Echo Therapeutics, Inc. (Echo) has announced positive results of a clinical study of its Symphony tCGM System in patients with Type 1 and Type 2 Diabetes. Echo’s non-invasive Symphony tCGM System consists of its wireless transmission and transdermal biosensor technologies and its Prelude SkinPrep System, which incorporates leading-edge, needle-free, controlled skin ablation.
Echo’s Symphony tCGM System is designed to provide patients with diabetes and critical care patients with a reliable, affordable, and easy-to-use, needle-free continuous glucose monitoring device. The purpose of the study was to test the performance of its new, improved one-piece, cost-effective and easy-to-use biosensor.
“This study represents another major step forward in our Symphony development program,” stated Patrick Mooney, M.D., Echo’s Chairman and CEO. “We believe that we have successfully developed a new costeffective, one-piece biosensor and, with this study, we have demonstrated improvement in the accuracy of our Symphony system glucose readings.
Data from this study demonstrates that Symphony, using the new, improved, cost-effective biosensor, is safe, accurate and reliable at monitoring glucose levels. We look forward to continued progress with our Symphony development program throughout this year and next as we move toward our goal of making Symphony available to patients.”
After Prelude skin ablation, 10 Symphony tCGM biosensors were applied to subjects with Type 1 or Type 2 Diabetes. Venous reference blood samples were taken from intravenous lines at 15-minute intervals for 24 hours and measured on a YSI 2300STAT PLUS laboratory analyzer. At the conclusion of the 24-hour study period, the test skin sites were inspected for redness or any other undesirable effects.
CGM performance is evaluated with multiple analytical tools, as defined by the Clinical and Laboratory Standards Institute’s POCT05-A guideline. The primary metric, used to evaluate clinical accuracy, is the continuous glucose–error grid analysis (CG-EGA). The CG-EGA is a categorization of all data pairs based on the clinical significance of the accuracy.
Accurate readings result in the same clinical decision when based on the CGM trend vs. the underlying blood glucose fluctuations. Benign errors lead to the same clinical outcome as accurate readings even though the actual clinical decision may differ. Erroneous readings lead to clinical errors. CGM performance is measured as the sum of accurate readings and benign errors.
Numerical accuracy is the other key method for evaluating CGM performance. The most widely accepted tool is mean absolute relative difference (MARD). MARD is a standard error calculation tool that is used to measure the average absolute value of the relative (or percentage) difference between two measurements.
Using approximately 900 Symphony tCGM glucose readings paired with reference blood glucose measurements, CG-EGA revealed that the accuracy of the Echo’s Symphony tCGM System, measured as a percentage of accurate readings and benign errors, was 97%. The MARD for the study was 12.89%. There were no adverse events reported from the Prelude skin permeation or the Symphony tCGM biosensor.