Continuous Blood Glucose Monitoring in a Flash

Continuous Blood Glucose Monitoring in a Flash
Dema Mohammed, PharmD, Community-University Health Care Center

Background: On September 27, 2017, the U.S. Food & Drug Administration announced the approval of the FreeStyle Libre Flash Glucose Monitoring System (FSL-CGM), the first continuous glucose monitoring system which does not require a blood sample for calibration, thereby reducing the need for fingerstick testing in patients with diabetes. Most CGM systems on the market currently require at least two fingersticks per day. Prior to approval, the FDA evaluated data from a clinical study to review the device’s performance compared to laboratory analysis of blood glucose values. The device has been approved for use in other countries since 2014. 

How to Use: The FSL-CGM comes factory calibrated. Some patients may still use the results of fingerstick tests to assist in calibration of their meter and confirm their FSL-CGM blood glucose readings; however, it is not necessary. Fingersticks are required for treatment decisions when the “Check Blood Glucose” symbol appears on the device, when symptoms do not match the system’s readings, when readings are suspected to be inaccurate, or when experiencing symptoms due to high or low blood glucose. The fingerstick reading does not have to be on a FreeStyle product.

The FSL-CGM comes with a blood glucose monitor and small, round quarter-sized sensor worn on the upper arm.  The sensor has a small wire that is inserted into the skin in order to allow for continuous blood glucose measurements. A handheld mobile reader is moved over the sensor to obtain real-time glucose reading. The mobile reader illustrates trends with a directional arrow and allows review of data for the past 8 hours. Previously, this data was only retrievable by healthcare professionals, but now FSL-CGM users can view the data themselves. The FSL-CGM is specifically intended for use in patients 18 years of age and older. The sensor can be worn for 10 days prior to need for replacement (approved to be worn up to 14 days in other countries). The waterproof sensor is fully disposable and can be worn while showering and swimming. The sensor is water-resistant in up to three feet of water for a maximum of 30 minutes. 

Cost: FSL-CGM will require a prescription in the U.S and will be available in major retail pharmacies across the U.S. by the end of 2017 according to the manufacturer, Abbott Diabetes Care Inc. The expected cost will be around $120 per month for three sensors, the handheld reader will be a one-time purchase of around $60. Patients and providers can sign up on the manufacturer's website to determine when the FSL-CGM will be available at their nearest retail pharmacy. 

1. Goodin, T. FDA News Release: FDA approves first continuous glucose monitoring system for adults not requiring blood sample calibration. U.S. Food & Drug Administration. Published September 27, 2017.

2. Haak, Thomas, et al. Flash glucose-sensing technology as a replacement for blood glucose monitoring for the management of insulin-treated type 2 diabetes: a multicenter, open-label randomized controlled trial. Diabetes Therapy 8.1 (2017): 55-73.

3. Bolinder, Jan, et al. Novel glucose-sensing technology and hypoglycemia in type 1 diabetes: a multicentre, non-masked, randomised controlled trial. The Lancet 388.10057 (2016): 2254-2263.