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Next CGMS “Flash” FreeStyle Libre FDA Approved, Available Shortly

Nov 18, 2017

CGM will be available at lower price, without fingerstick calibration, and can be worn for 10 days with 12-hour warmup.

Abbott’s Freestyle Libre recently received FDA approval for use in the U.S.; it’s currently approved for  adults with diabetes only. The FreeStyle Libre sensor does not require any daily fingerstick calibrations. Real-time readings and trends can be used for insulin dosing.   


The Libre is expected to be available in U.S. retail pharmacies by the end of 2017. It’s expected to be sold for around $120 per month for three sensors (10-day use for each sensor) and each reader will be around $60 (one-time purchase); this is less than the cost of other CGMsS. The amount that insurance will reimburse is not yet known.

For the U.S., it has 3 major changes; it has a slightly shorter 10-day wear time, a much longer 12-hour warm-up after insertion, and it will require a prescription. What is interesting is that outside the U.S., FreeStyle Libre is 14-day wear, 1-hour warm-up, and does not need a prescription.

The longer warm-up period means when a new sensor is inserted, FreeStyle Libre will not show any real-time glucose data for the first 12 hours. During this time, users will have to use fingersticks with their monitor. It is recommended that patients put the sensor on before bed, which will get through much of the 12-hour warm-up for those who sleep close to eight hours or more per night. Sensors typically have the worst accuracy on day one, especially in the hours just after insertion. The longer 12-hour warm-up gives FreeStyle Libre more time to acclimate to the body, likely reducing the chance of less accurate readings right after insertion.  

To obtain uninterrupted FreeStyle Libre data, a patient could use two readers and alternate them, starting a new sensor’s 12-hour warm-up in the last 12 hours of the current sensor’s life. For instance, if a currently worn sensor is set to expire at 8:00 PM on Monday, the new sensor could be inserted 12 hours before at 8:00 AM on Monday. This new sensor would need to be started with a second reader. Once 8:00 PM rolls around, the current sensor will stop giving data just as the new sensor’s 12-hour warm-up is complete. (Note: the FreeStyle Libre reader can only be used with one sensor at a time, meaning a single reader cannot start the second sensor’s warm-up.)  Aside from wearing two sensors and managing two readers, the downside here is that data on each reader will only reflect half of a user’s total glucose data for that first day.  It’s unclear if the FreeStyle Libre software can combine data from two readers to create one unified data set. Abbott is working to reduce the warm-up time.

FreeStyle Libre is considered a continuous glucose monitor (CGM), since it collects a glucose value every minute and displays a number and trend arrow. However, it does not have alarms and does not communicate continuously with the handheld reader device as other CGM devices do. To obtain a real-time glucose number and trend, the sensor must be “scanned” (within 1.5 inches) using the reader device. This can be done through clothing, making it far less visible, obtrusive, and painful than a fingerstick.

The Libre sensor is approved for upper arm wear, is waterproof for showering and swimming, is fully disposable, is not affected by Tylenol (acetaminophen), and can store up to eight hours of recent glucose data on the patch. If more than eight hours pass between scans (e.g., 10 hours of sleeping), only the most recent eight hours of data will be captured. Abbott is working on a continuous communication version of FreeStyle Libre in partnership with Bigfoot Biomedical on their automation plans, which include a pivotal trial

At initial U.S. launch, FreeStyle Libre will not have smartphone connectivity. It will communicate only with the handheld reader device. Abbott may submit the LibreLink (Android) and LibreLinkUp (remote monitoring) apps for future FDA approval.

The Libre has been available in Europe since fall 2014 and is now used by more than 400,000 people across over 41 countries.

This approval comes one year after the product’s FDA submission. This real-time version may expand the U.S. CGM market significantly.

Abbott has set up a U.S. website at www.freestylelibre.us to provide additional information. Patients can sign up and also enter their healthcare provider’s information if they need assistance obtaining a prescription. (Sign up for updates here)

As a separate note, Dexcom submitted its next-generation G6 continuous glucose monitoring (CGM) sensor for FDA approval. A U.S. launch is expected sometime in 2018. It will be a 10-day wear sensor and possibly feature a one stick or no fingerstick calibration, a 30% smaller transmitter, and a new one-button inserter.  It is expected to have a 2-hour warm-up period

Practice Pearls:

  • Average measurement error relative to a reference value is 9.7%, an improvement from around 11% in Europe (and on par with 9.0% for Dexcom’s G5).
  • The device requires a 12-hour warmup period and can be worn for 10 days.
  • It is approved for those 18+ years with diabetes and requires a prescription.


Reference:  FreeStyle Libre System