Study Shows Teplizumab May Preserve Function of Body's Insulin-Producing Cells
By Charlene Laino
WebMD Health News
Reviewed By Laura J. Martin, MD
June 28, 2011 (San Diego) -- The experimental drug teplizumab shows promise for delaying the progression of type 1 diabetes in people newly diagnosed with it, researchers say.
In a study of 513 patients with type 1 diabetes, the drug failed to reach its primary goal of substantially improving blood sugar control and reducing the amount of insulin needed.
But teplizumab appeared to preserve the function of the body's own insulin-producing beta cells in the pancreas, reports Nicole Sherry, MD, director of the diabetes center at the Massachusetts General Hospital for Children in Boston.
"Preserving your own beta cell function is far better than relying on insulin [injections or a pump]," says Kevan Herold, MD, a Yale University endocrinologist who is heading another study of teplizumab.
"Beta cells make the right amount of insulin at the right place and the right time," he tells WebMD. "They turn it off when you don't need it, and turn it on when you do need it."
Sherry and Herold reporting being consultants to MacroGenics, which is developing teplizumab.
The findings were simultaneously reported online in The Lancet and here at the American Diabetes Association meeting.
Teplizumab vs. Placebo
Type 1 diabetes is a disease in which the body's immune system attacks and destroys the insulin-producing beta cells of the pancreas.
The study involved people ages 8 to 35 who were diagnosed with type 1 diabetes no more than 12 weeks before entering the study.
Patients were given infusions of either placebo or of one of three regimens of teplizumab. After six months, the treatment was repeated.
After one year, a similar percentage of people in each group -- about 20% -- had better blood sugar control and needed less insulin. But 5% of participants who received teplizumab no longer needed insulin at the end of one year, compared to none of those who received a placebo, Sherry says.
Further researched showed that 40% of patients who received the highest dose of the drug had better beta cell preservation, compared with 28% of those in the placebo group.
Younger patients, especially children ages 8 to 11, experienced the greatest gains in beta cell function, she says.
"This is important because the management of diabetes in children is very challenging," with higher rates of dangerously high and dangerously low blood sugar, she says.
Patients who started treatment sooner -- within six weeks of diagnosis rather than 12 -- also had greater benefit.
Theoretically, the sooner you give the drug, the more beta cells there are to save, Herold says. In type 1 diabetes, it usually takes about three years for the cells to become so damaged that patients require insulin to control their blood sugar.
Possible Side Effects
Nearly all (99%) patients in both the teplizumab and placebo groups experienced some type of side effect. The most common side effect among people on teplizumab was a transient mild to moderate rash (53% vs. 20% on placebo).
The rate of serious side effects was also similar among the groups, with 10% of patients on teplizumab and 9% on placebo affected.
A total of 4% of patients in the teplizumab groups had to stop taking the drug due to a low white blood cell count or an increase in liver enzymes vs. 2% in the placebo group.
In an editorial accompanying the study, Jean-Francois Bach, MD, of University Paris Descartes in France, writes that while the findings are encouraging, they were based mainly on unplanned analyses done after the study was completed. There is a need for further studies, perhaps using slightly higher doses of teplizumab sooner after diagnosis, he says.
"Ideally, type 1 diabetes should be regarded as a medical emergency and treatment with teplizumab could be started within a few days after diagnosis, as compared with several weeks or months as is done now," Bach writes.
71st Scientific Sessions of the American Diabetes Association, San Diego, June 24-28, 2011.
Nicole Sherry, MD, director, diabetes center, Massachusetts General Hospital for Children, Boston; consultant to MacroGenics.
Kevan Herold, MD, department of endocrinology, Yale University; consultant to MacroGenics.
Jean-Francois Bach, MD, University Paris Descartes, France.
Sherry, N. The Lancet online, June 28, 2011.
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