Earlier this week, the FDA approved Medtronic’s hybrid closed-loop insulin delivery system for people with Type 1 diabetes, bringing the company one step closer to a fully automated, closed-loop system, or a true “artificial pancreas.”
The hybrid system continuously regulates a patient’s basal insulin levels using a sensor inserted just under the skin, the MiniMed 670G insulin pump, an infusion patch that delivers the insulin and an algorithm that, over time, learns the patient’s insulin needs. It is approved for patients aged 14 and up.
“It does very well overnight when people aren’t eating,” Dr. Bruce Buckingham, a professor of pediatric endocrinology at Stanford University and a study investigator, told FierceMedicalDevices. The system cuts down on the overnight work and the constant vigilance required to manage diabetes, Buckingham said. Some diabetics wake up in the night to test their glucose levels, but not John Caldwell, 45, of Hopkins, MN, who participated in a MiniMed clinical study.
“I wasn’t really maintaining my blood sugar at night--I had kind of given up on it,” Caldwell told FierceMedicalDevices. He typically woke with high blood glucose and it took “a good chunk” of the day to get it back within target range. With the MiniMed 670G, Caldwell said, he doesn’t have to worry about his blood glucose being too low or too high when he’s being active. He liked not having to think about maintaining background insulin levels, but added that it was challenging to step back from managing basal insulin after doing so for 30 years.
“It took a while to trust that the computer is going to take care of your blood sugar. … When I see it high, my natural reaction is to fix it, to do a correction,” Caldwell said. “With the system, you need to leave it alone and be less hands-on.”
But he wishes that the system would automatically deliver bolus insulin when he eats. What makes the MiniMed 670G a hybrid system is that a patient must manually request bolus insulin ahead of meals. Currently, a bolus takes about 20 to 30 minutes to affect glucose levels, so it’s recommended to give insulin about 10 minutes before a meal. Faster-acting insulin may be the key to making the hybrid closed-loop system into a fully automated one, Buckingham said.
As for the future of the “artificial pancreas,” the current system requires fingerstick confirmation before it delivers correction doses of insulin, Buckingham said. Future generations will probably do this based off sensor glucose values rather than requiring a fingerstick, Buckingham said. The hybrid system also lets patients set a higher target glucose range if they plan to exercise. Eventually, the system might include accelerometers and other ways to handle exercise and other events in life that can make managing diabetes more difficult, Buckingham said.
Medtronic plans to launch the hybrid closed-loop system next year: “The MiniMed 670G system will be commercially available in the spring of 2017 as Medtronic ensures payer coverage, market and manufacturing readiness, as well as appropriate training of employees, clinicians, educators and patients on the new system,” said Alejandro Galindo, president of Intensive Insulin Management at Medtronic’s diabetes division, via email.