An experimental drug appears to stop juvenile diabetes in its tracks, allowing patients to reduce insulin injections and control their disease better, according to a small study to be published today.
The drug, given for two weeks soon after patients were given diagnoses of Type 1, or juvenile, diabetes, appeared to halt the destruction of the patients' insulin-producing cells for at least a year, preserving their ability to produce some of their own insulin.
Scientists cautioned that since only 12 patients had been treated, the results were preliminary but still tantalizing.
''For the very first time in humans with this disease you can apparently alter the clinical course with something that's relatively nontoxic,'' said Dr. Robert Goldstein, chief scientific officer of the Juvenile Diabetes Research Foundation, which sponsored the study with the National Institutes of Health. ''That's pretty exciting. Not quite a cure, but I would say an important step on that road.''Continue reading the main story
The study is in today's issue of The New England Journal of Medicine, along with another paper with more sobering news: a large clinical trial showed that giving insulin injections to people at risk of developing Type 1 diabetes did not prevent the disease. The results contradicted those of smaller studies that had raised hopes that a simple means of preventing diabetes was close at hand.
''It's very disappointing,'' said Dr. Jay S. Skyler, chief of endocrinology at the University of Miami and chairman of the study group. ''We had hoped this would be a relatively simple solution.''
That study did hold one bright spot. Though scientists failed to prevent diabetes, they found in recruiting patients for the clinical trial that they were able to use various tests to predict who was at risk for the disease.
''The best news to come out of that study is that we can identify children before they get diabetes,'' said Dr. Christopher D. Saudek, professor of medicine at Johns Hopkins University and president of the American Diabetes Association.
In Type 1 diabetes, which ordinarily appears in children and young adults, the body's immune system mistakenly attacks and destroys the islet cells in the pancreas that produce insulin. About 1 million Americans have Type 1 diabetes, compared with about 16 million who have Type 2, or adult-onset diabetes, which is caused in part by the body's inability to use insulin.
Exercise and weight loss can help prevent Type 2 diabetes. But the key to preventing or stopping Type 1, doctors believe, is to stop the immune system from attacking the insulin-producing cells.
Immune-suppressing drugs like cyclosporine have been shown to work, but such drugs knock out the entire immune system, raising the risk of infections and cancer, so most doctors think such drugs are unsuitable for long-term use by children.
The drug used in the new study appears to suppress the immune system somewhat more selectively, so that the ability to fight infections is not greatly impaired, said Dr. Jeffrey A. Bluestone, director of the diabetes center at the University of California at San Francisco and developer of the drug.
The treatment is a new version of an older drug, OKT3, which is used to help prevent transplant rejection. The new version, which will require years more of study before it can be approved for sale, has fewer side effects and works somewhat differently, Dr. Bluestone said. The drug -- a monoclonal antibody that binds to the CD3 molecule on the immune system's T cells -- produced fevers, rash and anemia in some patients, he said, but these side effects were not serious.
Intriguingly, Dr. Bluestone said, the immune suppression continued for months after patients stopped getting the drug, perhaps because it somehow induced the immune system to tolerate the body's islet cells. ''It's like we reset the rheostat,'' he said, ''so the immune system that's gone out of control and started killing the islets is now in control again.''
Doctors gave the drug by intravenous infusion every day for two weeks to 12 patients, ages 7 to 27, who had received a diagnosis of diabetes in the previous six weeks. Nine of the 12 had little if any loss in their ability to make insulin after a year, while 10 of 12 patients in a control group had a significant decrease. The need for injected insulin fell slightly in the treated group over the year and rose in the control group. The treated group also had lower blood sugar levels, on average, after a year.
''The fact that they are making their own insulin is the most important thing,'' said Dr. Kevan C. Herold, associate professor at Columbia University and a lead investigator of the study along with Dr. Bluestone.
The treatment cannot cure diabetes because patients have already lost too many islet cells by the time of diagnosis. But maintaining the body's ability to produce even a little of its own insulin makes blood sugar levels easier to control, doctors said. And better control reduces the risk of complications like blindness and kidney disease, and of losing consciousness because of low blood sugar.
''The expectation will not be to get people off insulin,'' said Dr. Francine R. Kaufman, head of endocrinology at Children's Hospital in Los Angeles and president-elect of the American Diabetes Association. ''The expectation will be to keep them on a low to moderate dose of insulin and have them have better blood glucose control.''
But if the new OKT3 could be given to people before their islet cells have been destroyed, it might be possible to prevent the onset of Type 1 diabetes. Dr. Saudek, of the diabetes association, said the finding from the large study demonstrated that mass screenings could identify children at risk for the disease who would be candidates for such a drug.Continue reading the main story