The World Health Organization (Geneva, Switzerland) estimates that more than 180 million people worldwide have diabetes and that number is likely to more than double by 2030. It's a huge market that a slew of companies are attempting to serve with easier-to-use, non-invasive glucometers so that patients can better manage the disease.

Echo Therapeutics (Franklin, Massachusetts) – one of the competitors in the heated race to serve this growing market – has reported positive results of a clinical study of its Symphony Transdermal Continuous Glucose Monitoring (tCGM) System in patients with Type 1 and Type 2 diabetes and will now sprint to conduct pivotal studies in early 2009, with expectations of filing a PMA with the FDA by mid-2009.

The non-invasive Symphony tCGM System consists of wireless transmission and transdermal biosensor technologies, and the Prelude SkinPrep System, which incorporates needle-free skin permeation control. The Prelude sensor sits on top of the skin, which is prepped through gentle dermabrasion or an ultrasound based method.

Echo's Symphony tCGM System is designed to provide both diabetics and hospital patients with a reliable, affordable, comfortable-to-wear, easy-to-use and needle-free continuous glucose monitoring device.

"Blood glucose measurements should become the fifth vital sign," Echo Chairman/CEO Patrick Mooney, MD, told investors during a conference call yesterday. "Diabetic complications are the result of patients not keeping tight control over their glucose levels. It's estimated that the global glucose monitoring market is $7 billion and is significantly under penetrated. In the diabetes market, finger-stick glucose monitoring is the standard of care for managing one's glucose levels."

And even though it's recommended that diabetic patients check their glucose levels four times a day, the invasive fingerstick is enough to dissuade many. For those who do follow the recommendation, it's just a snapshot of a patient's glucose level at a point in time.

"Physicians acknowledge that more frequent testing will lead to better outcomes," Mooney said. "Data from this study indicate that Symphony – using our Prelude system – safely, accurately and reliably monitored glucose levels in patients with Type 1 diabetes."

In the study, after Prelude skin permeation, Symphony tCGM biosensors were applied to 10 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.

The primary statistical analysis tools used to evaluate the performance of the Symphony tCGM System relative to the reference measurements were the Clarke error grid, mean absolute relative difference and linear regression, each of which are widely used to evaluate the performance of glucometers.

The Clarke error grid is a plot of all data pairs categorized into five discrete areas: A, B, C, D and E. The A and B areas are the most clinically desirable zones and D and E are the least clinically desirable zones. Devices with a higher combined A and B zone percentage (closer to 100%) and lower combined D and E zone percentage (closer to 0%) are considered to have better performance.

Using 1,292 reference blood glucose measurements from the 10 subjects in the study, Clarke error grid analysis of the study data showed that Echo's system had approximately 99% of the data in the combined A/B zones, with 76.4% in the A zone and 22.4% in the B zone, and only 0.2% and 0.9% in the C zone and D zone, respectively.

There were no adverse events reported from Prelude skin permeation or the Symphony tCGM biosensor.

Mooney said a detailed analysis of these data will be presented in a peer-reviewed setting in the near future.

The company plans to initiate internal confirmatory studies during 3Q08 and pivotal studies will start during the 1Q09.

"Given that we have unencumbered ownership of Prelude, we plan to be aggressive in our corporate partnering discussions as we advance the product through clinical studies," he said.

Earlier this year, Echo reported positive results from a pilot study of its Symphony tCGM system in a trial conducted at the Tufts Medical Center (Boston). That study was designed to evaluate the performance of the Symphony system, including the use of its ultrasound-based skin permeation system and biosensor technology incorporating hydrogel chemistry.

The study enrolled 25 adult patients scheduled for elective cardiac surgery and included both intra-operative and post-operative continuous monitoring of blood glucose levels (Medical Device Daily, March 24, 2008).

Other non-invasive monitors under development include:

OrSense (Nes Ziona, Israel) reported receiving CE-mark approval for its NBM-200G non-invasive continuous blood glucose monitor last summer. The NBM-200G is based on OrSense's technology that allows non-invasive measurement of analytes, including glucose, hemoglobin, and oxygen saturation with very high sensitivity.

The device is operated by placing a ring-shaped probe around the patient's finger, which applies a gentle pressure to the finger, similar to that applied during blood-pressure measurement. Optical elements in the sensor perform a sensitive measurement of the light transmitted through the finger. Called Occlusion Spectroscopy, this method provides a quick, accurate and painless measurement of the patient's blood glucose (MDD, June 22, 2007).

Georgetown University (Washington), Gentag (also Washington) and Science Applications International (San Diego) have combined forces to develop a non-invasive method for glucose measurement. The three agreed to combine their respective intellectual property and expertise to create a new method to monitor glucose, using disposable skin patches with wireless sensors and cell phones (MDD, June 20, 2008).

First results from a proof-of-concept study of 10 diabetes patients confirmed the viability of the everyday monitoring for a novel Swiss multi-sensor device for non-invasive glucose monitoring. Patients logged 110 days wearing the sensor-loaded armband from Solianis Monitoring (Zurich, Switzerland) that captured data from 10 standard blood glucose measurements each day. Though the data is transferred wirelessly to a standard pocket computer, there is no display of information for the patient and the data is sent to Solianis each evening for analysis (MDD, June 18, 2008).

GlucoLight (Bethlehem, Pennsylvania) last summer reported its best study results to date with its continuous, noninvasive glucose monitor, the Sentris-100 – non-invasive being the key term here. The study yielded a number of important results regarding the performance of the device, now in its fourth generation. The Sentris-100 is the only continuous, noninvasive blood glucose monitor for the acute-care environment that is in clinical trials, according to GlucoLight (MDD, Aug. 28, 2007).