The Set-Point Study: Evaluating Effects of Changing Glucose Target on Bionic Pancreas Performance

The Set-Point Study: Evaluating Effects of Changing Glucose Target on Bionic Pancreas Performance

The current study is designed to determine the effect on mean glucose, hypoglycemia, glucagon usage, and insulin usage of adjusting upward the glucose target of the bi-hormonal bionic pancreas, and determine whether there is a target at which adequate glycemic control is achieved by an insulin-only bionic pancreas with minimal hypoglycemia.

We have two specific aims:

Aim 1 is to conduct an outpatient study testing multiple configurations of the bionic pancreas in 24 adult subjects with type 1 diabetes in a random cross-over study versus usual care with an insulin pump. These bionic pancreas configurations include the insulin only BP at 145 mg/dl set point, 130 mg/dl set point, 120 mg/dl set point and 110 mg/dl set point and the bihormonal BP at 130 mg/dl set point, 115 mg/dl set point and 110 mg/dl set point. These arms are all compared to usual care.

Aim 2 is to evaluate the incremental utility of glucagon in the context of automated insulin delivery by the bionic pancreas in preventing hypoglycemia during exercise in the fasted state. The 130 mg/dl set points and 110 mg/dl set points also participate in this fasted exercise visit. These two set points are double blinded, so neither the subjects nor the study staff are aware which arm is bihormonal and which arm is insulin only.

Inclusion Criteria:

Type 1 Diabetes Subjects: Age ≥ 18 years and have had clinical type 1 diabetes for at least one year, and managed using an insulin pump for ≥ 6 months Type 2 Diabetes subjects: Age ≥ 18 years and have type 2 diabetes managed with rapid acting insulin in an insulin pump, or multiple daily injections including both long acting and short acting insulin

• 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)
• Live within a 60 minute drive-time radius of the central monitoring location
• Willing to remain within a 120 minute drive-time radius of the central monitoring location throughout the study
• Have someone over 18 years of age who lives with them, has access to where they sleep, is willing to be in the house when the subject is sleeping, and is willing to receive calls from the study staff and check the welfare of the study subject if telemetry shows a technical problem or severe biochemical hypoglycemia without subject response and the subject does not answer their telephone (up to two individuals can share this role, but they must be willing to carefully coordinate with each other and the subject so that one of them is clearly designated as having this responsibility at any given time)
• Willing to wear two infusion sets and one CGM sensor and change sets frequently (at least one new glucagon infusion set daily during bi-hormonal arms, and insulin infusion set every other day throughout the study)
• Have a mobile phone they are willing to keep with them and answer calls from study staff

Exclusion Criteria:

• 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
• Need to go outside of the designated geographic boundaries during the study
• 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 from drinking more than 2 drinks in an hour or more than 4 drinks in a day or use of marijuana during the trial
• Unwilling or unable or to avoid 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)
• Abnormal EKG consistent with coronary artery disease or increased risk of malignant arrhythmia including, but not limited to, evidence of active ischemia, prior myocardial infarction, proximal LAD critical stenosis (Wellen's sign), prolonged QT interval (> 440 ms). Non-specific ST segment and T wave changes are not grounds for exclusion in the absence of symptoms or history of heart disease. A reassuring evaluation by a cardiologist after an abnormal EKG finding may allow participation.
• 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:

oEpisodic or treatment refractory (requiring 4 or more medications to achieve normotension) hypertension oParoxysms of tachycardia, pallor, or headache oPersonal 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
• Unable to completely avoid acetaminophen for duration of study
• 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
• History of eating disorder within the last 2 years, such as anorexia, bulimia, or diabulemia or omission of insulin to manipulate weight
• History of intentional, inappropriate administration of insulin leading to severe hypoglycemia requiring treatment
• Type 1 diabetes subjects: Use of oral (e.g. thiazolidinediones, biguanides, sulfonylureas, glitinides, DPP-4 inhibitors, SGLT-2 inhibitors) anti-diabetic medications
• Type 2 diabetes subjects: Use of oral anti-diabetic medications other than metformin
• Lives in or frequents areas with poor Verizon wireless network coverage (which would prevent remote monitoring)
• Any factors that, in the opinion of the principal investigator would interfere with the safe completion of the study