Type 1 diabetes drug strikingly effective in clinical trial

An experimental drug designed to block the advance of type 1 diabetes in its earliest stages has proven strikingly effective over two years in about half of the patients who participated in the phase 2 clinical trial.

Patients who benefited most were those who still had relatively good control of their blood sugar levels and only a moderate need for insulin injections when the trial began. With the experimental drug, teplizumab, they were able to maintain their level of insulin production for the full two years - longer than with most other drugs tested against the disease.

Results are published online in the journal Diabetes, and will appear in the November issue of the print edition.

The treatment did not benefit all patients. Some lost half or more of their ability to produce insulin – a drop similar to many of the controls not receiving the drug. Reasons for the different responses are unclear, but likely involve differences in the metabolic condition of the patients and in the severity of their disease at the trial’s start, the researchers said.

“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,” said Jeffrey Bluestone, PhD, co-leader of the research and A.W. and Mary Clausen Distinguished Professor at UC San Francisco, who collaborated in developing the drug.

The clinical trial was led by Kevan Herold, MD, PhD, a professor of immunobiology and deputy director for translational science at Yale University. He and Bluestone have collaborated on four previous clinical trials of the experimental drug.

“We are very excited by the efficacy of the drug,” Herold said. “Some of our patients and families have described a real impact on their diabetes.”

The results underscore the importance of diagnosing and treating diabetes in its earliest stages, the researchers said. Current treatment studies include “pre-diabetes” patients who have abnormal blood sugar levels but do not need to take insulin.

Formerly referred to as juvenile diabetes because it disproportionately strikes children, type 1 diabetes is caused by an autoimmune condition in which the body’s immune system destroys insulin-producing beta cells in the pancreas. Even with insulin treatments, the blood glucose levels fluctuate abnormally, and as the disease progresses, diabetes increases the risk of kidney failure, heart disease and other serious disorders.

According to the Juvenile Diabetes Research Foundation, as many as 3 million American have type 1 diabetes, and each year, more than 15,000 children and 15,000 adults are diagnosed with the disease in the United States. For reasons still unknown, the incidence of type 1 diabetes is increasing, and the age of onset is decreasing.