Immunotherapy for type I diabetes safe and well-tolerated, report study authors

A potential new therapy for type I diabetes patients has been found to be safe and does not accelerate decline in β cell function — important in the production of insulin — in a recently published clinical trial.

The study from researchers based across the UK has been published in Science Translational Medicine and evaluated an antigen-specific immunotherapy (ASI) approach in patients who had recently been diagnosed with type I diabetes.

ASI has been shown to be an effective way to control disease progression in preclinical models as it reduces the number of effector T cells and promoted CD4 T cells, which are part of the immunological pathways involved in β cell loss.

The specific strategy used in this study was called peptide immunotherapy (PIT), involving the administration of short peptides, thereby, avoiding potential immunoglobulin hypersentivity as the whole antigen is not used.

Just under 30 patients met the relevant criteria and were assessed in five hospitals in the UK. They were randomized to treatment with some receiving a high-frequency (10 µg proinsulin C19-A3 peptide every two weeks) and others a low-frequency (10 µg proinsulin C19-A3 peptide every four weeks alternated with saline every four weeks) or receiving a placebo.

The treatment comprised an intradermal injection and was administered for a total of 12 over a six month period. The follow up periods were every three months and lasted a year, during which the team assessed residual C-peptide production.

It was found that the placebo group experienced a significant decline in residual C-peptide production at each follow up when compared to baseline, meaning they required an increase in daily insulin over the study period. However, the two groups receiving PIT did not have any significant change and did not require additional insulin throughout the study. The treatment arms were also well tolerated with no systemic or local hypersensitivity witnessed.

Prof Mark Peakman, from King's College London, told the BBC News website: “This is a landmark in the sense it's the first time it has been done. Importantly, [the trial] shows the overall safety is good and there is some evidence we're restoring the balance and getting some regulatory T cells activated.”

This early-stage clinical trial, although showing promise, does need further follow up and research, noted the study authors.