Medical Device Daily

There's no debate concerning what the “Holy grail“ of diabetes management and treatment will be: essentially an artificial pancreas. That technology will be a closed loop system connecting the continuous real-time assessment of blood glucose levels with some kind of pump to infuse insulin into the body in the right amounts, at the right time.

The complexity of glucose control makes it clear that this system won't burst upon us with one single breakthrough event. Rather, it is a road comprising a host of baby steps. But those baby steps are currently under way.

Thus, last week's approval of the STS Continuous Glucose Monitoring System from DexCom (San Diego) was hailed by the Juvenile Diabetes Research Foundation (JDRF; New York) as one of these steps important for reaching the ultimate goal.

Aaron Kowalski, PhD, director of strategic research projects for JDRF, said the FDA approval advances improved glycemic control, which he called “the key to reducing or even eliminating both short- and long-term complications of diabetes.“

DexCom's STS System consists of a tiny wire-like sensor that the patient can, himself or herself, insert just under the skin. The sensor continuously measures glucose levels which are transmitted wirelessly to a cell phone-like Receiver. With the push of a button, the hand-held Receiver provides the patient with real-time glucose measurements and trends, as well as providing auditory and vibratory alarms of high and low glucose levels.

In a conference call, Andy Rasa, president and CEO of DexCom, expressed a bit of pleasant surprise that the approval had come so rapidly.

He noted that rather than sending the standard “approvable“ letter, followed by a waiting period before granting final approval, the FDA had gone straight to issuing the approval notice.

He acknowledged that the company is currently scrambling to ramp up production in order to meet the orders that it expects. And he declined to report any details concerning pricing of the device, expected market penetration or future sales projections.

The results of a study on the DexCom STS published in the January 2006 edition of Diabetes Care, a publication of the American Diabetes Association (Alexandria, Virginia), demonstrated patients could achieve better control of glucose levels when using the information from the DexCom STS. That study concluded accuracy of the system over a 72-hour period, and that is the particular approval granted by the FDA.

Further out, Rasdal noted during the call, the company will be pursuing approval for use of the STS system for a seven day period.

The study reported also as “noteworthy“ that improvements in glycemic control “were observed within just six days of unblinded device use.“

JDRF's Kowalski said that a device such as DexCom's was particularly useful given the “wide swings in blood sugars,“ producing hyper- and hypoglycemia that those with diabetes experience. And a system that provides monitoring and alarm warnings of these swings is especially valuable for avoiding what can be life-threatening circumstances, he said.

“There's no doubt it my mind this offers a huge difference for people,“ he said.

Kowalski noted that the JDRF is interested in these technologies, no matter what company produces them, and so was glad to provide a supportive statement concerning the development at DexCom. “We're looking at the topic more than just the specific companies,“ he said.

Thus, he noted that JDRF is itself funding a research program focused on this at Yale University (New Haven, Connecticut), led by Bill Tamborlane, PhD.

Tamborlane's research has been to develop a “closed loop“ system that could be used in monitoring diabetes in children, he said.

And he said that the Yale group has produced “preliminary data that is unbelievable, extremely exciting to me.“ This effort is pushing forward using off-the-self products, primarily the Guardian RT (real-time) sensor from Medtronic MiniMed (Northridge, California) and a Medtronic insulin pump, Kowalski noted. (Recently FDA-approved, Medtronic has described the Guardian RT as currently in “limited launch.“)

These devices, Kowalski said, were put together with data delivered to a laptop and with an algorithm controlling insulin delivery. “The glucose levels that these guys get are better than 99.9% of those that people are getting with diabetes right now,“ he said, results which further point to achievement of the artificial pancreas system ultimately hoped for.

And he emphasized the inadequacy of much current technology in the area. Some studies, he said, have found that even those patients who were intensively managing their disease – measuring their glucose an average of nine times a day – spent less than 30% of the day in normal glucose range. The rest of the time their glucose was either too high, or too low.

But he said studies have found that patients using continuous glucose sensors spent 26% more time in normal glucose range and have statistically significant improvements in HbA1c levels, an important measure of longer-term glucose control.

Now, Kowalski said, a closed-loop system that helps to maintain a narrow control of blood glucose levels “is feasible“ with products currently available in the marketplace. The most advanced product, he said, will test glucose about 1,400 times a day, and this real-time information will provide guides for adjusting insulin infusion and the behavioral modifications required.

“The artificial pancreas is going to be a reality,“ he asserted, though adding the oft-heard caveat that the reality will require, still, a great deal more research.

Kowalski predicted that such a system is likely to be seen on the market “within five years.“

The steps toward it, he said, are likely to produce, first, a “semi-closed system,“ meaning some elements of the system implanted while other parts, such as controllers and monitoring devices, outside the body. Ultimately, a fully implantable system could be available to some diabetes sufferers.

The final steps to close the loop, commercially, will be Medicare reimbursement, he said – hardly big news to the device community.

Cynthia Rice, director of new technology access at JDRF, noted nearly 21 million Americans have diabetes. And she noted also one of the more important drivers requiring the final Holy grail system – the prediction that one in three children will some day develop the disease.

DexCom, Kowalski said, “puts another development into the field. And we look forward to other companies entering the space.“