Share on Pinterest
Image via Medtronic Diabetes

For the first time in the United States, people with diabetes will soon have access to an insulin pump infusion set that can be worn on the body for up to 7 days — compared to existing sets that must be changed out every 2 or 3 days.

Medtronic Diabetes received approval from the Food and Drug Administration (FDA) in July 2021 for its extended-wear infusion set, designed to last more than twice as long as existing infusion sets that connect traditional tubed pumps to the body for insulin delivery.

Medtronic tells DiabetesMine that pricing isn’t yet available, but the company plans to launch this new product starting in early 2022.

This is important for people with diabetes because infusion sets have long been viewed as the weakest link in insulin pump therapy, a sort of “Achilles Heel” in this sophisticated technology. Some research has shown a 15 to 20 percent failure rate of infusion sets, either a full shutdown or partial failure that stops insulin from being delivered properly.

The shortcomings of infusion sets have become even more conspicuous with the development of automated insulin delivery (AID) systems, that dose insulin based on continuous glucose monitoring (CGM) readings. Most CGM sensors can be worn on the body for 7 to 10 days, so it’s burdensome that pump infusion sets must still be changed out every few days.

The promise of more reliable, longer-wear infusion sets such as this new Medtronic Extended set brings hope for a more seamless user experience.

“This first-of-its kind infusion set innovation introduces an exciting shift in the experience for people with diabetes — extending wear time so people can think less about changing out their sets, and, in turn, reducing burden in a meaningful way,” Bob Vigersky, chief medical officer of Medtronic Diabetes, said in a statement. “This is an area that doesn’t receive as much focus but is a very big component for pump users that impacts the overall experience and can help make living with diabetes easier.”

What’s an insulin infusion set?

An infusion set connects the insulin pump device to your body. It houses a tiny needle that punctures your skin to place a cannula (tiny plastic tube) under your skin in the subcutaneous fat to deliver insulin. The infusion set is connected to your pump via plastic tubing, available in different sizes and lengths.

How to choose

Medtronic suggests using a 6 millimeter (mm) cannula length if you have low or average body mass index (BMI); if you tend towards higher BMI, use the 9 mm cannula length.

If you wear your insulin pump close to your infusion site, 18″ or 23″ tubing is recommended. If not, then 32″ or 43″ tubing may be the best fit.

The new Medtronic Extended infusion set has been available in Europe since April 2021. It is manufactured by ConvaTec’s Unomedical, one of the world’s leading infusion set makers.

This new Extended infusion set introduces changes to the tubing’s material and a redesigned connector, to reduce the loss of preservatives, prevent tube occlusions (insulin clogs in pump tubing) and keep the insulin chemically and physically stable over time. Medtronic specifically points to a “novel and proprietary approach” that addresses insulin degradation, preservative loss and occlusions — all things that can result in disrupted insulin delivery and therefore higher blood sugars.

The extended-wear set also has a more skin-friendly adhesive designed to allow longer, more comfortable wear on the body. The company reports that participants in a 100-person European study commented on the new infusion set being more comfortable compared to their previous infusion sets, and saw this as a meaningful improvement that reduced the overall burden of insulin pump therapy.

Clinical data also shows that people using this new set might save 5 to 10 vials of insulin per year, because it eliminates the many units of insulin currently wasted by the requirement to change out an infusion set every few days. Less-frequent set changes also allow skin site locations to rest and heal, Medtronic points out.

All of these advantages were highlighted when Medtronic released early study data on the new set in June 2020, and again recently in June 2021 when the latest data submitted for FDA review was published.

Research presented by Dr. Bruce Buckingham of Stanford Diabetes Research Center at the American Diabetes Association Annual Meeting in June 2021 showed that Medtronic’s extended-wear set lasted the full intended wear time (7 days) for up to 75 percent of the 259 study participants, which beat out the 67 percent for the current 2- to 3-day sets.

This isn’t the first attempt at bringing forth a new type of infusion set to improve performance.

Pharma giant Becton Dickson (BD) and Medtronic rolled out the “Minimed Pro-Set” with so-called FlowSmart technology back in 2015. It had an extra hole or “side port” that was supposed to reduce flow interruptions, but it turned out to be a flawed product due to insulin blockages, and it was soon pulled from the market. BD later scrapped that idea entirely.

Since then, there are several other new infusion sets in the works, notably:

Southern California startup Capillary Biomedical is developing it own new 7-day extended-wear infusion set aiming to offer better reliability, longer wear and reduced patient burden. The company recently announced results from an Australian study showing that 88 percent of infusion sets featuring the company’s new “SteadiFlow” cannula technology lasted the intended 7 days — even better than Medtronic’s results.

Tennessee startup Diatech Diabetes is developing something called SmartFusion, a new built-in sensor to monitor, detect and alert to leakages and occlusions when infusion sets are starting to fail. It’s described as a sort of “CGM for infusion sets” that could continuously alert users to errors in real-time. In early September 2021, the company was awarded a $300,000 small business innovation grant for preclinical development from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

We’re happy to see the new Medtronic extended-wear infusion set as an option, and are of course routing for these startups to help usher in a next generation of reliable technology for insulin delivery.