• Infusion sets remain “the weakest link” in insulin pump treatment, with as many as 60% of pump users reporting infusion set failures for a variety of reasons.
  • Past attempts at infusion set innovation have fizzled, including the short-lived BD FlowSmart sold by Medtronic.
  • Capillary Biomedical is working on a novel infusion set aiming to offer better reliability, longer wear and reduced patient burden.
  • Startup DiaTech Diabetic Technologies is developing a new built-in sensor to monitor, detect and alert to leakages and occlusions when infusion sets are starting to fail.

With all the recent advances in diabetes tech, a simple reality remains: the infusion sets that critically deliver insulin under the skin are far from fail safe, and remain “the weakest link” in new systems for controlling blood sugar.

You might call infusion sets the Achilles Heel of insulin pumps — as these little contraptions made up of a small needle, plastic cannula and adhesive often get clogged or spring a leak, disrupting insulin delivery into the body. Without this, none of the fancy “closed loop systems” under development can properly help patients.

“The dirty little secret of insulin pumps is that we’re not getting insulin all the time,” says Dr. Aaron Kowalski, CEO of the JDRF and a longtime type 1 himself. “Infusion sets have been traditionally treated by the diabetes industry as a commodity – made and sold at the lowest price possible because that drives business.”

While past attempts at innovation in this area have faltered, new work is underway to disrupt traditional infusion technology, and give PWDs (people with diabetes) more insight into how well their current set is performing.

Over the years, various studies have shown a shocking 15-20% failure rate of infusion sets — either full shutdown or a partial failure where insulin isn’t being delivered as it’s supposed to.

A seminal PubMed article published in 2012 highlighted how very little the Medical Establishment knows about how often patients encounter these problems, due to a lack of good studies on the topic. “Reading pump wearer blogs… suggests that these are a frequent source of trouble,” the authors wrote.

Everything from skin reactions, infections, lipohypertrophy, and scar tissue causing absorption interruptions can get in the way of effectiveness. Beyond that, patients also experience issues like adhesive failures, kinked cannulas or tubing, and user errors on insertion that can mess with insulin delivery.

Other problems stem from simple daily encounters with “doorknobs, cats, large boxes, children, gravity, and seatbelts,” noted Mark Estes of Capillary Biomedical, during a comprehensive presentation he gave on infusion set tech at our recent 2019 DiabetesMine University event.

Clearly, infusion set failure is a widespread issue.

A few years ago, pharma giant BD introduced their promising BD FlowSmart infusion set to address many of these concerns. It was FDA approved in May 2015 and launched via a partnership with Medtronic as the ‘Minimed Pro-Set.’

It had the smallest catheter on the market and included an extra hole or “side port” — basically an alternate route for the insulin to flow in case the first path was blocked. That was supposed to reduce flow interruptions and silent occlusions (blockages), hopefully reducing unexplained glucose highs for users.

Unfortunately, reports of kinked cannulas led to the initial product being pulled from market by Medtronic. They worked with BD to study the problems and planned to re-launch this infusion set, but eventually BD scrapped the concept completely.

Since then, the infusion set universe has been pretty still, without any new advances emerging. But at least two companies have been quietly working on innovations.

Capillary Biomedical, a startup in Irvine, CA, is a spin-off of the Artificial Pancreas Center at the Sidney Kimmel Medical College of Thomas Jefferson University in Philadelphia, PA.

They’re developing an infusion set that can be worn for 7 days or more that promises to deliver insulin subcutaneously in a consistent, reliable and safe way with a dramatic reduction in errors. If successful, this would more than double the current (3-day) wear time of existing sets — saving PWDs money and a lot of hassle!

Cap Bio’s impressive roster of leaders include researcher Dr. Jeffrey I. Joseph, who among other things was a partial founder of (now-defunct) insulin pump company Animas and led testing of its infusion set technology back in the day. At Cap Bio, he’s helping develop a prototype catheter that can be used to further study insulin delivery.

The team also includes Paul Strasma, whose experience goes back to Abbott Diabetes Care, and the esteemed Mark Estes, a diabetes industry veteran for three decades who was part of Minimed insulin pump team in the late 80s and later part of Asante Solutions that developed the Snap pump before its closure in 2015.

At our recent DiabetesMine University innovation summit in November 2019, he unveiled details about Cap Bio’s under-development “SteadiFlow” set:

  • would last for 7 days initially, and eventually even longer reliable wear-time
  • has a flexible, kink-proof cannula made of soft nylon (versus Teflon) to improve reliability and comfort, and reduce inflammation response
  • has three side ports to spread out insulin delivery, which reduces burden on body tissue and blood vessel capillaries and provides alternate paths in case blockage occurs in one port
  • goes in under the skin at a 35-degree angle for comfortable insertion
  • offers a one-handed inserter device, allowing flexibility of site locations
  • uses hidden a hidden needle designed for sharps self-containment and disposal after use

Estes says the SteadiFlow set design is complete and the company is currently conducting clinical trials outside the US, with plans to bring studies to the States soon in preparation for FDA filing. The hope is for market introduction within a couple years.

We’ve also been watching DiaTech Diabetic Technologies, a small Tennessee company developing something called SmartFusion, described as a sort of “CGM for infusion sets” that could continuously alert users to errors in real-time.

It’s a thumb-drive-sized fluid pressure sensor for insulin pumps that monitors, diagnoses, and predicts irregularities and problems in insulin delivery, and sends malfunction alerts to PWDs through an audio or Bluetooth connection.

Stats on the company website are telling: with more than 120 million infusion set used worldwide there are an estimated 60% of pump users experiencing infusion set failures regularly, leading to $426 million (!) in waste each year infusing insulin into un-viable sites.

DiaTech’s stated mission is to change that: “We want our system to know the exact time at which their infusion set needs to be changed. Our biggest differentiator is our system’s ability to do insulin delivery monitoring, allowing us to bring enhanced malfunction detection to patients. DiaTech aims to revolutionize insulin delivery monitoring and minimize loss of insulin from failed sites.

Founded in mid-2018, DiaTech has been making appearances at various diabetes conferences over the past year, after its initial money-raising efforts started gaining steam. One of the company’s four co-founders is John Wilcox, who was diagnosed with type 1 diabetes himself at age 9 in 2005. His own experiences led him to the healthcare field and volunteer work in children’s diabetes, before his start on the bio-tech side.

“Personally, I have had issues going into DKA because of insulin mis-delivery,” Wilcox said during a mid-2019 interview with the Lyfebulb blog. “I went to an endocrinologist in college who blamed me for poor A1C control rather than it being a technology/pump failure. I want to provide technology that can deliver alerts before hyperglycemia, because it happened to me and it is very dangerous. Fixing this unmet need of pump reliability can take one thing off the list of what patients and caregivers go through regarding issues with diabetes care.”

DiaTech’s Chief Scientific Officer JC Gray also tells us that much of his own work studying subcutaneous insulin infusion delivery in school, combined with industry work by those like Capillary Biomedical, inspired the creation of this new SmartFusion technology — which remains in early development stages.

If all goes according to plan, DiaTech’s Gray says they hope to do a limited release of SmartFusion infusion sets in Fall 2021.

Honestly, even as I write this post, my fists are clenching in agreement about how infusion sets are indeed “the weakest link.” They’ve been a huge factor in my decision-making on whether I want to use an insulin pump and (eventually) any pump-based closed loop technology.

After being off an insulin pump for over three years, I returned to pumping with the Tandem t:slim X2 in mid-October. While that device with Tandem’s Basal-IQ tech is great, the most frustrating aspect of using this technology is the infusion sets.

Whether I’m using an angled 45-degree set, with either manual or auto-serter, or the 90-degree “insertion pods” that have everything inside the plastic case, I always worry about the integrity of the tubing and cannula.

Every time I insert a new infusion set, I hold my breath and hope that nothing will go wrong. I also remain anxious for the first couple hours after a set change, watching my CGM data closely to make sure my sugars aren’t rising as a result of a hiccup with the new set.

Anything to improve this process and eliminate some of this worry and burden for PWDs would be a welcome addition to our diabetes toolbox, IMHO.