In very big news for the Diabetes Community, Tandem Diabetes Care’s much-anticipated Control-IQ system for automated insulin delivery (AID) has been cleared by the FDA!
Control-IQ combines Tandem’s touchscreen insulin pump with the popular Dexcom CGM (continuous glucose monitor) and a smart algorithm that not only auto-adjusts basal rates for both high and low blood sugars, but also allows for automatic corrections for unexpected highs to get the user back in range.
On Dec. 13,
This will be the most advanced commercial “closed loop” system available, leap-frogging Medtronic Diabetes’ first-to-market Minimed 670G Hybrid Closed Loop that only adjusts background basal rates but doesn’t support automatic food or correction boluses. This advanced Control-IQ feature comes just about a year after Tandem launched its Basal-IQ tech, which predictively suspends insulin if it foresees an impeding low blood sugar.
Tandem’s Control-IQ is the second-ever FDA-cleared closed loop, and the only Dexcom CGM-compatible system to date, since the Medtronic system only works with that company’s own continuous sensor.
“Control-IQ clearance isn’t a step for automated insulin delivery, it’s a leap!” Tandem Diabetes CEO John Sheridan said.
The features of the system are as follows:
Touchscreen t:slim X2: The system uses the t:slim X2 insulin pump platform, with a sleek touchscreen and capability to be remotely updated from home, so that customers don’t have to trade in for a new piece of hardware every time some functionality gets upgraded. The t:slim X2 form factor is not very different from the earlier t:slim models. (More basics on the pump itself can be found at Tandem’s product page).
Glucose Prediction with Dexcom G6: Like the Basal-IQ launched in 2018, this new Control-IQ also uses Dexcom’s latest G6 CGM model. It does not require additional fingersticks for calibration as previous CGM generations do, as the FDA has designated the G6 accurate enough to replace fingersticks in making insulin dosing and treatment decisions. The CGM data is displayed directly on the t:slim X2 pump touchscreen with all the typical graphs and displays showing the current glucose level, along with data going back 3 to 24 hours.
Auto Insulin Shutoff and Resume: Like Basal-IQ, this latest Control-IQ feature automatically shuts off insulin delivery when the CGM level is predicted to drop below 80 mg/dL or if the glucose is currently below 70 mg/dL and falling. Instead of automatically stopping delivery for a set period of time, the system immediately resumes insulin once BG values are repeatedly back in range and rising again.
Basal Adjusting: Unlike the first-gen Basal-IQ system, in which Tandem tech just shuts off insulin for Lows, this new Control-IQ has the ability to auto-adjust basal rates to help keep users in range — both on the Low and High end of the glucose spectrum. The smart algorithm behind this Control-IQ feature was acquired by Tandem Diabetes years ago from the startup TypeZero Technologies (before Dexcom acquired TypeZero).
Target Glucose Range: Control-IQ has a fixed target, depending on the time of day –
- Normal target range of 112.5-160 mg/dL
- More aggressive range of 110-120 mg/dL, through an optional “Sleep Activity” mode where you won’t get any auto-correction boluses during those times.
- An optional “Exercise Activity” mode allows for a target of 140-160 mg/dL
Auto-Correction Boluses: Significantly, Control-IQ also offers automatic correction doses once per hour during the day. So if your glucose is predicted to go over 180 mg/dL, it will trigger a bolus that’s approximately 60% of the calculated correction amount with a target of 110 mg/dL. This works on top of the self-adjusting basal rates already in play. Control-IQ doesn’t automatically make boluses doses for meals (users still have to do that) but this auto-correction function can help reduce High blood sugars more quickly if a meal bolus is missed or calculated incorrectly.
Mobile App: Yes, Tandem’s long-awaited new mobile app is being launched in conjunction with Control-IQ! We first heard this was on the horizon back in mid-2017, but now it’s finally ready for prime time and will be compatible with iOS and Android. The first version will only allow for automatic wireless uploads to Tandem’s t:connect software — which is a nice feature because it takes away the need to attach a mini-USB to a laptop for uploading! Later, we’re told app enhancements will allow users to view pump status and alerts on their own phones, along with allowing remote monitoring by caregivers. Tandem says they’re planning the next major app enhancements for second half of 2020. It’s TBD when the app may move to the level of offering phone-control for the t:slim X2, as FDA is still mulling medical device control via smartphone. Up until now, the only app Tandem has offered is the “t:simulator” demo version.
Ages 14 and Older (for now): At launch, Control-IQ will be approved only for a patients age 14 and older. However, Tandem’s had a pediatric clinical trial for ages 6+ ongoing since mid-2019 and that is expected to wrap up in March 2020. Based on those results, the company says it plans to ask FDA to lower the age designation in Spring 2020. Of course, many may ask their healthcare providers about “off-label” prescriptions that could be an option.
Control-IQ Clinical Data: Tandem has presented data from clinical studies on this system throughout 2019. It was part of an NIH-funded study that was the first large-scale, six-month AID study of its kind that included a dedicated control group — increasing the clinical significance of the study results. This study for ages 14-71 showed impressive results:
- During the day, Time in Range (TIR), defined as between 70 mg/dL – 180 mg/dL, increased by 2.6 hours overall, or 71% daily compared to 59% for those not using Control-IQ.
- Overnight TIR was 76% compared to 59% for non-users.
- The system was used in active closed loop mode 92% of the time, and most impressively 100% of the 168 people using Control-IQ completed the trial and opted to keep using the system afterward — a positive wave the company hopes will continue in real-world use. (Notably, a smaller Stanford ‘real-world’ observational study on Medtronic’s Minimed 670G showed that as many as 46% of people using that device opted to discontinue use within a year because of the system complexity and perceived burden.)
- Tandem’s pediatric Freelife-Kid AP study took place in France and included 120 T1D kids ages 6-12 years. Rresults were just as impressive, with TIR increasing from 60% to 72% during the day overall and to 83% overnight. No severe hypos were reported, either. The Control-IQ active closed loop mode was used on average 87% of the time.
Tandem tells us that with Control-IQ, they have also addressed a few common user complaints about certain limitations of the existing Basal-IQ technology:
No Manual BG Entry: With Basal-IQ, users still had to key in blood sugar results manually, but now Control-IQ will use the actual Dexcom G6 CGM data that’s already integrated and displayed on the pump screen.
Extended Bolus Cancellation: Previously, if you programmed a bolus dose to stretch out over a period of time but then had a predicted Low during that timeframe where the system suspended insulin, you lost any of the remaining extended bolus that hadn’t yet been delivered. Not anymore. Control-IQ will now keep track of that undelivered part of an extended bolus, allowing for it to be delivered once basal insulin resumes.
Insulin While Low: With Basal-IQ, the system resumes insulin delivery as soon as there is a single CGM reading showing glucose levels are rising. But with Control-IQ, basal insulin delivery stays off until you’re back in range at or above 70 mg/dL, and it can even increase basal rates if the CGM data shows you’re rising too fast and approaching the High threshold.
Tandem is taking a few weeks to continue training healthcare providers before starting new pump customers and allowing for remote device updates for Control-IQ. The company says Control-IQ will be available starting in mid-January 2020.
You will need a doctor’s Rx to get an authorization code, and once that’s sent in to Tandem, it will trigger an online training module and quiz users will have to complete and pass in order to obtain Control-IQ. If they pass, the person will receive a unique download code to key in for updating their existing pumps with Control-IQ software, using the Tandem Device Updater tool online. That code is unique to the specific t:slim X2 device, so it’s not a code that can be shared between different users.
From what we’ve heard, the training aspect was a sticking point for FDA regulators: Tandem pushed for the online training (which in theory would allow for quicker, easier remote updating of their devices) versus requiring an in-person appointment with a healthcare provider to get training and obtain a code for the new Control-IQ prescription.
Also note that users will not be forced to upgrade; Tandem will continue offering Basal-IQ as an option for people who prefer a system designed specifically to help prevent Lows. But you can’t switch back and forth either. Tandem tells us their Updater function is not designed to toggle between Basal-IQ and Control-IQ.
In a big move, Tandem has announced that Control-IQ will be offered as a 100% free software update for in-warranty t:slim X2 pump users in the U.S.! This will be available to anyone who already owns an X2 pump, as well as anyone who purchases a Tandem t:slim X2 in the U.S. any time before Dec. 31, 2020. The download also offered through the Tandem Device Updater, which is simple to use by just plugging a micro-USB cable into a computer.
Outside of that free offer, the retail (cash) cost of the Tandem t:slim X2 pump with Control-IQ is$4,000, but Tandem says health insurance typically covers 80% of that cost.
Remember, you still need to purchase all the Dexcom G6 CGM supplies separately. While insurance coverage may vary, the retail price would be $237 for a single G6 transmitter that lasts three months and $349 for a box of three 10-day sensors. Since the Tandem t:slim X2 operates as the “receiver” connecting to the G6, it’s TBD on whether you’d need to actually purchase a separate Dexcom CGM receiver unit, as well.
Across the Diabetes Community, the response to this FDA approval news was very celebratory.
JDRF’s CEO Aaron Kowalski (a longtime T1 himself) said: “Regulatory authorization of the Tandem Control-IQ algorithm for use as part of a hybrid closed-loop system is a huge win for the type 1 diabetes community and a critical step forward in making day-to-day life better for people living with the disease.”
Meanwhile, the FDA issued a statement about the long-term effects of this decision. “The marketing authorization of this first stand-alone interoperable automated glycemic controller also allows substantially equivalent controller technologies that are developed for diabetes in the future to go through the 510(k) review process, helping to promote timely patient access to innovative technologies that can improve their care and quality of life,” said Dr. Tim Stenzel, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health.
Bottom line: That means accelerated regulatory review for more AID systems and their components coming down the road.
We’re also hopeful to see Tandem take this latest technology coupled with its impressive clinical data to insurance companies, to illustrate why it’s so important for patients to have coverage of these automated systems.
This can maybe help offset the vendor lock-in on some insurance formularies — like United Healthcare (UHC), which entered into a “preferred brand agreement” with Medtronic Diabetes that limits choice of suitable therapies for doctors and patients.
To us at the ‘Mine and many in the community, what makes this new Tandem offering most exciting is that it brings us competition and choice of commercially available closed loop technology. We’re thrilled to see Control-IQ approved and can’t wait to try it out for ourselves, and see what others think about this new automated insulin delivery option.