Watch video of UVA researcher Stacey Anderson, M.D., talking about the DiAs AP system.
The 2015 ADA conference in Boston, MA highlighted the impressive progress that has been made in developing AP technology in less than a decade, and provided a global view of near-term technology, next steps and unanswered challenges on the AP front. Precursor systems are already on the market, and as several JDRF-supported studies demonstrated, hybrid closed-loop systems that offer automated insulin delivery with only a need for mealtime bolusing are moving towards commercial development and applications for Food and Drug Administration (FDA) clearance.
JDRF-supported researcher Boris Kovatchev, Ph.D., and his team at the University of Virginia (UVA) are among the researchers pushing towards commercialization of hybrid systems. The group presented findings from their multicenter, international trial of long-term, around-the-clock use of their Diabetes Assistant (DiAs) AP algorithm. Results from phase II of the trial showed that the DiAs system—which currently runs on an Android phone platform and connects wirelessly to an Accu-Check insulin pump and Dexcom G4 continuous glucose monitor (CGM) sensor—was able to maintain the 15 volunteers’ blood-glucose levels between the target range of 70 to 180 mg/dl throughout the day and night. It was also able to bring their levels to 120 mg/dl at wake-up time. The outcomes support conducting a larger international trial to confirm the system’s safety and efficacy, and move it towards commercial development. Dr. Kovatchev announced during a jointly hosted JDRF and National Institutes of Health meeting that his group has, in fact, formed a company called TypeZero for that purpose.
As another session made clear, designing these systems for pediatric use is also a critically important aim. At the AP Roadmap Update Symposium presented by the ADA and JDRF, Aaron Kowalski, Ph.D., JDRF chief mission office and vice president, Research, spoke of the need for more pediatric studies in the developmental stages of this new technology. “Fewer children than adults achieve Hba1c targets,” he said, noting that young kids and teens could benefit most from having a therapeutic system that provides tighter control of blood-sugar levels.
Stayce Beck, Ph.D., chief of the FDA’s Diabetes Diagnostic Devices Group, pushed for more pediatric trials and noted that the agency has no mandate that AP systems first be approved for adult use. “Pediatric studies should be done alongside adults’ to determine if algorithms need to be tweaked and the user interfaces changed for younger populations,” she said.
JDRF-supported researcher Roman Hovorka, Ph.D., and his team at Cambridge University are already attempting to determine the safety and efficacy of their hybrid AP system in diverse populations. To date, they have conducted six free-living home studies in a variety of groups, including children and pregnant women. In a study presented, Hovorka’s team detailed findings from a two-week, home-use trial that compared blood-glucose levels for 12 volunteers between the ages of 10 and 18 who spent one week each on the hybrid AP system and a sensor-augmented pump. Researchers found that the trial participants stayed within target range (70 to 180 mg/dl) 72 percent of the time when using the AP system compared to 53 percent when using the sensor-augmented pump. The group is planning a yearlong study of their AP system in 6- to 18-year-olds in order to gauge safety, efficacy and usage behavior in young people.
And in a look toward next-generation AP systems, Ahmad Haidar, Ph.D., at the Montreal Institute of Clinical Research performed a head-to-head comparison of how a dual-hormone AP system (DAP) that provided boluses of glucagon and a single-hormone AP system (SAP) that only delivers insulin faired during exercise. Twelve women between the ages of 23 and 51 performed two types of exercise—moderate and interval—using the SAP and DAP systems during different sessions. The DAP system kept the participants in target blood-sugar range more than 90 percent of the time during both forms of exercise, but less frequently with SAP, which achieved target ranges 75 percent of the time during interval and 70 percent during moderate workouts.