ROCKVILLE, Md., June 27, 2011 /PRNewswire-USNewswire/ -- Results of two studies testing drugs to slow or stop the immune system's attack on insulin-producing cells in people newly diagnosed with type 1 diabetes will be presented at the American Diabetes Association's (ADA) 71st Scientific Sessions in San Diego and simultaneously published online in the Lancet. The studies were conducted by the National Institutes of Health's international network of researchers, Type 1 Diabetes TrialNet Study Group, led by the National Institute of Diabetes and Digestive and Kidney Diseases.
Both TrialNet studies aimed to preserve secretion of insulin, the hormone that controls blood glucose levels; one with the drug abatacept, and the other with a vaccine called glutamic acid decarboxylase (GAD). When type 1 diabetes is diagnosed, most patients retain a limited ability to make insulin, which is generally lost rapidly over the following one to two years. All study participants received intensive management of their diabetes during the trial, with a goal of keeping HbA1c levels within current ADA recommendations.
In the first study, abatacept (Orencia), an immune system modulator currently used to treat several inflammatory diseases, was evaluated in 112 people, ages 6 to 36, with newly diagnosed type 1 diabetes. Participants were randomized to receive injections of either abatacept or placebo over two years. The group treated with abatacept had a 9.6 month delay in the progression of loss of insulin production. After two years, a marker for the production of insulin was 59 percent higher in the participants treated with abatacept compared to the placebo group. Long-term retention of the ability to make even small amounts of insulin is associated with better glucose control and improved outcomes in diabetes.
In the second study, GAD-alum, an antigen based therapy aiming to suppress the immune response, was tested in 145 people, ages 3 to 45, with newly diagnosed type 1 diabetes. Participants were randomized into three groups to receive two or three doses of GAD-alum or alum alone over 4 to 12 weeks. During one year of treatment, the vaccine showed no evidence of preserving insulin secretion.
Adverse effects were minimal for both drugs, especially among children, who account for the majority of people with type 1 diabetes.
"We learn something important from every study, and we build on everything we learn. Both positive and negative studies help us develop more effective strategies to prevent and treat type 1 diabetes," said TrialNet Study Group Chair Jay Skyler, M.D. "We will continue to follow people in both studies. It is still early, but there is good reason to believe that some of the drugs being developed to alter immune responses, either alone or in combination with other therapies, will lead to treatments that prevent, postpone, or stop progression of type 1 diabetes."
Type 1 diabetes is an autoimmune disease that accounts for 5 to 10 percent of diagnosed cases of diabetes in the United States—up to 2.5 million people. It develops when a person's own immune system destroys beta cells in the pancreas. Beta cells sense blood glucose and produce the hormone insulin, which regulates glucose levels and converts it to energy. Formerly called juvenile onset diabetes, type 1 diabetes usually develops in children and young adults. To maintain good control of their blood glucose levels, people with this form of diabetes typically need three or more insulin injections a day or treatment with an insulin pump, as well as careful monitoring of blood glucose and attention to diet and exercise. Well controlled glucose is critical to preventing or delaying serious damage to the eyes, nerves, kidneys, heart, and blood vessels.
The destruction of insulin producing cells by the immune system begins well before the symptoms of diabetes occur and continues long after it is diagnosed, often until no insulin production remains. During the early months after diabetes is diagnosed, most people still have some functioning beta cells. These cells, with the help of insulin injections, make it easier to control blood glucose. If this period can be extended, researchers hope that more people will be able to achieve better control of their blood glucose. In some cases, intervention may be possible before clinical diabetes develops.
TrialNet researchers are conducting a series of studies to test ways to prevent or delay progression of type 1 diabetes. At this week's ADA meeting, TrialNet researchers will announce two ongoing studies aimed at preventing or delaying type 1 diabetes in people at high risk for the disease: relatives of people who already have it. One trial is testing an experimental drug called teplizumab, another immune system modulator; the other study is testing oral insulin, which may induce tolerance, or a quieting of the immune responses that lead to type 1 diabetes. Several other TrialNet reports will be presented that expand our understanding of how type 1 diabetes develops.
Type 1 diabetes appears to involve both genetic risk factors and less understood environmental factors that may interact to initiate the development of diabetes. To identify people at high risk for type 1 diabetes, TrialNet offers free screening for relatives of people with the disease. Screening involves a simple blood test for markers (autoantibodies) that often appear years before diabetes develops. Knowing the number and type of markers makes it possible to identify those at different risk levels for developing type 1 diabetes. Among people with a relative with type 1 diabetes, the chances of developing the disease are 15 times greater than for those with no family history. Screening can refine this risk estimate.
Nearly 200 U.S. TrialNet locations offer screening and conduct studies to identify causes of type 1 diabetes and test ways to prevent or delay the disease. To find a TrialNet location or to learn more, visit www.DiabetesTrialNet.org or call 1-800-425-8361.
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