Experimental immunotherapy for type 1 diabetes

An immunotherapy approach for treating type 1 diabetes has been found to be safe for the first time, and seems to stop the condition from getting worse.

Immunotherapies aim to modulate a person’s immune system, usually to relieve autoimmune conditions such as multiple sclerosis, rheumatoid arthritis or lupus. Type 1 diabetes is also an autoimmune disorder, in which the immune system’s T-cells mistakenly attack the pancreas’s insulin-producing beta cells.

But no immunotherapy had proven safe for treating the condition – let alone stopped it in its tracks. Preliminary results from a small trial now suggest that peptide immunotherapy may do just that.

The therapy involves injecting a person’s blood with short segments of proinsulin, a molecule produced by beta cells that is then turned into insulin. These fragments train attacking T-cells to recognise them as harmless and thus to stop attacking beta cells that make proinsulin.

The treatment was given to 21 people diagnosed with type 1 diabetes in the past 100 days, while another eight people were given a saline placebo. Both groups received injections every few weeks or so for six months.

Safe and stable

By 12 months after the start of the study, the placebo group had needed to increase their injected insulin doses by an average of 50 per cent. But those who received the immunotherapy remained stable, with no need to increase their insulin doses and no signs of accelerated beta cell destruction. No adverse reactions were seen.

“We’re looking at a drug that could be usable in five to 10 years, if everything goes well,” says Mark Peakman from King’s College London, who worked on the project. Ideally, the drug would be given to children who start developing the condition, and possibly to individuals with a high genetic risk for type 1 diabetes.

“The fact that this small study, designed to assess safety, suggests there may be a beneficial outcome is exciting, as we desperately need safe immune interventions that can prevent the decline of the patient’s own insulin secretion in type 1 diabetes,” says Andrew Hattersley at the University of Exeter.

The incidence of type 1 diabetes in Europe has been rising by about 4 per cent each year, particularly in children and teenagers, although it is unclear why. “It’s something to do with our modern lifestyle, but there are 20 or so theories at least,” says Peakman.