August 9, 2013
Diabetes Drug Teplizumab Proves Effective In Clinical Trials
redOrbit Staff & Wire Reports - Your Universe Online
An experimental drug developed to help prevent the advance of type 1 diabetes in its earliest stages has proven effective for approximately half of the patients involved in a two-year, phase 2 clinical trial, according to new research published online in Diabetes.
The study, which is also scheduled to appear in the November issue of the journal's print edition, focused on 52 patients who had been diagnosed with “new-onset type 1 diabetes” within eight weeks of the start of the trial, the researchers explained. The participants, most of whom were under 14 years of age, were treated with the immunosuppressive drug teplizumab for two weeks at diagnosis, then again one year later.
The study participants then had their capacity to produce their own insulin in order to control their blood sugar levels compared with a control group that had not received teplizumab. Since participants received daily insulin injections prior to and during the trial, the researchers instead measured blood levels of C-peptide – a molecule also produced in the pancreas, typically at the same rate as insulin.
Approximately half of the study participants benefited from the experimental treatment, especially those who had relatively good control of blood sugar levels and/or only a moderate need for insulin injections prior to the start of the trial, the study authors said.
However, they noted that some patients saw their ability to produce insulin decrease by 50 percent or more – a drop similar to many of the control group members who did not receive teplizumab. The researchers said that they are not certain what caused the different results in different patients, but that it likely involves differences in the patients' metabolic condition and the severity of their condition when the study began.
“The benefits of treatment among the patients who still had moderately healthy insulin production suggests that the sooner we can detect the pre-diabetes condition and get this kind of drug onboard, the more people we can protect from the progressive damage caused by an autoimmune attack,” Jeffrey Bluestone, PhD, co-leader of the research and a professor at the University of California, San Francisco (UCSF) who helped develop the drug, said in a statement.
According to Bluestone and his colleagues, teplizumab is one of several drugs currently being tested for their ability to control autoimmune reactions. This particular drug uses an antibody targeted against CD3, a molecule that acts as a T-cell co-receptor, to bind to those T-cells and restrain them from attacking the beta cells that store and release insulin in the body. The use of immunotherapies, currently used to treat organ transplant rejection and autoimmune diseases, is being tested as a diabetes therapy based on preclinical models and clinical trials.
The trial was led by Kevan Herold, MD, PhD an immunobiology professor at Yale University. Herold said that he and his colleagues were “very excited by the efficacy of the drug… Some of our patients and families have described a real impact on their diabetes,” and the researchers added that their findings emphasize the importance of diagnosing and treating type 1 diabetes at its earliest stages.
The research was a project of the Immune Tolerance Network, an international clinical research group aiming to accelerate the clinical development of immune tolerance therapies, and was supported by grants from the US National Institutes of Health (NIH). In addition, the authors have disclosed that Bluestone owns a patent on the teplizumab molecule, and that Herold has received grants from a pharmaceutical company which owns rights to the drug.