| CHICAGO, June 22
CHICAGO, June 22 Type 1 diabetics, who run the
risk of dangerously low blood sugar, may be a step closer to
getting help from a crude artificial pancreas device that can
read blood sugar levels and automatically turn off the flow of
insulin after a clinical trial showed the device is safe.
The long-awaited results of the clinical trial may pave the
way for U.S. approval of the device, made by Medtronic, which
already sells insulin pumps with an automatic shutoff feature in
50 countries outside the United States. The feature is meant to
guard against delivering insulin to diabetics their blood sugar
is already too low.
As many as 3 million Americans have type 1 diabetes, in
which the immune system destroys cells in the pancreas that make
Type 1 diabetes must monitor their blood sugar and take
insulin several times a day. Too little insulin can cause high
blood sugar, increasing the risk of long-term complications such
as eye damage, kidney failure and heart disease. But too much
insulin can cause blood sugar to drop too low, causing
hypoglycemia, which can result in seizures, unconsciousness,
brain damage and death.
U.S. regulators have refused to allow insulin pumps with an
automatic shutoff feature on the U.S. market without a large,
carefully controlled clinical trial proving they are safe.
The latest study, known as ASPIRE, which tested the system
in 247 people with diabetes in their homes, offered the proof.
It showed the device reduced the amount of time and the
duration that a diabetic's blood sugar fell below a certain
threshold - a measure known as area under the curve - by 37.5
percent. The device reduced the overall number of low blood
sugar episodes by 31.8 percent compared to diabetics using an
insulin pump without the shutoff feature.
The findings were published online on Saturday in the New
England Journal of Medicine and presented at the American
Diabetes Association meeting in Chicago.
Dr. Francine Kaufman, vice president of global medical
affairs for Medtronic's diabetes business, said the study showed
that shutting off the flow of insulin mimics what happens in
healthy people in response to low blood sugar.
Kaufman, a pediatric endocrinologist who still has an active
practice in Los Angeles, said the device is intended to help
diabetics who may find themselves in a situation where they
cannot help themselves.
"Many of my patients are 3 years old. So, if mom is not
around, they don't know how to do this on their own," she said.
"We're going to take that and automate it for them."
Dr Richard Bergenstal, of the International Diabetes Center
at Park Nicollet Health Services in Minneapolis, the study's
lead author, highlighted the study's findings.
"That is a significant reduction in the duration and
severity of low blood sugar," he told a news briefing at the
Diabetes advocates, researchers and medical device companies
for decades have spoken wistfully about the "holy grail" of an
artificial pancreas, a complex system of pumps and sensors aimed
at automating the complex care and treatment of type 1 diabetes
by mimicking the function of a real pancreas.
The Medtronic device is decidedly not that. But it is the
first device before the U.S. Food and Drug Administration to
detect dangerous blood sugar levels and automatically take
action to correct it.
"The study results are important as we continue to move
toward our goal of developing a fully automated system, or
artificial pancreas, that will one day require very minimal
interaction from the patient," Medtronic's Kaufman said.
In designing the study, researchers had to find a population
of patients who were especially prone to having hypoglycemia at
night. Bergenstal said as many as 320 people tried to enroll in
the study, but only 247 qualified.
'THEY DIDN'T WAKE UP'
Spears Mallis, a 34-year-old administrator for the
Longstreet Cancer Center in Gainesville, Georgia, was one.
Mallis, an avid runner, has had type 1 diabetes for almost
17 years. For the past 16 or so, he has used an insulin pump,
often pared with a continuous glucose monitor, to keep track of
his blood sugar and deliver a steady flow of insulin.
But Mallis still suffers from occasional bouts of
hypoglycemia, which were especially disturbing when he had a job
that required him to travel.
Like many in the diabetes community, Mallis was aware of
efforts several years ago by the Juvenile Diabetes Research
Foundation and others to push the FDA to set guidelines for
approving the Medtronic device. Some had even hoped the agency
would allow these devices on the U.S. market without additional
testing. But in 2011, the FDA made clear the company would need
a clinical trial, and Mallis was on board.
During the three-month trial, Mallis said the suspend device
kicked in several times. "In one of my races, it went off and I
had it go straight to suspend."
He said the device's alarm feature was loud enough to wake
his wife, but there were times he would sleep through it.
"After you have type 1 diabetes for awhile, your senses become
lessened for feeling low blood sugar."
Mallis said the device would stop the flow of insulin until
he woke and took action himself.
His experience was typical. Bergenstal said for many
individuals, the device was suspended for the full two-hour
maximum, despite the alarm. "They didn't wake up."
The study was also designed to see if cutting off insulin for
this period would cause insulin to "rocket back up," Bergenstal
said. But at the end of the two-hour period, it just "gradually
drifted back up into the normal range," he said.
The study also showed the device had no impact on a measure
of long-term control of blood sugar called A1c.
Kaufman said Medtronic has presented the study results to
the FDA and received an approvable letter for its
next-generation pump device that includes the feature, meaning
the device can be approved provided the company meets certain
conditions. Chief Executive Omar Ishrak has said he expects
device approval during the current calendar year.
"We are just going back and forth on overall quality issues.
We're working very collaboratively with FDA to work through some
of the issues," Kaufman said.
Meanwhile, the company and its rivals, including Johnson &
Johnson's Animas unit, are working on next-generation
devices that add more automated features.
On Friday, the company presented results at the diabetes
meeting on a study of a system designed to predict when
diabetics are heading for a dangerous low and take preemptive
action by decreasing the amount of insulin the pump delivers.
The night-time study of 20 adults with type 1 diabetes
showed the software control program helped people stay within a
target range for 90 percent of the time.
Ramakrishna Venugopalan, director for research and
development at Animas, sees the development of an artificial
pancreas as a step-wise process, in which products begin to
automate more and more of the functions now managed by patients.
The company this month won approval for another feasibility
study, its third in three years.
Venugopalan still can't say when a fully automated
artificial pancreas will be available, but adds, "I don't think
this is a pipe dream."