A version of the artificial pancreas could be available within the next 2 years, according to a review.
The device -- which uses a closed-loop algorithm to monitor blood glucose in type 1 diabetes patients and automatically adjusts insulin levels -- has already undergone several smaller trials in different populations and in different settings, wrote , and , at the University of Cambridge in England.
But those trials have been relatively small and short-term, and several issues must be addressed before the device is up for approval, including speed of action, accuracy of glucose monitors, reliability, and cybersecurity, since the device would need to be protected from hacking. Thabit and Hovorka published their review on Thursday in .
"Significant milestones, with research moving from laboratory to free-living unsupervised home settings, have been achieved in the past decade," wrote the authors. They noted that the challenges to other potential treatments like beta cell transplantation -- transplanting functional islet cells into the pancreas -- and immunological therapies make closed-loop systems a "viable alternative" in the meantime.
The artificial pancreas has attracted a lot of attention in the form of money. Worldwide, funders have provided grants for more than $200 million to study the artificial pancreas on top of the significant resources from pharmaceutical companies And , at Boston University -- one of the earliest and most well-known of the researchers working on closed-loop systems -- founded earlier this year. The company has designed a bi-hormonal bionic pancreas called the iLet that integrates insulin and glucagon delivery systems into a single device.
Damiano has also said that 2018 is a realistic date for a device to reach the market, adding that a large trial is planned for 2017. So far, the device has been studied in the laboratory and in real-world settings like summer camps, hotels, and at home. It has generally outperformed or matched pump therapies in the setting that it has been studied in -- the authors called the totality of the results "encouraging" -- and dual hormone systems minimize the risk of hypoglycemia that can come with tighter glucose control.
But Thabit and Hovorka added that long-term data are still needed on the safety and tolerability of subcutaneously delivering glucagon. And the 2018 date is dependent not only on approval from the FDA but also on whether infrastructure and support is in place for clinicians who are providing care, they said.
Another challenge: "Performance of closed-loop systems is damped by variable and relatively slow absorption of currently available rapid-acting insulin analogues, delaying onset of and prolonging insulin action," wrote the authors, adding that this is a serious concern during exercise and postprandial conditions, because that is when glucose fluctuations can happen.
A few further technological advances could make the device more appealing to users, including better glucose sensing, a smaller glucose sensor, avoidance of the need for calibration, and a longer sensor wear time.
"Further technological advancements should also focus on improvements in insulin delivery to prolong infusion catheter use, reduce silent infusion catheter occlusions and accelerate insulin absorption and action to improve efficacy of closed-loop therapies, possibly allowing for the development of a fully closed-loop system without the need for user-initiated prandial insulin dosing," Thabit and Hovorka wrote.
Disclosures
Hood disclosed having patents and patent applications related to closed-loop systems. He also disclosed relationships with Eli Lilly, Novo nordisk, B. Braun, and Medtronic.
Thabit disclosed no conflicts of interest.
Primary Source
Diabetologia
Thabit H, et al "Coming of age: the artificial pancreas for type 1 diabetes" Diabetologia 2016; DOI: 10.1007/s00125-016-4022-4.