A two-week course of a new immuno-suppressant drug can stop type 1 diabetes in its tracks. The US clinical trial is the first to show that a short-term therapy can stop the need for injected insulin increasing over time.
Robert Goldstein, head of the US Juvenile Diabetes Research Foundation, which part-funded the research, says: “These remarkable results provide enormous hope for finding a cure for people with type 1 diabetes. For the first time it has been shown that progression of the destructive autoimmune response can be stopped with few side effects and islet function preserved.”
Type 1 diabetes is caused by the loss of insulin-producing islet cells in the pancreas. The body’s own immune system destroys the cells – although no one knows why.
Twelve patients whose insulin production had dropped began treatment within six weeks of their diagnosis. At the end of the one-year trial, 75 per cent showed little if any further loss in their ability to secrete insulin. In contrast, 10 of 12 control patients needed to step up their insulin injections over the course of the year.
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Some of the treated patients received the drug almost two years ago – and their insulin production has remained stable, says Kevan Herold of the Naomi Berrie Diabetes Center at Columbia Presbyterian Medical Center, who led the work.
Activated to attack
Previous attempts to slow the development of type 1 diabetes using a long-term immuno-suppressant treatment have been unsuccessful – usually because patients developed additional serious diseases, such as cancer.
“We think the drug worked so well because it targets cells involved in the disease, and is not a broad spectrum immunosuppressive agent,” Herold told New Scientist. “The mechanism of the action is different from agents that have been tested previously, and which have severe side effects. This drug appears to be safe. The side effects are very mild and brief.”
The new drug was developed by Jeffrey Bluestone of the University of California, San Francisco Diabetes Center. It is a monoclonal antibody designed to disarm T cells that have been activated to attack islet cells.
Diabetes prevention
In the long-term, the best way to deal with diabetes will be to restore full insulin-production by transplanting cells into the pancreas, or to prevent the disease developing in the first place. This might be achieved by using a sensitive screening programme and immuno-suppressive treatment before symptoms appear.
“But preserving some insulin production is very important,” Herold stresses. “People with diabetes who make some insulin have a much easier time in controlling their disease than those who do not.”
The team now plan a new trial on more than 80 people with type 1 diabetes, involving three two-week courses of injections. They hope this might increase the percentage that respond well.
Journal reference: New England Journal of Medicine (vol 346, p1692)
