CHICAGO – Use of a first-generation closed-loop insulin delivery system by patients with type 1 diabetes demonstrated the capability of maintaining safe glucose levels overnight, results from a small study demonstrated.
The findings, presented during the annual scientific sessions of the American Diabetes Association, indicate feasibility for continuing refinement of the system, known as the Hypoglycemia-Hyperglycemia Minimizer (HHM), developed by West Chester, Penn.–based Animas Corp., a Johnson & Johnson company. In June of 2011, Animas received Investigational Device Exemption for the use of the system in human clinical feasibility studies. For the current study, the HHM comprised an insulin pump, a continuous glucose monitor, and a control algorithm.
Daniel A. Finan, Ph.D.
"Avoiding hypoglycemia during the overnight period is a primary concern for people with diabetes," Daniel A. Finan, Ph.D., said in an interview prior to the meeting. "Maintaining safe glucose levels during this time frame is crucial in helping not only to achieve better control, but also to provide peace of mind to patients and caregivers."
Dr. Finan, a staff algorithm scientist at Animas Corp, reported results from a feasibility study conducted in 20 adults with type 1 diabetes and designed to investigate the system’s automatic control algorithm, with emphasis on the overnight period of 9 p.m. to 7 a.m. The study was conducted in clinical research centers and involved automatic dosing of insulin based on the continuous glucose monitor values. Concomitant glucose readings were obtained from the YSI 2300 STAT Plus, which were considered the reference measurements.
The mean overnight glucose values based on the HHM continuous glucose monitor and the STAT Plus were 135 and 129 mg/dL, respectively, the median percentage of overnight time spent at glucose values between 70 and 180 mg/dL was 94% and 91%, and the median percentage of overnight time spent at glucose values less than 70 mg/dL was 0% with both methods.
"We are encouraged by the performance of the HHM system in this feasibility study, and particularly by the steady, within-range control it maintained in the patients overnight," Dr. Finan said. "We observed only small amounts of low and high glucose measurements, as determined both by the continuous glucose monitors and the laboratory gold standard" YSI 2300 STAT Plus, he added.
A major limitation of this study was the fact that it was performed at clinical research centers, Dr. Finan said. "The assurance of patient safety with close medical supervision is standard practice for this type of feasibility study, but the clinical research center atmosphere does indeed come with a set of artificialities," Dr. Finan said. "We are working with regulatory agencies to devise a clinical plan that moves the patients from the clinic to more ambulatory conditions."
The study was sponsored by Animas Corp. Dr. Finan is an employee of the company.