Immunotherapy drugs represent a promising new way to treat cancer, but researchers have been hesitant to apply the same principals to the treatment of autoimmune diseases, like type 1 diabetes, over concerns that it could exacerbate the condition. Now, researchers at the Cardiff University School of Medicine have found that an immunotherapy designed to treat diabetes was both safe and effective when tested in a small clinical trial.
In patients with type 1 diabetes, their insulin-producing pancreatic β-cells are attacked by the body’s own immune cells, namely effector T-cells. Without the necessary secretion of insulin, patients must rely on insulin injections to control blood glucose levels.
It’s estimated that up to 1.25 million people in the US have been diagnosed with type 1 diabetes, and that number has been growing rapidly. Unlike type 2 diabetes, development of the autoimmune disease has not been linked with diet or lifestyle, and is believed to be controlled by genetic factors.
In their study, the Cardiff University researchers recruited 27 patients who were newly-diagnosed with type 1 diabetes and randomly assigned them to receive immunotherapy injections or a placebo. The results of the study were published in the journal, Science Translational Medicine.
While individuals given the placebo required escalating does of exogenous insulin over the follow-up period, the participants in the treatment arm did not. Along with this demonstrated efficacy, the researchers noted no toxic side effects of the immunotherapy.
The peptide-based immunotherapy contained proinsulin, an insulin precurser designed to activate regulatory T-cells (Tregs). These Tregs then prevent the effector T-cells from damaging the insulin-producing β-cells of the pancreas.
The study authors admit that larger studies will need to be performed in order to characterize the metabolic effects of this immunotherapy in patients with type 1 diabetes. They are, however, encouraged by the “favourable safety profile” and believe that their findings “suggests immunotherapy could be a viable option for treating type 1 diabetes.”
“Immunotherapy using peptides has been successful for some patients with allergies, but has not yet been deployed in autoimmune diseases, which may involve greater safety risks,” said a piece accompanying the journal article. “This small trial showed that treatment seemed to modify T-cell responses and did not interfere with residual β-cell function.”