The iLet bionic pancreas, which automatically monitors blood glucose levels and delivers tailored insulin doses, is small and lightweight enough to be worn on a belt clip. Photo courtesy of Steven Russell and Ed Damiano
Your pancreas is like a little digestive engine, working hard to keep your body fueled and running. Just six inches long, it’s responsible for turning lunch into the energy that gets you through the afternoon and making sure your blood sugars stay balanced.
But in people with type 1 diabetes, the pancreas fails in the second job. The organ—nestled behind the stomach—doesn’t produce enough insulin, a hormone necessary for converting and storing sugars. Without it, those sweet carbs can’t enter cells, leaving sugars stuck in the bloodstream and people with type 1 diabetes feeling thirsty, hungry, and tired. In the long term, diabetes can cause heart disease and damage the eyes, kidneys, feet, and skin. Patients have to constantly monitor their blood sugar levels and inject insulin in an attempt—often not completely successful—to keep them in check.
There’s no cure for type 1 diabetes. But a bionic pancreas, invented by Boston University biomedical engineers, and in the works for almost 20 years, is moving closer to giving the nearly two million Americans with the chronic disease fresh hope. In a study published Thursday in the New England Journal of Medicine, researchers found the wearable automated insulin delivery device, iLet, was better at managing blood glucose levels than existing standard-of-care methods.
The iLet was developed in the lab of Ed Damiano, a BU College of Engineering professor of biomedical engineering. In 2015, he cofounded a public benefit corporation, Beta Bionics, to advance the technology and bring it to market. His coinventor was Firas El-Khatib, previously a senior research scientist at BU and now Beta Bionics’ VP of research and innovation. Both are authors on the latest paper.
In a 13-week clinical trial at 16 sites across the United States, the iLet improved glycated hemoglobin (A1C) levels—a measure of blood glucose control—reducing them on average from 7.9 percent to 7.3 percent. By contrast, A1C levels didn’t, on average, change in the control group, where participants continued with their existing care programs and continuous glucose monitoring. Although the American Diabetes Association suggests people with type 1 diabetes try to keep their A1C levels below 7 percent—noting that higher levels bring an increased risk of complications—only one in five people in the United States with type 1 diabetes meet that target.
“It sounds so modest, you drop the entire cohort on average a half of one percent, but it’s actually pretty meaningful,” says Damiano, founder and executive chair of Beta Bionics. He says regulators and the industry consider it to be a clinically significant reduction. “Every percentage point reduction in A1C has been shown to confer meaningful reductions in long-term health complications for people with type 1. Across a population, that can be huge.”
According to the researchers, those using the bionic pancreas spent, on average, an additional 2.6 hours a day with their glucose levels in the target range of 70 to 180 milligrams per deciliter. The trial included 326 adults and children, aged from 6 to 79, all with type 1 diabetes; 219 participants were randomly assigned to the bionic pancreas, the rest to standard care. The researchers found an average reduction in A1C in both the adult and child iLet cohorts.
For Damiano, each step forward with the iLet is about more than professional progress—it’s personal. He first began work on the bionic pancreas back in 2002 as part of a mission to help his then five-year-old son, who developed type 1 diabetes as an infant.
The 15-mm-thick iLet is about the length and width of a credit card. Worn on a belt clip—or even in a bra strap or shoved in a pocket—the device communicates with a separate Bluetooth-enabled monitor to continuously track a subject’s glucose levels. Through a thin tube connected to the body, the iLet automatically delivers a tailored dose of insulin every five minutes, which it calculates based on current and past glucose levels; it can also learn and adapt to changing needs based on the body’s response to past insulin deliveries. By contrast, other methods for managing type 1 diabetes require patients to prick a finger or use a monitor to measure their glucose levels, then administer insulin by injection or with a pump—it’s up to them, with help from their physician, to calculate the correct dose.
“Some systems do have partial automation of insulin dosing,” Damiano says. “However, the bionic pancreas autonomously determines the size of each and every insulin dose.”
For most people with type 1 diabetes, maintaining optimal blood sugar levels is a 24/7 endeavor—Damiano says the disease is relentless.
“You’re basically metering dosing of a very dangerous drug all the time,” Damiano says of many existing approaches. “Insulin is a life-saving hormone, a life-critical hormone, but it’s very, very sensitive. Tiny drops of insulin can confer big changes in glucose, so even the slightest overdose can have grave consequences. And consistently underdosing, in response to fear of acute hypoglycemia, low blood sugar, can have long-term complications.”
When the researchers broke the trial results down, they found differences across demographic groups. The study showed the iLet had a much greater impact on participants who were non-white, earned less than $100,000, or who didn’t have a bachelor’s degree. Those groups started with higher baseline A1C levels, but experienced greater reductions—of more than 1 percent in some cases.
“The iLet is designed to require hardly anything of you,” says Damiano. “As much as possible, it’s designed to be like a self-driving car—as opposed to holding the wheel and making all the insulin-dosing decisions. That’s a categorically different experience.”
The researchers also published a series of related papers in Diabetes Technology & Therapeutics, including a study that found standard care patients who later switched to the bionic pancreas saw similar benefits to those in the main study.
“Keeping tight control over blood glucose is important in managing diabetes and is the best way to prevent complications like eye, nerve, kidney, and cardiovascular disease down the road,” says Guillermo Arreaza-Rubín, director of the National Institute of Diabetes and Digestive and Kidney Diseases diabetes technology program. “The bionic pancreas technology introduces a new level of ease to the day-to-day management of type 1 diabetes, which may contribute to improved quality of life.”
In 2014, Damiano and colleagues at Massachusetts General Hospital successfully tested an early version of the bionic pancreas in two five-day trials; by 2019, Beta Bionics had secured more than $137 million in funding.
Earlier this year, Beta Bionics submitted the iLet to the US Food and Drug Administration for commercial clearance. Damiano says the latest trial was a pivotal one—“it’s bigger than any other done to test an automated insulin delivery system”—and that the company hopes to get federal clearance to market the bionic pancreas in the United States soon. For now, the device only infuses insulin, but Damiano and his team have also been working on a version that stops sugar levels from getting too low by automatically delivering another hormone: glucagon.
“Even for people who are getting really good glucose control through great effort of their own,” says Damiano, “when they go on the iLet, there’s the possibility they’ll feel a tremendous relief from giving up the control and this constant diligence.”
The clinical trial was primarily funded by a grant to BU from the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health. Funding was also provided by Novo Nordisk and Beta Bionics.
Bionic Pancreas Better for Managing Type 1 Diabetes
Andrew Thurston is originally from England, but has grown to appreciate the serial comma and the Red Sox, while keeping his accent (mostly) and love of West Ham United. He joined BU in 2007, and is the editor of the University’s research news site, The Brink; he was formerly director of alumni publications. Before joining BU, he edited consumer and business magazines, including for corporations, nonprofits, and the UK government. His work has won awards from the Council for Advancement and Support of Education, the In-House Agency Forum, Folio:, and the British Association of Communicators in Business. Andrew has a bachelor’s degree in English and related literature from the University of York. Profile
Boston University moderates comments to facilitate an informed, substantive, civil conversation. Abusive, profane, self-promotional, misleading, incoherent or off-topic comments will be rejected. Moderators are staffed during regular business hours (EST) and can only accept comments written in English. Statistics or facts must include a citation or a link to the citation.
Most people find the glucose sensors to be too inaccurate for insulin dosing. Technically, they are accurate. They accurately measure interstitial glucose, which is not blood glucose.
The dexcom g6 cgm CAN, per the FDA, be used for insulin dosing decisions. I think CGM is the most liberating and life changing tool on the market for diabetes management. I’m not sure who your “most people” are ( I only hear other people with diabetes singing the song of how amazing dexcom is), but this diabetic has had A1cs between 5.6 & 6.4 for almost 5 years thanks to CGM.
Will need to look into this, but I want to know if I still have to enter carb values with this pump system? Is it really totally automated? Wild!
My son Richard developed Diabetes Type 1 during his A level exams , about 18 years of age. He has found it very difficult to accept the condition, although realises his need to use Insulin. He monitor’s with a finger prick reading and injects insulin, although a lot of the time his readings are high. After 3 section admissions into a hospital ward, he is making some progress with his life. Can you please help us with the above device, as the care he receives is hopeless.
With sincere thanks, Frances Royston. ( Richards mother)
(Richard is no 30 year’s old)
It will release the pain and trouble of everyone and help the people.
I am one of them and will be happy to get one please
Your email address will not be published. Required fields are marked *
Boston University’s Alumni Magazine
News, Opinion, Community
Pioneering Research from Boston University