Just a few weeks ago, the U.S. Food & Drug Administration (FDA) approved Medtronic’s 670G insulin pump for sale in the US.
It came as a bit of a surprise that the FDA turned around Medtronic’s application so quickly. Most insiders expected approval towards the end of 2016 or early 2017. Even Medtronic was caught a bit off guard – they just started shipping and training trainers on their 630G pump, and do not plan to officially launch the 670G until late winter/early spring. (I just trained my first patient on a 630G this week, and have a few more lined up in the next couple of weeks)
Almost immediately after the announcement about 670G, news outlets began the usual hyperbole, describing the system as an “artificial pancreas” capable of everything from curing diabetes to solving the world’s energy problems. Even JDRF, usually known for “keeping it real”, jumped on the holy-grail-of-pumps bandwagon. But before you flush your stock of insulin down the toilet, let me set a few things straight.
Medtronic’s 670G is NOT an artificial pancreas, and it is NOT a cure for diabetes.
It is a tool that, when functioning well and used by trained individuals, can do some of the decision-making to keep blood sugars within a reasonable range more of the time. OK, now exhale and read that last sentence again. A true “artificial pancreas” or “closed loop system” automates things entirely – manages the blood sugar extremely well all the time with little-to-no user involvement. The 670G meets part of that definition. It can “nudge” the basal insulin delivery upwards or downwards when blood sugar levels are heading towards highs or lows, and suggest correction boluses when needed. Between meals and overnight it can do a wonderful job of stabilizing blood sugars, as long as the sensor and pump are working correctly. Your brain still has to do the majority of the work: bolusing for meals, adjusting for stress and exercise, and maintaining all aspects of the system – not to mention every element of management when the system is not in hybrid closed-loop mode due to sensor change-outs or other system issues (pivotal trials showed this to be 12% of time for adults, 24% of time for adolescents).
In pre-release studies, both adolescent and adult users of the 670G saw a modest reduction in hypoglycemic events (and time in a low range), and a modest improvement in time spent within target range. Given that the system has a hard “target” blood sugar of 120 and errs on the side of preventing hypoglycemia, the average blood sugar amongst study participants was around 150. Average A1c came down from 7.4% to 6.9%. At the conclusion of preliminary studies, approximately 80% of participants chose to stay on the 670G system.
The 670G has a similar programming platform as the 630G (described in detail in the August, 2016 edition of Diabetes Bites). The main differences involve the sensor: It uses a new –generation sensor with enhanced accuracy and overall performance. The MARD (average discrepancy between sensor values and lab values) was 10-11% in the pre-market studies, which is considerably better than previous Medtronic sensors. And of course, the pump’s built-in algorithm makes automated adjustments when blood sugars are headed low (to prevent hypoglycemia) or above a high threshold (to reduce magnitude and duration of hyperglycemia). Medtronic has announced that those who obtain a 630G pump between now and the end of the year will have the opportunity to upgrade to the 670G for free.
What about other pump companies? All are working on similar systems, utilizing the highly-regarded Dexcom CGM and specialized algorithms that allow for a bit more customization. But all are still in the testing phase and will take at least a year before becoming available. The good news is that the FDA has stated their intention to move applications for hybrid closed loop devices (like 670G) through the process as quickly as possible in order to meet the needs of the diabetes populace.
The 670G is definitely a step in the right direction. I, for one, am eager to give it a test-drive. But it is really just a step… not a giant leap for diabetes-kind. More steps will surely follow, and when we add up those steps, it may represent the quantum leap we’re all hoping for. But until then, learn how to manage the right way. Count your carbs accurately. Check your blood sugar. Adjust for physical activity. Figure out the right basal and bolus settings. That way we don’t have to stand around waiting for a device to rescue us from the highs & lows of daily living.