GAD-alum targeted a protein called GAD (glutamic acid decarboxylase). GAD, which is found in the brain and in insulin-secreting cells of the pancreas, isn't a problem in people without type 1 diabetes. But in type 1 diabetes, the body's immune system attacks the pancreas, and GAD is part of that attack. So the basic idea was to curb GAD to try to save insulin-secreting pancreatic cells.
In the new study, done in Sweden by researchers including Johnny Ludvigsson, MD, PhD, of Linkoping University, patients either got two GAD-alum shots or two placebo shots. They all also got routine medical care for type 1 diabetes, including insulin shots.
GAD-alum treatment helped preserve insulin-secreting pancreatic cells, but only in patients whose type 1 diabetes had been diagnosed within the past six months.
GAD-alum shots didn't cure type 1 diabetes. All of the patients still needed insulin shots and their insulin secretion still declined during the study, which lasted for two and one-half years. But the decline in those cells wasn't as steep in the patients who got the GAD-alum shots.
GAD-alum appeared to be safe, but larger, longer studies are needed, notes an editorial published with the study.
"We should never forget that we are caring for children with a chronic disease. Before we think of efficacy, we must give first consideration to the short- and long-term safety of any immune intervention," writes editorialist Denise Faustman, MD, PhD, of Massachusetts General Hospital and Harvard Medical School.
Ludvigsson's team isn't presenting their study as the final word on GAD treatment, but as a first step.
The study was backed by Diamyd Medical, the Swedish company that made GAD-alum. In the journal, Ludvigsson reports getting grants from Diamyd Medical; one of Ludvigsson's fellow researchers is a Diamyd Medical employee. Editorialist Faustman discloses receiving lecture fees from TolerRX, a drug company that is working on immune system therapies for diseases including diabetes.