Press release

The iLet Bionic Pancreas Increased Time in Range for Adults with Type 1 Diabetes

June 8, 2019 | San Francisco, California

Study presented at ADA’s Scientific Sessions compared insulin-only mode of iLet to usual care

The iLet bionic pancreas (BP)¹ significantly increased the percentage of time adults with type 1 diabetes (T1D) had glucose levels between 70–180 mg/dl, when compared to usual care (UC) therapy of either multiple daily insulin injections (MDI) or continuous subcutaneous insulin infusion (CSII), according to the study, “First Human Study Testing the iLet, a Purpose-Built Bionic Pancreas Platform,” presented today at the American Diabetes Association’s® (ADA’s) 79th Scientific Sessions® at the Moscone Convention Center in San Francisco.

The iLet is a closed-loop, fully integrated BP platform. For the purposes of this study, its insulin-only mode was tested with data from the Dexcom G5 continuous glucose monitoring (CGM) system or the Senseonics Eversense CGM device. During the study, the iLet received a glucose signal from the CGM sensor, ran the insulin-dosing algorithm, and integrated an independently actuated pumping mechanism. The iLet required the user’s weight for initialization, and then autonomously and continuously adapted based upon the range of insulin requirements of the user.

This randomized, cross-over, outpatient study of 34 adults with type 1 diabetes compared the insulin-only mode of the iLet to UC for seven days each. The study included 12 participants who used MDI and 22 patients who used CSII for their UC. The cohort had very good glucose control at baseline, with an average screening A1c of 7.5 ± 1.1%. The 17 participants enrolled at Massachusetts General Hospital used the Senseonics Eversense while the 17 individuals at Stanford used the Dexcom G5 as the input CGM signal for the iLet. The iLet used the same short-acting insulin that the subjects used in their UC (Humalog or Novolog). All subjects (both pump and MDI users) initiated therapy on the iLet in the same way—by entering their body weight. This was the first study of a fully automated insulin delivery system for people on MDI therapy, with no run-in or training period needed for the device, as well as the first study to test the iLet in a home-use setting.

The results showed that there was no statistically significant difference between the iLet and UC for mean CGM glucose (155±12 vs. 162±26 mg/dl). Percentage of time spent in hypoglycemia (<54 mg/dl) was not different between the iLet and UC (0.7±0.6% vs. 0.7±0.8%), and similar for time spent <70 mg/dl (2.8±1.8% vs. 3.2±2.5%). However, the iLet significantly increased the percentage of time spent in the range of 70–180 mg/dl compared to UC (70.1% vs. 61.5%). During the overnight period there was a lower mean CGM glucose in the iLet arm compared to UC (148±18 mg/dl vs. 163±36 mg/dl), but no difference in hypoglycemia. There was no difference in mean CGM glucose in participants using the Dexcom G5 CGM versus the Senseonics Eversense CGM for input to the iLet. Time spent in hypoglycemia (time < 54 mg/dl) when on the iLet was lower for Dexcom G5 CGM users (0.4 ± 0.5%) than Senseonics Eversense CGM users (0.9 ± 0.6%), however, it is unclear whether this represents an actual difference in hypoglycemia or a difference in the detection of hypoglycemia between the two sensors. The mean insulin total daily dose was not significantly different between the iLet and UC groups (44±20 vs. 42±20 u/day). These results suggest that the iLet, using either the Senseonics Eversense CGM or Dexcom G5 CGM for input, may provide safe and effective glycemic control for adults with T1D using insulin pumps or MDI therapy.

“It was encouraging to see that MDI users achieved good glucose control with the iLet in the home setting despite their lack of prior experience with an insulin pump. The dosing algorithms in the bionic pancreas automatically adapted to the patient and their changing insulin requirements, no training period was needed for either the pump or MDI subjects, and their weight was the only data point needed to initiate the iLet,” said lead study author Rabab Jafri, MBBS, MD, assistant director of the Diabetes Center, Pediatric Endocrine Unit at Massachusetts General Hospital. “This study showed that the insulin-only iLet can provide safe and effective glucose control for people with type 1 diabetes, and the results have also led to some improvements in the design of the next generation iLet, which will improve usability and safety.”

To speak with Dr. Jafri, please contact the ADA Press Office on-site at the Moscone Convention Center on June 7-11, by phone at 415-978-3606 or by email at

The American Diabetes Association’s 79th Scientific Sessions, the world’s largest scientific meeting focused on diabetes research, prevention and care, will be held June 7-11, 2019, at the Moscone Center in San Francisco, California. Nearly 15,000 leading physicians, scientists, health care professionals and industry representatives from around the world are expected to convene at the Scientific Sessions to unveil cutting-edge research, treatment recommendations and advances toward a cure for diabetes. During the five-day meeting, attendees will receive exclusive access to more than 850 presentations and 2,000 original research presentations, participate in provocative and engaging exchanges with leading diabetes experts, and can earn Continuing Medical Education (CME) or Continuing Education (CE) credits for educational sessions. The program is grouped into eight thematic areas: Acute and Chronic Complications; Behavioral Medicine, Clinical Nutrition, Education and Exercise; Clinical Diabetes/Therapeutics; Epidemiology/Genetics; Immunology/Transplantation; Insulin Action/Molecular Metabolism; Integrated Physiology/Obesity; and Islet Biology/Insulin Secretion. Gretchen Youssef, MS, RDN, CDE, President of Health Care and Education, will deliver her address, “It’s All About Access!,” on Saturday, June 8, and Louis H. Philipson, MD, PhD, FACP, President of Medicine and Science, will deliver his lecture, “Precision Medicine—Addressing the Many Faces of Diabetes,” on Sunday, June 9. Join the Scientific Sessions conversation on social media using #ADA2019.

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[1] A bionic or “artificial” pancreas is an external device or system of devices that mimics the glucose regulating function of a healthy pancreas. Such systems monitor glucose levels and automatically provide insulin, and potentially other blood-glucose stabilizing hormones, to the body. Current research does not intend to imply that this is a replacement for a pancreas.

, About the American Diabetes Association

Every day more than 4,000 people are newly diagnosed with diabetes in America. Nearly 115 million Americans have diabetes or prediabetes and are striving to manage their lives while living with the disease. The American Diabetes Association (ADA) is the nation’s leading voluntary health organization fighting to bend the curve on the diabetes epidemic and help people living with diabetes thrive. For nearly 80 years the ADA has been driving discovery and research to treat, manage and prevent diabetes, while working relentlessly for a cure. We help people with diabetes thrive by fighting for their rights and developing programs, advocacy and education designed to improve their quality of life. Diabetes has brought us together. What we do next will make us Connected for Life. To learn more or to get involved, visit us at or call 1-800-DIABETES (1-800-342-2383). Join the fight with us on Facebook (American Diabetes Association), Twitter (@AmDiabetesAssn) and Instagram (@AmDiabetesAssn).