A long-awaited upgrade of the FreeStyle Libre Flash Glucose Monitoring system from Abbott Diabetes has finally gotten the green light from regulators. The next-generation FreeStyle Libre 2 version features built-in Bluetooth to allow for optional real-time alerts for both low and high glucose levels, without the need to manually scan the sensor to trigger those alarms.

Previous versions of Libre did not include alarms, but only gave precise readings and trend arrows when users scanned the sensor worn on the arm. Now with Libre 2, users can be alerted automatically by the system if they are “out of range” (too high or too low). But to get a precise numerical reading, they still need to pick up the receiver and perform a scan.

The alarms add an important safety feature that helps put the Libre 2 more on par with other continuous glucose monitoring (CGM) products that alert users immediately if they are out of glucose range.

This much-anticipated announcement of Food and Drug Administration (FDA) approval came on Monday, June 15, during the American Diabetes Association’s 80th Scientific Sessions, held for the first time ever as a fully virtual conference due to the COVID-19 pandemic.

Our Diabetes Community has been eager for this news, since the Libre 2 first became available internationally in Fall 2018. It follows the original 10-day Libre sensor’s U.S. debut in 2017, the longer 14-day wear in mid-2018, and then the smartphone app scanning capability launched later that same year.

Abbott first filed the Libre 2 for approval in early 2019 and it’s taken more than a year to get through the regulatory review process. Here is a look at the new Libre 2, which FDA documents show was officially approved on June 12, 2020:

Scannable sensor: The sensor is a little white disc about the size and thickness of two stacked quarters that sticks onto your arm. Users just wave the handheld reader over the sensor to scan it and get readings. It’s currently approved for wear only on the upper arm, attached to the skin using an easy-push inserter device. That form factor and basic operation doesn’t change with Libre 2. With a one-second scan using a handheld reader, users can see their glucose reading, trend arrow, and eight-hour history. Like the previous version, Libre 2 has a one-hour “warmup” where it’s getting used to the person’s body before it starts generating glucose data.

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The Libre 2 sensor is stuck onto the upper arm for easy 14-day wear and scanning

Handheld receiver: Yes, a separate handheld receiver device is required. The Libre 2 receiver is blue rather than the traditional black (perhaps a nod to the built-in Bluetooth Low Energy?). Unlike the existing 14-day wear Libre that allows the use of a smartphone app for scanning, this new Libre 2 does not yet have that option. Abbott says it’s working to bring a mobile scanning app to the U.S. market ASAP.

New optional real-term alerts: If Libre 2 users have the real-time alerts activated, they will hear a beep or feel a vibration whenever their glucose levels go “out of range.” Users can adjust these settings for their own preferences on when they want to be alerted:

  • Low range: 60 to 100 mg/dL
  • High range: 120 to 400 mg/dL

This can help users stay safe, especially when sleeping, and alert them any time their glucose levels might need immediate attention. If you ignore an alarm, it will beep again in 5 minutes if the out-of-range condition still exists.

To be clear, to get an actual glucose reading or see the trend arrow on the direction your sugars are heading (like those on competing CGMs), users will still need to pick up the receiver and scan the Libre sensor.

No ‘routine’ fingersticks: As with the earlier model, the new Libre 2 is “non-adjunctive” or calibration-free. This means the FDA doesn’t mandate that users need to do a fingerstick test to confirm results before making treatment decisions, like insulin dosing.

Accuracy: We’re told the Libre 2 uses a slightly different algorithm that provides better accuracy in the first 24 hours of wear, compared to the earlier 14-day Libre sensor. This new generation has a combined mean absolute relative difference (MARD) of 9.3 percent total — or 9.2 percent for adults, and 9.7 percent for children. MARD is the standard measurement of CGM performance, and the lower the number, the better the accuracy. Abbott also claims that Libre 2 gets better accuracy on the lower end of the glucose spectrum, compared to other available CGMs.

Ages 4 and older: The FDA has approved this for kids as young as 4 years old, and adults with either type 1 (T1D) or type 2 diabetes (T2D).

Clinical studies: The latest data on the FreeStyle Libre system in general shows the technology is successful in helping people with both T1D and T2D stay in range, whether they’re using an insulin pump or multiple daily injections. One new clinical study out of France shows the Libre helped cut in half the number of hospitalizations due to diabetic ketoacidosis (DKA) — 52 percent for those with T1D, and 47 percent for those with T2D.

For more product details, you can check out this brief Libre 2 marketing video on YouTube.

Now that Libre 2 can alert users to highs and lows like the competing full-featured CGMs from Dexcom and Medtronic, practically speaking it offers much of the same advantages as those systems.

Using one of those competing products and getting a high or low alert would require the user to take similar action: stop what they’re doing to look at the smartphone or device display for the precise glucose result, and clear the notification. How someone uses that data to treat or dose insulin may vary afterward, no matter the device.

U.S. users of the existing Libre system have access to the LibreView online data-sharing platform, and we’re told Libre 2 data will be integrated there as well.

The LibreLink smartphone app used to scan the earlier Libre 14-day sensor has some pretty cool data-sharing and display features. So hopefully, it won’t take long for Abbott to offer a Libre 2 version of that mobile app as well.

Do-it-yourself tools: While not promoted by Abbott nor FDA-regulated, there are some do-it-yourself (DIY) options for the Libre system out there that provide workarounds to the core technology, adding alarms and options for smartwatch integration. Read all about those Libre hacks here.

The short answer appears to be: Not yet.

The Libre 2 has been granted the FDA’s “iCGM” designation, first granted to the Dexcom G6 in early 2018, allowing for interoperability between diabetes devices. But this new Libre 2 has one big restriction tied to it: the FDA approval specifically notes that it must not be used with emerging Automated Insulin Delivery (AID) systems, aka closed loop technology.

That’s a key difference from the Dexcom G6, the first-ever iCGM device that is sanctioned to work with AID systems. Currently, Tandem’s t:slim X2 insulin pump and its latest closed loop algorithm is the only system OK’d by FDA to work with these iCGMs.

While we haven’t been able to get anyone at Abbott to confirm this, industry observers believe that interoperability designation is what held up FDA approval of Libre 2 for quite some time. It seems Abbott may have underestimated what would go into obtaining the iCGM status. And now they have it, but with the restriction of no AID integration for now.

Suspicion is that FDA wasn’t comfortable with AID being tied to a system that doesn’t automatically provide an actual glucose number (because users must scan for an actual glucose result).

Nevertheless, offering optional real-time alerts is an important step forward.

Abbott is also developing a future Libre version that will provide a continuous stream of data without any sensor-scanning required. That version is what AID startup Bigfoot Biomedical has signed on to use in their future closed loop system, and likely what both Tandem and Insulet also have inked agreements to use for future iterations of their t:slim and Omnipod systems.

However, Abbott hasn’t provided any timeline for that next-gen product to hit market.

Abbott says the FreeStyle Libre 2 will be available in the coming weeks of Summer 2020 at participating pharmacies and durable medical equipment (DME) suppliers across the United States.

Notably, it will be available at the same price as the current Libre 14-day system, a suggested retail cost of $54 per sensor and $70 per reader. Cash prices vary based on the pharmacy, and of course insurance coverage can always factor in.

“From the start, Abbott designed FreeStyle Libre technology with affordability in mind,” says Abbott Diabetes Care Senior Vice President Jared Watkin. “We set a global price for our sensing technology that’s closer to that of traditional blood glucose fingerstick systems, and significantly less than other CGMs, because we wanted to make sure our life-changing technology was accessible to as many people as possible.”

Since it’s so newly approved, the Libre 2 will likely not yet be a Medicare-covered item for people with diabetes ages 65 and older. Hopefully, that won’t be too far off into the future, given that both the earlier Libre versions were already approved for Medicare coverage. Many are likely keeping fingers crossed that Medicare signs on to cover this latest device in 2021.

Once again, we have to applaud Abbott for continually improving on the popular FreeStyle Libre.