Outpatient Studies to Test Viability of Bionic Pancreas
By Mark Dwortzan
Components of the bihormonal bionic endocrine pancreas. The system consists of two infusion pumps and a wireless mobile device, which contains the continuous glucose monitor (CGM) and a mobile phone (Apple iPhone 4S) connected through a custom hardware interface and contained together in a custom enclosure. The sensor transmitter worn by the subject wirelessly communicates with the CGM in the mobile device. The algorithm, which runs within an app on the phone, receives the CGM signal every five minutes through the hardware interface and wirelessly commands insulin and glucagon doses to the two infusion pumps.
When Associate Professor Edward R. Damiano’s (BME) 11-month-old son, David, developed type 1 diabetes in 2000, he started checking the boy’s blood sugar with finger stick measurements 15 times a day, and dosed insulin accordingly with an insulin pump. Adopting new technology in 2008, Damiano equipped his son with a continuous glucose monitor, which still required constant attention to blood sugars and insulin dosing. In 2017, when David attends college, he’ll be on his own, and that’s why for the past 10 years, Damiano has been single-mindedly developing what nearly two million Americans with type 1 diabetes have long sought—an automated, “closed-loop” system that regulates blood glucose with minimal human intervention.
Now, after extensive testing of his software-controlled system on diabetic pigs and in three successful, 24-48-hour, in-hospital feasibility studies of adults and adolescents over the past four-and-a-half years, the Food and Drug Administration has given Damiano—along with Senior Research Associate Firas H. El-Khatib (BME) and Massachusetts General Hospital endocrinologist Dr. Steven J. Russell—the green light to carry out the first of three longer-duration “transitional” outpatient studies over the next 18 months.
Whereas subjects in the feasibility studies were largely immobilized, hooked to IV monitors and Damiano’s laptop-driven system under continuous nursing oversight for up to two days in a hospital, the subjects participating in the transitional studies will move about in more realistic settings while wearing their new iPhone-driven system, with progressively less nursing supervision.
All three transitional studies will test the researchers’ current system, which consists of an app containing the system’s control software that runs on an iPhone, a continuous glucose monitor that’s wirelessly linked to the iPhone, a sensor/transmitter inserted under the skin that streams glucose data to the monitor, and two hormone infusion pumps (one to deliver insulin to lower blood glucose (BG), the other to deliver glucagon to raise it). Based on glucose levels obtained every five minutes, the app determines and dispatches the proper dose of insulin or glucagon to maintain ideal blood sugar levels. Because the system emulates the endocrine pancreas, which continually secretes these two hormones to regulate BG, Damiano calls it a bionic pancreas.
“Our bionic pancreas provides a fully-autonomous system acting over the entire glycemic range, and is totally reactive to blood glucose levels.” said Damiano. “The upcoming transitional studies will still involve close clinical observation of subjects using the device, but will take place in settings where they can be busy doing things other than just thinking about their diabetes.”
Set to start in early February and conclude in June, the first transitional study, the Beacon-Hill Study, will test the system’s performance for five continuous days in 20 adults with type 1 diabetes. Between 7 a.m. and 11 p.m., the subjects will have access to a three-square-mile geographical area near Massachusetts General Hospital (MGH), accompanied by nurses who check their BG levels every two hours via finger stick to ensure the system is working properly. Overnight they’ll sleep in a hotel near MGH and be hooked to an IV that will enable nurses to monitor BG every 30 minutes without disturbing the subjects’ sleep. To compare average glucose levels with and without the bionic pancreas, each subject will also spend an additional five days under their own care at home without the device, but will wear a continuous glucose monitor to record glucose readings..
The second out-patient study, the Summer-Camp Study at Camp Joslin and the Clara Barton Camp in central Massachusetts, will be conducted in July and August, and will test the system for six days in 16 boys and 16 girls with type 1 diabetes. Each subject will undergo six days with the bionic pancreas and six days without, for comparison, all within the camp environment. The third study, the Hospital-Staff Study, slated for the first half of 2014, will test the system in 50–60 adult subjects with type 1 diabetes who also happen to be employees of MGH and several other medical centers. They’ll spend two weeks wearing the device at home and at work, and two additional weeks without it for comparison.
Throughout the 18 months of transitional studies, Damiano and El-Khatib will collaborate with their industrial partners to integrate their technology into a new medical device where the control software will reside on a single, dual-chamber insulin/glucagon pump, rather than on a consumer device such as a smartphone. If all goes well, they will then begin multi-center “pivotal” trials in 2015, testing this final version of their device for six months in hundreds of people with type 1 diabetes—half wearing the device, half continuing their usual care without it. The trials will test the device exactly as it will be used in order to gain FDA approval before it can be released as a commercial product.
“If we can achieve these ambitious milestones, we can have the final device reviewed by the FDA in 2016 and ready for release in 2017,” said Damiano.
Past and current support for this research has been provided by the National Institutes of Health, the Juvenile Diabetes Research Foundation, the Leona M. and Harry B. Helmsley Charitable Trust, the Frederick Banting Foundation, the Wallace H. Coulter Foundation, the Charlton Fund for Innovative Research in Diabetes, the National Center for Research Resources and private donations.
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