Utility and Safety of Backup Insulin Regimens Generated by the Bionic Pancreas: A Randomized Study

The bionic pancreas (BP) is initialized with body weight only and doses insulin autonomously without carbohydrate counting, instead using qualitative meal announcements. In case of device malfunction, the BP generates and continuously updates backup insulin doses for injection or pump users, including long-acting insulin dose, a four-period basal insulin profile, short-acting meal doses, and a glucose correction factor. Following a 13-week trial in type 1 diabetes, participants using the BP (6-83 years) completed 2-4 days, in which they were randomly assigned to their prestudy insulin regimen (N = 147) or to follow BP-provided guidance (N = 148). Glycemic outcomes with BP guidance were similar to those reinstituting their prestudy insulin regimen, with both groups having higher mean glucose and lower time-in-range than while using the BP during the 13-week trial. In conclusion, a backup insulin regimen automatically generated by the BP can be safely implemented if need arises to discontinue use of the BP. Clinical Trial Registry: clinicaltrials.gov; NCT04200313.

The Insulin-Only Bionic Pancreas Pivotal Trial Extension Study: A Multi-Center Single-Arm Evaluation of the Insulin-Only Configuration of the Bionic Pancreas in Adults and Youth with Type 1 Diabetes

Objective: To evaluate a transition from standard-of-care (SC) management of type 1 diabetes (any insulin delivery method including hybrid closed-loop systems plus real-time continuous glucose monitoring [CGM]) to use of the insulin-only configuration of the iLet® bionic pancreas (BP) in 90 adults and children (age 6-71 years). Research Design and Methods: After the SC group completed the randomized controlled trial (RCT) portion of the Insulin-Only BP Pivotal Trial, 90 of the 107 participants participated in a 13-week study using the BP. The key outcomes were change from baseline in HbA1c and CGM metrics after 13 weeks on the BP. Results: Using the BP, mean HbA1c decreased from 7.7% ± 1.0% (61 ± 10.9 mmol/mol) at baseline to 7.1% ± 0.6% (54 ± 6.6 mmol/mol) at 13 weeks (mean change -0.55% ± 0.72% [-6 ± 7.9 mmol/mol], P < 0.001), time in range 70-180 mg/dL increased by 12.0% ± 12.5% (from 53% ± 17% to 65% ± 9%, P < 0.001), and mean glucose decreased by -18 ± 23 mg/dL (from 182 ± 32 to 164 ± 15 mg/dL, P < 0.001). The higher the baseline HbA1c level, the greater the change in HbA1c. Results were similar in the adult (N = 42) and pediatric (N = 48) cohorts. Time <70 mg/dL decreased from baseline over the 13 weeks by -0.50% ± 1.86% (P = 0.02), and time <54 mg/dL was similar (change from baseline -0.08% ± 0.59%, P = 0.24). Two severe hypoglycemia events (in same participant) and one diabetic ketoacidosis event occurred. Conclusions: Glycemic control improved after adult and pediatric participants in the SC arm in the Insulin-Only BP Pivotal Trial transitioned to use of the BP. Improvement using the BP was of similar magnitude to that observed during the RCT. ClinicalTrials.gov number, NCT04200313.

A Multicenter Randomized Trial Evaluating Fast-Acting Insulin Aspart in the Bionic Pancreas in Adults with Type 1 Diabetes

Objective: To evaluate the insulin-only configuration of the iLet® bionic pancreas (BP) using fast-acting insulin aspart (Fiasp®) in adults with type 1 diabetes (T1D). Research Design and Methods: In this multicenter, randomized trial, 275 adults with T1D (18-83 years old, baseline HbA1c 5.3%-14.9%) were randomly assigned 2:2:1 to use the BP with fast-acting insulin aspart (BP-F group, N = 114), BP with aspart or lispro (BP-A/L group, N = 107), or a control group using their standard-care insulin delivery (SC group, N = 54) plus real-time continuous glucose monitoring (CGM). The primary outcome was HbA1c at 13 weeks. The BP-F versus SC comparison was considered primary and BP-F versus BP-A/L secondary. Results: Mean ± standard deviation (SD) HbA1c decreased from 7.8% ± 1.2% at baseline to 7.1% ± 0.6% at 13 weeks with BP-F versus 7.6% ± 1.2% to 7.5% ± 0.9% with SC (adjusted difference = -0.5%, 95% CI -0.7 to -0.3, P < 0.001). CGM-measured percent time <54 mg/dL over 13 weeks with BP-F was noninferior to SC (adjusted difference = 0.00%, 95% CI -0.07 to 0.05, P < 0.001 for noninferiority based on a prespecified noninferiority limit of 1%). Over 13 weeks, mean time in range 70-180 mg/dL (TIR) increased by 14% (3.4 h/day) and mean CGM glucose was reduced by 18 mg/dL with BP-F compared with SC (P < 0.001). Analyses of time >180 mg/dL, time >250 mg/dL, and the SD of CGM glucose all favored BP-F compared with SC (P < 0.001). Differences between BP-F and BP-A/L were minimal, with no difference in HbA1c at 13 weeks (adjusted difference = -0.0%, 95% CI -0.2 to 0.1, P = 0.67) or mean glucose (adjusted difference = -2.0 mg/dL, 95% CI -4.3 to 0.4, P = 0.10). Mean TIR was 2% greater with BP-F than BP-A/L (95% CI 1 to 4, P = 0.005), but the percentages of participants improving TIR by ≥5% were not significantly different (P = 0.49) and there were no significant differences comparing BP-F versus BP-A/L across nine patient-reported outcome surveys. The rate of severe hypoglycemia events did not differ among the three groups. Conclusions: In adults with T1D, HbA1c was improved with the BP using fast-acting insulin aspart compared with standard care without increasing CGM-measured hypoglycemia. However, the effect was no better than the reduction observed with the BP using aspart or lispro. Clinical Trial Registry: clinicaltrials.gov; NCT04200313.

A Multicenter Randomized Trial Evaluating the Insulin-Only Configuration of the Bionic Pancreas in Adults with Type 1 Diabetes

Objective: To evaluate the insulin-only configuration of the iLet® bionic pancreas (BP) using insulin aspart or insulin lispro in adults with type 1 diabetes (T1D). Methods: In this multicenter, randomized, controlled trial, 161 adults with T1D (18-79 years old, baseline HbA1c 5.5%-13.1%, 32% using multiple daily injections, 27% using a pump without automation, 5% using a pump with predictive low glucose suspend, and 36% using a hybrid closed loop system before the study) were randomly assigned 2:1 to use the BP (N = 107) with insulin aspart or insulin lispro (BP group) or a standard-of-care (SC) control group (N = 54) using their usual insulin delivery plus continuous glucose monitoring (CGM). The primary outcome was HbA1c at 13 weeks. Results: Mean HbA1c decreased from 7.6% ± 1.2% at baseline to 7.1% ± 0.6% at 13 weeks with BP versus 7.6% ± 1.2% to 7.5% ± 0.9% with SC (adjusted difference = -0.5%, 95% confidence interval -0.6% to -0.3%, P < 0.001). Over 13 weeks, mean time in range 70-180 mg/dL (TIR) increased by 11% (2.6 h/d) and mean CGM glucose was reduced by 16 mg/dL with BP compared with SC (P < 0.001). Improvement in these metrics was seen during the first day of BP use and by the end of the first week reached levels that remained relatively stable through 13 weeks. Analyses of time >180 mg/dL, time >250 mg/dL, and standard deviation of CGM glucose all favored the BP group (P < 0.001). The CGM-measured hypoglycemia was low at baseline (median time <54 mg/dL of 0.21% [3 min/d] for the BP group and 0.11% [1.6 min/d] for the SC group) and not significantly different between groups over the 13 weeks (P = 0.51 for time <70 mg/dL and 0.33 for time <54 mg/dL). There were 7 (6.5% of 107 participants) severe hypoglycemic events in the BP group and 2 events in the SC group (1.9% of 54 participants, P = 0.40). Conclusions: In adults with T1D, use of the BP with insulin aspart or insulin lispro improved HbA1c, TIR, and hyperglycemic metrics without increasing CGM-measured hypoglycemia compared with standard of care. Clinical Trial Registry: clinicaltrials.gov; NCT04200313.

WITHDRAWN: Positive Impact of the Bionic Pancreas on Diabetes Control in Youth 6-17 Years Old with Type 1 Diabetes: A Multicenter Randomized Trial

The publisher of Diabetes Technologies & Therapeutics officially withdraws the Just Accepted version of the article entitled, "Positive Impact of the Bionic Pancreas on Diabetes Control in Youth 6-17 Years Old with Type 1 Diabetes: A Multicenter Randomized Trial," by Laurel H Messer, et al. (epub 28 Jun 2022; DOI: 10.1089/dia.2022.0201) due to its erroneous release before being finalized. The correct version will be republished in due course. The publisher extends its sincerest apologies to the authors of the article and to the journal's readership for this regrettable mishap.

Improvements in Glycemic Control Achieved by Altering the tmax Setting in the iLet® Bionic Pancreas When Using Fast-Acting Insulin Aspart: A Randomized Trial

INTRODUCTION

We investigated the safety of, and glucose control by, the insulin-only configuration of the iLet^® bionic pancreas delivering fast-acting insulin aspart (faster aspart), using the same insulin-dosing algorithm but different time to maximal serum drug concentration (t_max) settings, in adults with type 1 diabetes.

METHODS

We performed a single-center, single-blinded, crossover (two 7-day treatment periods) escalation trial over three sequential cohorts. Participants from each cohort were randomized to a default t_max setting (t₆₅ [t_max = 65 min]) followed by a non-default t_max setting (t₅₀ [t_max = 50 min; cohort 1], t₄₀ [t_max = 40 min; cohort 2], t₃₀ [t_max = 30 min; cohort 3]), or vice versa, all with faster aspart. Each cohort randomized eight new participants if escalation-stopping criteria were not met in the previous cohort.

RESULTS

Overall, 24 participants were randomized into three cohorts. Two participants discontinued treatment, one due to reported 'low blood glucose' during the first treatment period of cohort 3 (t₃₀). Mean time in low sensor glucose (< 54 mg/dl, primary endpoint) was < 1.0% for all t_max settings. Mean sensor glucose in cohorts 1 and 2 was significantly lower at non-default versus default t_max settings, with comparable insulin dosing. The mean time sensor glucose was in range (70-180 mg/dl) was > 70% for all cohorts, except the default t_max setting in cohort 1. No severe hypoglycemic episodes were reported. Furthermore, there were no clinically significant differences in adverse events between the groups.

CONCLUSION

There were no safety concerns with faster aspart in the iLet at non-default t_max settings. Improvements were observed in mean sensor glucose without increases in low sensor glucose at non-default t_max settings.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03816761.

Comparative Accuracy of 17 Point-of-Care Glucose Meters

BACKGROUND

The accuracy of point-of-care blood glucose (BG) meters is important for the detection of dysglycemia, calculation of insulin doses, and the calibration of continuous glucose monitors. The objective of this study was to compare the accuracy of commercially available glucose meters in a challenging laboratory study using samples with a wide range of reference BG and hemoglobin values.

METHODS

Fresh, discarded blood samples from a hospital STAT laboratory were either used without modification, spiked with a glucose solution, or incubated at 37°C to produce 347 samples with an even distribution across reference BG levels from 20 to 440 mg/dl and hemoglobin values from 9 to 16 g/dl. We measured the BG of each sample with 17 different commercially available glucose meters and the reference method (YSI 2300) at the same time. We determined the mean absolute relative difference (MARD) for each glucose meter, overall and stratified by reference BG and by hemoglobin level.

RESULTS

The accuracy of different meters widely, exhibiting a range of MARDs from 5.6% to 20.8%. Accuracy was lower in the hypoglycemic range, but was not consistently lower in samples with anemic blood hemoglobin levels.

CONCLUSIONS

The accuracy of commercially available glucose meters varies widely. Although the sample mix in this study was much more challenging than those that would be collected under most use conditions, some meters were robust to these challenges and exhibited high accuracy in this setting. These data on relative accuracy and robustness to challenging samples may be useful in informing the choice of a glucose meter.

Home use of a bihormonal bionic pancreas versus insulin pump therapy in adults with type 1 diabetes: a multicentre randomised crossover trial

BACKGROUND

The safety and effectiveness of a continuous, day-and-night automated glycaemic control system using insulin and glucagon has not been shown in a free-living, home-use setting. We aimed to assess whether bihormonal bionic pancreas initialised only with body mass can safely reduce mean glycaemia and hypoglycaemia in adults with type 1 diabetes who were living at home and participating in their normal daily routines without restrictions on diet or physical activity.

METHODS

We did a random-order crossover study in volunteers at least 18 years old who had type 1 diabetes and lived within a 30 min drive of four sites in the USA. Participants were randomly assigned (1:1) in blocks of two using sequentially numbered sealed envelopes to glycaemic regulation with a bihormonal bionic pancreas or usual care (conventional or sensor-augmented insulin pump therapy) first, followed by the opposite intervention. Both study periods were 11 days in length, during which time participants continued all normal activities, including athletics and driving. The bionic pancreas was initialised with only the participant's body mass. Autonomously adaptive dosing algorithms used data from a continuous glucose monitor to control subcutaneous delivery of insulin and glucagon. The coprimary outcomes were the mean glucose concentration and time with continuous glucose monitoring (CGM) glucose concentration less than 3·3 mmol/L, analysed over days 2-11 in participants who completed both periods of the study. This trial is registered with ClinicalTrials.gov, number NCT02092220.

FINDINGS

We randomly assigned 43 participants between May 6, 2014, and July 3, 2015, 39 of whom completed the study: 20 who were assigned to bionic pancreas first and 19 who were assigned to the comparator first. The mean CGM glucose concentration was 7·8 mmol/L (SD 0·6) in the bionic pancreas period versus 9·0 mmol/L (1·6) in the comparator period (difference 1·1 mmol/L, 95% CI 0·7-1·6; p<0·0001), and the mean time with CGM glucose concentration less than 3·3 mmol/L was 0·6% (0·6) in the bionic pancreas period versus 1·9% (1·7) in the comparator period (difference 1·3%, 95% CI 0·8-1·8; p<0·0001). The mean nausea score on the Visual Analogue Scale (score 0-10) was greater during the bionic pancreas period (0·52 [SD 0·83]) than in the comparator period (0·05 [0·17]; difference 0·47, 95% CI 0·21-0·73; p=0·0024). Body mass and laboratory parameters did not differ between periods. There were no serious or unexpected adverse events in the bionic pancreas period of the study.

INTERPRETATION

Relative to conventional and sensor-augmented insulin pump therapy, the bihormonal bionic pancreas, initialised only with participant weight, was able to achieve superior glycaemic regulation without the need for carbohydrate counting. Larger and longer studies are needed to establish the long-term benefits and risks of automated glycaemic management with a bihormonal bionic pancreas.

FUNDING

National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health, and National Center for Advancing Translational Sciences.

Day and night glycaemic control with a bionic pancreas versus conventional insulin pump therapy in preadolescent children with type 1 diabetes: a randomised crossover trial

BACKGROUND

The safety and efficacy of continuous, multiday, automated glycaemic management has not been tested in outpatient studies of preadolescent children with type 1 diabetes. We aimed to compare the safety and efficacy of a bihormonal bionic pancreas versus conventional insulin pump therapy in this population of patients in an outpatient setting.

METHODS

In this randomised, open-label, crossover study, we enrolled preadolescent children (aged 6-11 years) with type 1 diabetes (diagnosed for ≥1 year) who were on insulin pump therapy, from two diabetes camps in the USA. With the use of sealed envelopes, participants were randomly assigned in blocks of two to either 5 days with the bionic pancreas or conventional insulin pump therapy (control) as the first intervention, followed by a 3 day washout period and then 5 days with the other intervention. Study allocation was not masked. The autonomously adaptive algorithm of the bionic pancreas received data from a continuous glucose monitoring (CGM) device to control subcutaneous delivery of insulin and glucagon. Conventional insulin pump therapy was administered by the camp physicians and other clinical staff in accordance with their established protocols; participants also wore a CGM device during the control period. The coprimary outcomes, analysed by intention to treat, were mean CGM-measured glucose concentration and the proportion of time with a CGM-measured glucose concentration below 3·3 mmol/L, on days 2-5. This study is registered with ClinicalTrials.gov, number NCT02105324.

FINDINGS

Between July 20, and Aug 19, 2014, 19 children with a mean age of 9·8 years (SD 1·6) participated in and completed the study. The bionic pancreas period was associated with a lower mean CGM-measured glucose concentration on days 2-5 than was the control period (7·6 mmol/L [SD 0·6] vs 9·3 mmol/L [1·7]; p=0·00037) and a lower proportion of time with a CGM-measured glucose concentration below 3·3 mmol/L on days 2-5 (1·2% [SD 1·1] vs 2·8% [1·2]; p<0·0001). The median number of carbohydrate interventions given per participant for hypoglycaemia on days 1-5 (ie, glucose <3·9 mmol/L) was lower during the bionic pancreas period than during the control period (three [range 0-8] vs five [0-14]; p=0·037). No episodes of severe hypoglycaemia were recorded. Medium-to-large concentrations of ketones (range 0·6-3·6 mmol/dL) were reported on seven occasions in five participants during the control period and on no occasion during the bionic pancreas period (p=0·063).

INTERPRETATION

The improved mean glycaemia and reduced hypoglycaemia with the bionic pancreas relative to insulin pump therapy in preadolescent children with type 1 diabetes in a diabetes camp setting is a promising finding. Studies of a longer duration during which children use the bionic pancreas during their normal routines at home and school should be done to investigate the potential for use of the bionic pancreas in real-world settings.

FUNDING

The Leona M and Harry B Helmsley Charitable Trust and the US National Institute of Diabetes and Digestive and Kidney Diseases.

Outpatient glycemic control with a bionic pancreas in type 1 diabetes

BACKGROUND

The safety and effectiveness of automated glycemic management have not been tested in multiday studies under unrestricted outpatient conditions.

METHODS

In two random-order, crossover studies with similar but distinct designs, we compared glycemic control with a wearable, bihormonal, automated, "bionic" pancreas (bionic-pancreas period) with glycemic control with an insulin pump (control period) for 5 days in 20 adults and 32 adolescents with type 1 diabetes mellitus. The automatically adaptive algorithm of the bionic pancreas received data from a continuous glucose monitor to control subcutaneous delivery of insulin and glucagon.

RESULTS

Among the adults, the mean plasma glucose level over the 5-day bionic-pancreas period was 138 mg per deciliter (7.7 mmol per liter), and the mean percentage of time with a low glucose level (<70 mg per deciliter [3.9 mmol per liter]) was 4.8%. After 1 day of automatic adaptation by the bionic pancreas, the mean (±SD) glucose level on continuous monitoring was lower than the mean level during the control period (133±13 vs. 159±30 mg per deciliter [7.4±0.7 vs. 8.8±1.7 mmol per liter], P<0.001) and the percentage of time with a low glucose reading was lower (4.1% vs. 7.3%, P=0.01). Among the adolescents, the mean plasma glucose level was also lower during the bionic-pancreas period than during the control period (138±18 vs. 157±27 mg per deciliter [7.7±1.0 vs. 8.7±1.5 mmol per liter], P=0.004), but the percentage of time with a low plasma glucose reading was similar during the two periods (6.1% and 7.6%, respectively; P=0.23). The mean frequency of interventions for hypoglycemia among the adolescents was lower during the bionic-pancreas period than during the control period (one per 1.6 days vs. one per 0.8 days, P<0.001).

CONCLUSIONS

As compared with an insulin pump, a wearable, automated, bihormonal, bionic pancreas improved mean glycemic levels, with less frequent hypoglycemic episodes, among both adults and adolescents with type 1 diabetes mellitus. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; ClinicalTrials.gov numbers, NCT01762059 and NCT01833988.).