Bionic Pancreas Improves A1C and Time in Range
By Andrew Briskin
A study recently published in the New England Journal of Medicine shows that a bionic pancreas, or a closed-loop automated insulin delivery system, kept blood glucose levels in range better than standard insulin delivery methods for type 1 diabetes.
In recent years, significant advancements in continuous glucose monitoring (CGM) and other diabetes technology have led to the development of automated insulin delivery (AID) systems, smart insulin pens, and new pumps. While these systems have made insulin dosing easier for many with type 1, the tasks of adjusting insulin dosing at every meal, counting carbs, and keeping track of a personalized insulin regimen can still be a challenge.
The iLet Bionic Pancreas is a new AID system currently under FDA review that hopes to eliminate the need for these tasks. In a study published in the New England Journal of Medicine (NEJM) on Sept. 29, researchers compared existing insulin delivery methods to the iLet Bionic Pancreas. iLet consists of a tubed insulin pump paired a Dexcom G6 CGM. But unlike other AID systems, iLet eliminates the need to carb count or manually dose mealtime insulin, set basal rates, or administer and determine correction doses to treat high blood sugar.
For the initial setup, users enter only their body weight. After that, when it’s time to eat a meal, the user can enter two inputs – the type of meal (breakfast, lunch, or dinner) and size of the meal (usual for me, less, or more). From here, iLet makes all dosing decisions and delivers insulin automatically, without the need for the user to count carbs. And while entering the type and size of the meal is recommended, this step is not required; iLet will still adjust insulin automatically based on CGM readings.
“This is a very significant advancement in closed loop technologies,” said Dr. Nelly Mauras, pediatric endocrinologist and Vice Chair of Pediatrics for Research at Nemours Children’s Health in Jacksonville, Florida, and one of the sites' principal investigators of the NEJM study. “The uniqueness of this particular device recorded in our paper is that the only input necessary for its operation is the patient’s body weight. There is no need to put basal insulin doses, insulin to carbohydrate ratios, high glucose boluses. None of that is required.”
The 13-week multi-center study included 326 participants with type 1 diabetes between ages 6 and 79. People were split into two groups; 219 participants transitioned to the bionic pancreas, while 107 continued using their pre-study insulin delivery method. Researchers measured the differences in A1C from beginning to end of the study, improvements in time in range, and hypoglycemia events.
In the bionic pancreas group, participants’ A1C decreased, on average, from 7.9% to 7.3% over the course of the study. Also, average time in range improved by 11% on average, which equals roughly 2 hours and 40 minutes more spent in a healthy glucose range each day. In the group that continued with their pre-study insulin delivery method, there was no improvement in A1C or time in range. Also, there were no instances of diabetic ketoacidosis (DKA) and no difference in the rates of hypoglycemia between groups.
“The most significant takeaway from the trial data, as I see it, is that a bionic pancreas was able to achieve a clinically relevant reduction in A1C (0.5%) without increasing sensor-measured hypoglycemia, in comparison to the standard of care insulin delivery methods with CGM,” said Dr. Edward Damiano, professor of biomedical engineering at Boston University and co-founder of Beta Bionics, the company developing the iLet Bionic Pancreas.
Perhaps more importantly, Damiano added, is that users on the bionic pancreas were able to achieve these results:
Without carb counting or setting and adjusting carb-to-insulin ratios, basal rates, or insulin sensitivity factors
Without the need for experience using a pump or CGM
Without any run-in period for device training before starting the device
Both Mauras and Damiano also praised the consistency of the improvements from the bionic pancreas, despite the diversity of participants in the trial. The participants included children as young as six, as well as older adults. Additionally, there were people entering the trial with a baseline A1C up to 14.9%, using all types of insulin delivery ranging from multiple daily injections (MDI) to other insulin pumps and AID systems.
“We intentionally set up this study to include as broad a spectrum of ages as possible in order to increase the generalizability of the results,” said Mauras. “At Nemours Children’s Health, Jacksonville, we recruited young people between the ages of 6 to less than 21 years old. Of course, the families have to be involved with the young ones directly in order for any insulin program to work. The biggest difference of the bionic pancreas is the fact that providers, users, or the parents of the users do not have to make any decisions [besides the suggested meal input described above] to use the device.”
Mauras added that the device was generally simple to set up. “I can attest to the fact, even patients transitioning from multiple daily injections (MDI) were able to make that transition with standard training with relative ease.”
On the diversity of the trial, Damiano said that the greatest improvements on average glucose occurred in those with the highest A1c levels at baseline, on MDI therapy, with household incomes less than $100k per year, with less than a bachelor’s degree, and those who were non-white, non-Hispanic.
“Given that the insulin-only iLet performed so well in the pivotal trial, and did so in a more diverse cohort than has been studied in any other AID trial,” he said, “I think the iLet offers the possibility of being complementary to other AID systems, which have also been shown to perform well, albeit in trials with more restrictions and less diverse study cohorts.”
This trial data represents a critical step towards the availability of iLet. iLet will continue to undergo a priority review following a “breakthrough device” designation from the FDA, given to the device in December 2019. This designation is given to devices that could potentially provide more effective treatment for life-threatening conditions, such as diabetes.
“This bionic pancreas greatly simplifies the user-device interaction and that, to me, is a game changer,” Mauras said. “However, this device was used for only up to six months, hence more data are needed to better assess the long-term efficacy and safety of this long-term approach. [The data], however, offers hope.”
For more about the iLet Bionic Pancreas and past clinical trial results, read: