In what can only be described as a new chapter in diabetes technology, the first long-term continuous glucose monitor (CGM) that is implanted under the skin has now been OK'd for sale in the US.
On June 21, the FDA approved the Eversense CGM, a tiny device the size of a small pill that is implanted underneath the skin in the arm for 90-day wear -- unlike traditional CGMs that have a cannula insertion but are worn externally for up to 10 days before needing replacement. This approval came just a day before the big American Diabetes Association Scientific Sessions was set to start in Orlando, making Eversense a center of attention at the conference.
While Eversense has been on the market in Europe since May 2016 and is available in more than a dozen countries already, it took just about two years to get through the full FDA regulatory process. In April 2018, an FDA advisory panel recommended the Eversense for approval by the full agency, and it took two more months to get the official green light.
Importantly, approval for this smartphone-connected system is part of the FDA's new Software PreCertification Program, designed to enable accelerated regulatory review of mobile health technology.
“The FDA is committed to advancing novel products that leverage digital technology to improve patient care,” FDA Commissioner Scott Gottlieb said in announcing the Eversense CGM approval. “This approval of a more seamless digital system that gives patients the ability to effectively manage a chronic disease like diabetes is a vivid illustration of the potential for these mobile platforms. The FDA is creating a new and more carefully tailored regulatory approach for software products, including mobile medical apps, that will enable efficient oversight of these digital technologies and maintain FDA’s gold standard for product review. We’re advancing a more modern approach for these products that’s carefully adapted to the unique characteristics of these opportunities.”
Meanwhile, VP & US General Manager of Maryland-based Senseonics Mike Gill quips that their FDA approval happened to fall on Summer Solstice (the longest day of the year), appropriate given how it's the longest-lasting CGM sensor now available.
The Implantable Eversense CGM: What You Should Know
Here are the basics about this new diabetes tech:
- Tiny Sensor: The sensor is a tiny rod about the thickness of a Tylenol tab that's implanted completely under the skin. It's FDA-approved to go in the upper arm, though some PWDs internationally have reported having had it inserted on their abdomen. Once inserted, the sensor has a one-time warmup period of 24 hours.
- Doctor's Office Implantation: Insertion takes place in a doctor's office in a quick, less than 10-minute implant procedure. All that's needed is lidocaine and a specially designed tool to insert the sensor just underneath the skin in a little pocket about as deep as a regular CGM wire would be.
- Three-Month Wear (!): It currently lasts up to 90 days before needing replacement. The user returns to the doctor's office to have the sensor removed and a new one implanted in the other arm for rotation.
- Black Transmitter, Needs Charging: The rub for some folks may be the need to wear the transmitter on the skin, attached with an adhesive directly above the inserted sensor. The transmitter is a flat black disc not much thicker than two quarters -- smaller than an OmniPod patch pump but bigger than the FreeStyle Libre sensor. It sends data to the companion smartphone app every five minutes. The transmitter can be removed and re-attached as often as desired, for a shower or sports, but naturally no data will be transmitted while it is off. It also needs to be recharged daily for 10-15 minutes. The transmitter has a hard shutoff at 90 days based on an internal clock, so there is no possibility to restart an expired sensor.
- Fingersticks Required: This system still requires two fingerstick calibrations per day. We're told that Eversense plans to now work with FDA on next-gen tech that wouldn't require fingersticks, since the Dexcom G6 and Freestyle Libre with similar accuracy figures have paved that way.
- Light-Sensing Tech: The device uses novel, proprietary light-based technology to measure glucose levels. It's coated with a fluorescent chemical that when exposed to blood sugar, produces a small amount of light that is measured by the sensor.
- On-Body Vibration: One very cool feature is that the Eversense transmitter actually vibrates on the body to alert users to Highs and Lows, varying the amount of vibrations depending on where glucose levels are.
- Predictive Alerts: Along with the traditional Low, High and Rate of Change alerts, the Eversense can predict when you're going to go Low or High as much as 10-30 minutes in advance, providing those predictive alerts either via the on-body vibration feature or via the mobile app, which can give an audible alert or even flash a light to catch attention
- No Receiver, Smartphone Only: What's also novel is that this system does not include a separate receiver to carry around -- but that means you must have an Android or iOS device (iPhone, Android, iTouch, iPod, or tablet) -- to use it. While the straight-to-phone connectivity is an exciting trend, it's also a potential roadblock for some people.
- Data-Sharing: There are data-sharing capabilities through the Eversense mobile apps, available for both iOS and Android. There is the base Eversense mobile app that interacts with the CGM wearer has on their phone, in addition to a separate Eversense Now app that allows sharing of real-time data with up to 10 people.
- Adults Only (For Now): The Eversense CGM is only approved for ages 18 and older at the moment. However, Senseonics is already publishing data showing the safety and effectiveness in teens. Chances are approval for younger PWDs will materialize soon.
- Decorations! Oh, and even adults like a little bling, right? if you want to jazz up your little Eversense transmitter, word is there's at least one company making special skins and stickers to go on the device.
Safety, Efficacy and Usability
If you're wondering about safety and accuracy, Eversense was approved based on the so-called PRECISE II pivotal trial data from 2016. Senseonics studied 90 adults with both types of diabetes in 8 different spots across the US, and that clinical trial showed an 8.5% MARD result (measure of CGM accuracy) that pretty much measures up to other existing CGMs on the market. Reports of "adverse events" such as scarring or other issues related to the implantation showed up in only approximately 1% of those in the trial.
California endocrinologist and T1D himself Dr. Jeremy Pettus had the opportunity to travel overseas some months ago for insertion and wore the Eversense for a 90-day period. He shared this list with us of what he sees as the good and bad of this new implantable CGM -
- Super nice not to have to put on a new transmitter every week or so or worry about being out without one.
- Haven’t had to worry about a “bad” sensor, or getting question marks, or it falling off, or coming out.
- I like that I can take off the transmitter whenever I want and have nothing attached to me at all. When I put it back on, it starts reading again right away. You can’t really temporarily take off our currently available CGMs.
- It is at least as accurate, if not more so, than currently available CGMs, proven with the MARD score (measure of accuracy).
- Predictive high and low alerts are an option and can be set to alarm when you are going to go high or low in the next 10, 20, or 30 minutes.
- Love tht the Eversense also has cloud sharing capabilities.
- You have to charge the transmitter every day, which takes about 10 minutes. The charge does last ~42 hours in case you forget. I do it while taking a shower. If the transmitter battery runs out of juice your readings will be interrupted until you charge it.
- The charger for the transmitter is unique to the device so if you lose it, you can’t just go out and buy one (not like losing an iPhone charger or something). So, hopefully you can get an extra one when the device ships.
- The interface on the app needs to be more user-friendly. It does give you reports and so on, but they aren’t as slick as others we are used to and it takes a while to find the data you want.
- The insertion procedure, while not a big deal, is still a procedure and something you would have to schedule every 90 to 180 days.
Access and Cost
Senseonics says it's already taking pre-orders for the system. Currently the focus is training doctors, and for that purpose they've even created several mobile training units that are basically semi-trucks converted into pop-up educational centers that will tour the country. They're working with working with AACE (the American Association of Clinical Endocrinologists) on this trailer tour to both promote the device and train endos on the system.
They hope to get traction on training and complete all the needed marketing materials in order to go into full launch mode by the end of July.
Despite the fact that this is a specialized device requiring doctor's insertion, a big goal of Senseonics is to make CGM technology more widely available and accessible to people with all types of diabetes.
Rather than going through Durable Medical Equipment (DME) suppliers or pharmacies like traditional CGMs, Senseonics' Mike Gill tells us the Eversense CGM has its own specific billing code (#0446T) that clinics can submit for insurance coverage.
He says annual coast for the system (4 sensors and 1 transmitter) including insertion/physician fee will be roughly $5,000 to $6,000 depending on geography. Gill says the company plans to arrange for doctors to be able to work through the initial order and billing process for reimbursement, and then schedule three patients in a row so those clinicians can establish "muscle memory" on the procedure.
Based on what Senseonics has said publicly and the current state of regulatory approvals, Dr. Courtney Lias at the FDA says she expects the company to soon ask the agency for that "non-adjunctive" designation, to do away with the need for fingerstick calibrations.
We also expect to see their longer-wear version submitted for FDA approval at some point soon. That one's dubbed Eversense XL, which lasts for 180 days, and has already been on the market overseas since 2016.
Meanwhile, Senseonics has been part of the iCL (International Closed Loop trial) working toward developing future "artificial pancreas" systems using its CGM. And in early June 2018, Beta Bionics and Senseonics announced they'd be integrating the Eversense CGM in the iLET "bionic pancreas" device, which is in development and will eventually offer a closed loop system delivering both insulin and glucagon. While Beta Bionics is also partnered with Dexcom in a similar way, it's great to see this exploration of using a novel implantable device.
Congrats, Senseonics! We can't wait to see how our D-Community reacts to this first-ever implantable product and what their real-world experiences look like.