FDA Plan for Developing Artificial Pancreas Pleases Critics

December 02, 2011

December 2, 2011 — Spurred on by diabetes advocacy groups and politicians alike to pick up its regulatory speed, the US Food and Drug Administration (FDA) yesterday issued preliminary recommendations to help, not hinder, researchers and manufacturers in their pursuit of the "artificial pancreas."

"Flexibility is one of the important hallmarks of this latest guidance," said Charles "Chip" Zimliki, PhD, head of the FDA's artificial pancreas working group, in a press conference yesterday. "We are really trying to get these devices to market as quickly as possible."

Not a manmade organ, the artificial pancreas consists of an insulin pump and a continuous glucose monitor (CGM) connected to a sensor placed under the skin of a patient with type 1 diabetes. Thanks to its sophisticated software, the system automatically doses the right amount of insulin based on the patient's glucose levels. An ultimate form of the system called "treat-to-target" would set a desired level for blood glucose and attempt to maintain it at all times, as opposed to merely staving off highs and lows in a "treat-to-range" approach.

Such a fully automated device would allow people with type 1 diabetes, especially children, to lead active lives without having to constantly check their glucose levels, according to the FDA.

Right now, US researchers are testing the artificial pancreas in inpatient clinical trials. At issue is how quickly the research can reach the stage of outpatient trials, which are already underway in other countries.

Groups such as the JDRF (formerly known as the Juvenile Diabetes Research Foundation) and the American Diabetes Association contend that an overly cautious FDA has prevented life-saving technology from reaching patients in a timely manner. They point to an early version of the artificial pancreas called a low-glucose suspend (LGS) system, which temporarily halts the flow of insulin when a patient's blood glucose dips to a dangerously low level. LGS systems are approved in more than 40 countries, according to the JDRF, but not in the United States.

In June, the FDA issued draft recommendations for the development and approval of LGS systems here, and the reviews were mixed. The JDRF and other groups stated that the clinical study pathway proposed by the agency placed too many unnecessary obstacles in the way of researchers. These organizations, along with Sen. Susan Collins (R-ME) and Sen. Jeanne Shaheen (D-NH), have pressed the FDA to make its promised guidance on the artificial pancreas less burdensome.

"Open to New Ideas"

In its announcement yesterday, the FDA highlighted how its draft guidance for designing and testing artificial pancreas systems gives researchers sufficient leeway while satisfying requirements for safety and effectiveness. The agency said that its guidance would, among other things:

  • give researchers maximum flexibility in determining the appropriate size, endpoints, and duration of clinical trials;

  • allow them to use data from clinical trials conducted outside the United States, as well as data on the safety and effectiveness of individual components of artificial pancreas systems, to justify a quick progression to outpatient trials; and

  • give researchers the option to either prove their system matches the glycemic control of standard therapies or demonstrate that it provides superior control.

In addition, the draft guidance, which is now open for public comment, envisions an artificial pancreas that could depend solely on a CGM for glucose measurement without the need for calibration checks with a separate device such as a blood glucose meter. Consequently, the FDA plan for evaluating artificial-pancreas systems places the "primary focus for glucose measurement" on CGMs.

The JDRF had criticized the FDA for not expressing a commitment to using CGM data in its draft guidance for LGS systems, so the agency's stance on the artificial pancreas represents a new one. During the press conference, Dr. Zimliki said the agency took the earlier criticism to heart as it developed its latest recommendations. He repeatedly emphasized that the FDA is "open to new ideas, new concepts, new approaches."

"We couldn't be prescriptive in this guidance," he said.

No Slam Dunk, Says One Expert

The diabetes care community is giving a preliminary thumbs up to the proposed guidance on the artificial pancreas, even as it digests all the details.

"Our initial review...indicates that the FDA has been responsive and listened to the recommendations of leading clinicians and researchers in the type 1 diabetes field," JDRF President and Chief Executive Officer Jeffrey Brewer said in the group's news release. "It also appears that the draft guidance lays out a rapid timetable to move from inpatient trials to prove the [artificial pancreas'] safety and efficacy, and if that turns out to be the case, it is good news."

In a news conference yesterday, Aaron Kowalski, PhD, assistant vice president of treatment therapies at the JDRF, said that the FDA's roadmap for developing an artificial pancreas gives the United States an opportunity to catch up with the rest of the world in this technology. "The potential is very big," said Dr. Kowalski.

Another diabetes expert who is encouraged by the FDA's draft guidance is Eric Orzeck, MD, an endocrinologist in Houston, Texas, who serves on the board of directors of the American Association of Clinical Endocrinologists. "My first reaction is that it is not as onerous as other FDA edicts have been," he told Medscape Medical News.

Dr. Orzeck, who began fitting patients with insulin pumps in 1978, said that the commercialization of an LGS system will set the stage for evaluating more sophisticated devices such as the artificial pancreas (a term he does not favor) that can automatically respond to spikes as well as dips in blood glucose. Advancing to that level of sophistication, however, will not be a slam dunk, he said. It will be a challenge to design insulin pump software that accounts for the effect of food intake and exercise on glucose levels, which varies from patient to patient.

"It will take time," said Dr. Orzeck. "I have a distinct feeling that to curtail a rise in glucose will be a tremendously difficult thing to do."

More information on the draft guidance is available on the FDA Web site.


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