose Reading Captured (Dose Calculated, Dose Issued to Pumps).

The percentage of time (measured in 5 minute "steps") that the bionic pancreas is working even without a CGM reading being present, indicated by a successful dose calculation and successful issuing of a dose. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of 5 minutes steps

Average Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally With or Without a New CGM Glucose Reading Captured (Dose Calculated, Dose Issued to Pumps).
percentage of 5 minutes steps	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Percent of 5 Minute Steps During Which the Bionic Pancreas is Functioning Nominally With or Without a New CGM Glucose Reading Captured (Dose Calculated, Dose Issued to Pumps).	94.6 ± 0.054	99.8 ± 0.004	—	—	—

SecondaryCGM Reliability Index, Calculated as Percent of Possible Values Actually Recorded by CGM.

A measure of CGM reliability, indicating the percentage of values the CGM displayed out of the total values it should have displayed in that time. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · percentage of CGM values

CGM Reliability Index, Calculated as Percent of Possible Values Actually Recorded by CGM.
percentage of CGM values	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
CGM Reliability Index, Calculated as Percent of Possible Values Actually Recorded by CGM.	94.1 ± 0.06	75.1 ± 0.19	—	—	—

SecondaryGlucagon Total Delivery Per kg of Body Mass.

The average total glucagon delivered by the bionic pancreas. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · mcg/kg

Glucagon Total Delivery Per kg of Body Mass.
mcg/kg	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Glucagon Total Delivery Per kg of Body Mass.	0.60 ± 0.84	1.12 ± 1.71	—	—	—

SecondaryInsulin Total Delivery Per kg of Body Mass.

The average total insulin delivered by the bionic pancreas. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Mean · units/kg

Insulin Total Delivery Per kg of Body Mass.
units/kg	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Insulin Total Delivery Per kg of Body Mass.	0.22 ± 0.07	0.23 ± 0.07	—	—	—

SecondaryNumber of Episodes of Symptomatic Hypoglycemia.

Number of time subjects experienced symptoms of hypoglycemia and reported that to study staff. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Number · number of episodes

Number of Episodes of Symptomatic Hypoglycemia.
number of episodes	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Number of Episodes of Symptomatic Hypoglycemia.	0	0	—	—	—

SecondaryTotal Grams of Carbohydrate Taken for Hypoglycemia.

The total grams of carbohydrates given to subjects for treatment of hypoglycemia. This applies only to the iPhone vs iLet BP experiments.

Time frame:: 8 hours
Reported as:: Number · number of grams of carbohydrates

Total Grams of Carbohydrate Taken for Hypoglycemia.
number of grams of carbohydrates	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Total Grams of Carbohydrate Taken for Hypoglycemia.	0	0	—	—	—

SecondaryDifference in Mean Nausea From VAS During the Study

This applies only the iPhone vs. iLet BP experiments. Subjects were given a visual analog scale measuring 100 mm and asked to draw a line to indicate their level of nausea at timepoints during the study with 100 being the "worst possible nausea" and 0 being "no nausea".

Time frame:: 8 hours
Reported as:: Mean · score on a scale

Difference in Mean Nausea From VAS During the Study
score on a scale	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Difference in Mean Nausea From VAS During the Study	3.47 ± 10.47	6.93 ± 15.29	—	—	—

SecondaryAverage Insulin Infusion Site Pain From VAS

This applies to the iPhone vs. iLet BP experiments and the infusion set sub-study experiments. Subjects were given a visual analog scale measuring 100 mm and asked to draw a line to indicate their level of pain at timepoints during the study with 100 being the "worst possible pain" and 0 being "no pain".

Time frame:: 8 hours
Reported as:: Mean · score on a scale

Average Insulin Infusion Site Pain From VAS
score on a scale	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Average Insulin Infusion Site Pain From VAS	1.49 ± 3.06	6.61 ± 13.04	—	0.54 ± 2.61	2.42 ± 9.98

SecondaryDifference in Local Erythema and Edema According to the Draize Scale

This applies to the iPhone vs. iLet BP experiments and the infusion set sub-study experiments. The draize scale assess erythema, eschar and edema using a score from 0-4, with 4 meaning a worse outcome.

Time frame:: 8 hours
Reported as:: Mean · score on a scale

Difference in Local Erythema and Edema According to the Draize Scale
score on a scale	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Difference in Local Erythema and Edema According to the Draize Scale	0 ± 0	0 ± 0	—	0 ± 0	0 ± 0

SecondaryNumber of Unscheduled Infusion Set Replacements.

This applies to the iPhone vs. iLet BP experiments and the infusion set sub-study experiments.

Time frame:: 8 hours
Reported as:: Number · number of infusion set changes

Number of Unscheduled Infusion Set Replacements.
number of infusion set changes	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Number of Unscheduled Infusion Set Replacements.	1	0	—	0	0

SecondaryNumber of Unscheduled CGM Sensor Changes.

This applies only to the iPhone vs. iLet BP experiments

Time frame:: 8 hours
Reported as:: Number · number of sensor changes

Number of Unscheduled CGM Sensor Changes.
number of sensor changes	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Number of Unscheduled CGM Sensor Changes.	0	0	—	—	—

SecondaryInsulin Area Under the Curve During the Initial 90 Minute Fasted Period

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryMean Insulin Levels During the Initial 90 Minute Fasted Period

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryDifference Between Insulin Levels at Baseline and at 90 Minutes

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryTmax After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryT 1/2 Max After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryC Max After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryAUC in the First 30 Minutes After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryAUC in the First 60 Minutes After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryAUC in the First 90 Minutes After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryTerminal Half Life After the Insulin Dose

This applies only to the infusion set sub-study

Time frame:: 8 hours

No measurements were reported for this outcome.

SecondaryDifference Between the Fasted PG Value and the PG Value at 90 Minutes

This applies only to the infusion set sub-study

Time frame:: Baseline Fasted State and 90 Minutes
Reported as:: Mean · mg/dl

Difference Between the Fasted PG Value and the PG Value at 90 Minutes
mg/dl	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Difference Between the Fasted PG Value and the PG Value at 90 Minutes	—	—	—	-3.7 ± 28.7	-6.7 ± 41.8

SecondaryDifference in the PG Prior to the Meal and Peak Post-prandial Glucose

This applies only to the infusion set sub-study

Time frame:: Pre-meal PG value and peak PG value during the 3.5 hours following the meal.
Reported as:: Mean · mg/dl

Difference in the PG Prior to the Meal and Peak Post-prandial Glucose
mg/dl	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
Difference in the PG Prior to the Meal and Peak Post-prandial Glucose	—	—	—	176.3 ± 88.2	73.9 ± 76.8

SecondaryPG AUC in the 3.5 Hours Following the Meal

This applies only to the infusion set sub-study

Time frame:: 3.5 hours following the meal
Reported as:: Mean · mg*min/dl

PG AUC in the 3.5 Hours Following the Meal
mg*min/dl	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach Infusion Set
PG AUC in the 3.5 Hours Following the Meal	—	—	—	15512740 ± 10050495	8359871 ± 5458714

Adverse events

Collected over During study visits up to 8 hours long. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
iPhone Bionic Pancreas - Lilly Glucagon	0/9 (0%)	0/9 (0%)	0/9 (0%)
iLet Bionic Pancreas - Lilly Glucagon	0/12 (0%)	0/12 (0%)	7/12 (58.3%)
iLet Bionic Pancreas - Xerisol Glucagon	—	—	—
iLet Infusion Set	0/5 (0%)	0/5 (0%)	0/5 (0%)
Contact Detach	0/7 (0%)	0/7 (0%)	0/7 (0%)

Most frequent other events

Most frequent other events
Event	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set	Contact Detach
HyperglycemiaEndocrine disorders	0/9	7/12	—	0/5	0/7

Baseline characteristics

The study was terminated and the iLet BP arm with Xeris glucagon was never conducted.

Age, Continuous
Age, Continuous(years)	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set First, Then Contact Detach	Contact Detach First, Then iLet Infusion Set	Total
Mean	38.6 ± 22.3	32.6 ± 17.9	—	48.8 ± 14.7	44.7 ± 17.7	39.7 ± 17.5

Sex: Female, Male
Sex: Female, Male(Participants)	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set First, Then Contact Detach	Contact Detach First, Then iLet Infusion Set	Total
Female	5	4	—	3	2	14
Male	1	2	—	1	2	6

Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set First, Then Contact Detach	Contact Detach First, Then iLet Infusion Set	Total
Hispanic or Latino	0	0	—	0	0	0
Not Hispanic or Latino	6	6	—	3	4	19
Unknown or Not Reported	0	0	—	1	0	1

Race (NIH/OMB)
Race (NIH/OMB)(Participants)	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set First, Then Contact Detach	Contact Detach First, Then iLet Infusion Set	Total
American Indian or Alaska Native	0	0	—	0	0	0
Asian	0	0	—	0	0	0
Native Hawaiian or Other Pacific Islander	0	0	—	0	0	0
Black or African American	0	0	—	0	0	0
White	6	6	—	4	4	20
More than one race	0	0	—	0	0	0
Unknown or Not Reported	0	0	—	0	0	0

Region of Enrollment
Region of Enrollment(participants)	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set First, Then Contact Detach	Contact Detach First, Then iLet Infusion Set	Total
United States	6	6	—	4	4	20

Hemoglobin A1c
Hemoglobin A1c(percent)	iPhone Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Lilly Glucagon	iLet Bionic Pancreas - Xerisol Glucagon	iLet Infusion Set First, Then Contact Detach	Contact Detach First, Then iLet Infusion Set	Total
Mean	8.3 ± 0.7	7.6 ± 1.8	—	6.9 ± 1.2	8.1 ± 1.8	7.8 ± 1.2

Study locations

1 site

MGH Diabetes Research Center
Boston, Massachusetts 02114, United States

References and documents

Study documents

Protocol and statistical analysis plan · Oct 3, 2017

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Yes — De-identified IPD will be published as online supplemental material to the main paper describing the results, as we have done for all of our previous bionic pancreas studies.

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Nov 18, 2019, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT02701257
Lead sponsor: Massachusetts General Hospital
Collaborators: Boston University
Responsible party: Steven J. Russell, MD, PhD (Assistant Professor of Medicine, Massachusetts General Hospital) — Principal investigator
First posted: Mar 8, 2016
Start date: Mar 2016
Primary completion: May 2018
Completion: May 2018
Results posted: Nov 18, 2019
Last update: Nov 18, 2019

Study contacts

Steven J Russell, MD, PhD

principal investigator · Massachusetts General Hospital

Oversight

Data monitoring committee: Yes
FDA-regulated device: Yes

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is terminated, as verified in Nov 2019. You cannot join it, but the record below documents what was studied.

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Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

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The iLet Introduction Study: A Feasibility Study of the iLet, a Fully Integrated Bihormonal Bionic Pancreas

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