Several times every day, many of the nearly 19 million Americans diagnosed with diabetes have to check their glucose levels. Even though this task can be life-saving, patients are often reluctant to do it regularly. Existing methods are either painful (pricking a finger for a blood sample) or cumbersome (implanted sensors that require frequent replacement). Joseph Y. Lucisano and David A. Gough believe they have a better way. They are the co-founders of GlySens Incorporated, and hold 18 monitoring and related technology patents. They have developed an implanted glucose monitoring system that can work for over a year before requiring a change. If successful, it will join a market projected to reach $568.5 million globally by 2020, according to Allied Market Research.
The GlySens system has two parts: A sensor, which resembles a thinner version of a milk bottle cap, that is implanted in the fatty cell layer under the skin. It wirelessly connects to an external receiver, which is slightly thicker than a cell phone. The receiver displays the current glucose level, recent history, trending patterns, and provides a warning when thresholds are crossed. Lucisano said that in a future iteration the receiver should be converted to a software application that can run on a cell phone. For now, a standalone receiver is the quickest path to market.
The design closely resembles the sub-cutaneous glucose monitor systems already available from several other companies, including DexCom, Medtronic, and Abbott (Note: older Abbott devices have recently been recalled.)
The crucial difference is that the sensors in the existing systems need to be re-calibrated several times a day and can only stay in place for a week at most. Leading vendor DexCom, for example, states that its G4 Platinum is “the only sensor on the market approved for up to 7 days use.”
By contrast, when brought to market, the GlySens ICGM™ long-term sensor system should work for a full year after a five-minute insertion under local anesthesia. The company has already conducted a successful six-person clinical trial for an earlier generation of the device. Despite the older device being nearly twice as large as the “bottle cap,” Lucisano said most of the subjects went for long periods of time during the trial where they forgot they had the device implanted.
Unlike competing systems, the GlySens sensor detects oxygen, which yields its unique stability. Glucose and oxygen flow from the bloodstream onto a membrane that covers an electro-chemical detector array. The membrane is primed with enzymes that interact with oxygen.
“By measuring the amount of remaining oxygen from the enzyme reaction, the device can calculate the extent of the enzyme reaction and therefore the concentration of glucose,” Lucisano said.
The lab-on-a-chip technology suggests the sensor should be modifiable to measure other metabolic states, which is just what the US Army asked the GlySens team to explore.
“We were able to demonstrate that the device could be adapted to monitor lactate — that’s of interest during states of high exertion — and oxygen as well,” Lucisano said. The team is investigating the device’s potential ability to detect other analytes as well.
The diabetes system should receive European market clearance next year, Lucisano said. The company hopes to apply for FDA approval after the completion of a larger clinical trial, likely in 2016. Currently, they are raising a third investment round to fund the clinical trial.
“What we hope to deliver to people with diabetes is freedom. To give them some time in their day when they can hopefully be free from remembering they have diabetes,” Lucisano said. “The more people that use our product and forget that they’re using it — that’s what we’ll count as success.”